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

   1 // This file is Copyright its original authors, visible in version control
   2 // history.
   3 //
   4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
   5 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
   7 // You may not use this file except in accordance with one or both of these
   8 // licenses.
   9
  10 //! Some macros that implement [`Readable`]/[`Writeable`] traits for lightning messages.
  11 //! They also handle serialization and deserialization of TLVs.
  12 //!
  13 //! [`Readable`]: crate::util::ser::Readable
  14 //! [`Writeable`]: crate::util::ser::Writeable
  15
  16 /// Implements serialization for a single TLV record.
  17 /// This is exported for use by other exported macros, do not use directly.
  18 #[doc(hidden)]
  19 #[macro_export]
  20 macro_rules! _encode_tlv {
  21         ($stream: expr, $type: expr, $field: expr, (default_value, $default: expr)) => {
  22                 $crate::_encode_tlv!($stream, $type, $field, required)
  23         };
  24         ($stream: expr, $type: expr, $field: expr, (static_value, $value: expr)) => {
  25                 let _ = &$field; // Ensure we "use" the $field
  26         };
  27         ($stream: expr, $type: expr, $field: expr, required) => {
  28                 BigSize($type).write($stream)?;
  29                 BigSize($field.serialized_length() as u64).write($stream)?;
  30                 $field.write($stream)?;
  31         };
  32         ($stream: expr, $type: expr, $field: expr, vec_type) => {
  33                 $crate::_encode_tlv!($stream, $type, $crate::util::ser::WithoutLength(&$field), required);
  34         };
  35         ($stream: expr, $optional_type: expr, $optional_field: expr, option) => {
  36                 if let Some(ref field) = $optional_field {
  37                         BigSize($optional_type).write($stream)?;
  38                         BigSize(field.serialized_length() as u64).write($stream)?;
  39                         field.write($stream)?;
  40                 }
  41         };
  42         ($stream: expr, $type: expr, $field: expr, upgradable_required) => {
  43                 $crate::_encode_tlv!($stream, $type, $field, required);
  44         };
  45         ($stream: expr, $type: expr, $field: expr, upgradable_option) => {
  46                 $crate::_encode_tlv!($stream, $type, $field, option);
  47         };
  48         ($stream: expr, $type: expr, $field: expr, (option, encoding: ($fieldty: ty, $encoding: ident))) => {
  49                 $crate::_encode_tlv!($stream, $type, $field.map(|f| $encoding(f)), option);
  50         };
  51         ($stream: expr, $type: expr, $field: expr, (option, encoding: $fieldty: ty)) => {
  52                 $crate::_encode_tlv!($stream, $type, $field, option);
  53         };
  54         ($stream: expr, $type: expr, $field: expr, (option: $trait: ident $(, $read_arg: expr)?)) => {
  55                 // Just a read-mapped type
  56                 $crate::_encode_tlv!($stream, $type, $field, option);
  57         };
  58 }
  59
  60 /// Panics if the last seen TLV type is not numerically less than the TLV type currently being checked.
  61 /// This is exported for use by other exported macros, do not use directly.
  62 #[doc(hidden)]
  63 #[macro_export]
  64 macro_rules! _check_encoded_tlv_order {
  65         ($last_type: expr, $type: expr, (static_value, $value: expr)) => { };
  66         ($last_type: expr, $type: expr, $fieldty: tt) => {
  67                 if let Some(t) = $last_type {
  68                         #[allow(unused_comparisons)] // Note that $type may be 0 making the following comparison always false
  69                         (debug_assert!(t < $type))
  70                 }
  71                 $last_type = Some($type);
  72         };
  73 }
  74
  75 /// Implements the TLVs serialization part in a [`Writeable`] implementation of a struct.
  76 ///
  77 /// This should be called inside a method which returns `Result<_, `[`io::Error`]`>`, such as
  78 /// [`Writeable::write`]. It will only return an `Err` if the stream `Err`s or [`Writeable::write`]
  79 /// on one of the fields `Err`s.
  80 ///
  81 /// `$stream` must be a `&mut `[`Writer`] which will receive the bytes for each TLV in the stream.
  82 ///
  83 /// Fields MUST be sorted in `$type`-order.
  84 ///
  85 /// Note that the lightning TLV requirements require that a single type not appear more than once,
  86 /// that TLVs are sorted in type-ascending order, and that any even types be understood by the
  87 /// decoder.
  88 ///
  89 /// Any `option` fields which have a value of `None` will not be serialized at all.
  90 ///
  91 /// For example,
  92 /// ```
  93 /// # use lightning::encode_tlv_stream;
  94 /// # fn write<W: lightning::util::ser::Writer> (stream: &mut W) -> Result<(), lightning::io::Error> {
  95 /// let mut required_value = 0u64;
  96 /// let mut optional_value: Option<u64> = None;
  97 /// encode_tlv_stream!(stream, {
  98 ///     (0, required_value, required),
  99 ///     (1, Some(42u64), option),
 100 ///     (2, optional_value, option),
 101 /// });
 102 /// // At this point `required_value` has been written as a TLV of type 0, `42u64` has been written
 103 /// // as a TLV of type 1 (indicating the reader may ignore it if it is not understood), and *no*
 104 /// // TLV is written with type 2.
 105 /// # Ok(())
 106 /// # }
 107 /// ```
 108 ///
 109 /// [`Writeable`]: crate::util::ser::Writeable
 110 /// [`io::Error`]: crate::io::Error
 111 /// [`Writeable::write`]: crate::util::ser::Writeable::write
 112 /// [`Writer`]: crate::util::ser::Writer
 113 #[macro_export]
 114 macro_rules! encode_tlv_stream {
 115         ($stream: expr, {$(($type: expr, $field: expr, $fieldty: tt)),* $(,)*}) => { {
 116                 #[allow(unused_imports)]
 117                 use $crate::{
 118                         ln::msgs::DecodeError,
 119                         util::ser,
 120                         util::ser::BigSize,
 121                         util::ser::Writeable,
 122                 };
 123
 124                 $(
 125                         $crate::_encode_tlv!($stream, $type, $field, $fieldty);
 126                 )*
 127
 128                 #[allow(unused_mut, unused_variables, unused_assignments)]
 129                 #[cfg(debug_assertions)]
 130                 {
 131                         let mut last_seen: Option<u64> = None;
 132                         $(
 133                                 $crate::_check_encoded_tlv_order!(last_seen, $type, $fieldty);
 134                         )*
 135                 }
 136         } }
 137 }
 138
 139 /// Adds the length of the serialized field to a [`LengthCalculatingWriter`].
 140 /// This is exported for use by other exported macros, do not use directly.
 141 ///
 142 /// [`LengthCalculatingWriter`]: crate::util::ser::LengthCalculatingWriter
 143 #[doc(hidden)]
 144 #[macro_export]
 145 macro_rules! _get_varint_length_prefixed_tlv_length {
 146         ($len: expr, $type: expr, $field: expr, (default_value, $default: expr)) => {
 147                 $crate::_get_varint_length_prefixed_tlv_length!($len, $type, $field, required)
 148         };
 149         ($len: expr, $type: expr, $field: expr, (static_value, $value: expr)) => {
 150         };
 151         ($len: expr, $type: expr, $field: expr, required) => {
 152                 BigSize($type).write(&mut $len).expect("No in-memory data may fail to serialize");
 153                 let field_len = $field.serialized_length();
 154                 BigSize(field_len as u64).write(&mut $len).expect("No in-memory data may fail to serialize");
 155                 $len.0 += field_len;
 156         };
 157         ($len: expr, $type: expr, $field: expr, vec_type) => {
 158                 $crate::_get_varint_length_prefixed_tlv_length!($len, $type, $crate::util::ser::WithoutLength(&$field), required);
 159         };
 160         ($len: expr, $optional_type: expr, $optional_field: expr, option) => {
 161                 if let Some(ref field) = $optional_field {
 162                         BigSize($optional_type).write(&mut $len).expect("No in-memory data may fail to serialize");
 163                         let field_len = field.serialized_length();
 164                         BigSize(field_len as u64).write(&mut $len).expect("No in-memory data may fail to serialize");
 165                         $len.0 += field_len;
 166                 }
 167         };
 168         ($len: expr, $type: expr, $field: expr, (option: $trait: ident $(, $read_arg: expr)?)) => {
 169                 $crate::_get_varint_length_prefixed_tlv_length!($len, $type, $field, option);
 170         };
 171         ($len: expr, $type: expr, $field: expr, upgradable_required) => {
 172                 $crate::_get_varint_length_prefixed_tlv_length!($len, $type, $field, required);
 173         };
 174         ($len: expr, $type: expr, $field: expr, upgradable_option) => {
 175                 $crate::_get_varint_length_prefixed_tlv_length!($len, $type, $field, option);
 176         };
 177 }
 178
 179 /// See the documentation of [`write_tlv_fields`].
 180 /// This is exported for use by other exported macros, do not use directly.
 181 #[doc(hidden)]
 182 #[macro_export]
 183 macro_rules! _encode_varint_length_prefixed_tlv {
 184         ($stream: expr, {$(($type: expr, $field: expr, $fieldty: tt)),*}) => { {
 185                 use $crate::util::ser::BigSize;
 186                 let len = {
 187                         #[allow(unused_mut)]
 188                         let mut len = $crate::util::ser::LengthCalculatingWriter(0);
 189                         $(
 190                                 $crate::_get_varint_length_prefixed_tlv_length!(len, $type, $field, $fieldty);
 191                         )*
 192                         len.0
 193                 };
 194                 BigSize(len as u64).write($stream)?;
 195                 $crate::encode_tlv_stream!($stream, { $(($type, $field, $fieldty)),* });
 196         } }
 197 }
 198
 199 /// Errors if there are missing required TLV types between the last seen type and the type currently being processed.
 200 /// This is exported for use by other exported macros, do not use directly.
 201 #[doc(hidden)]
 202 #[macro_export]
 203 macro_rules! _check_decoded_tlv_order {
 204         ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, (default_value, $default: expr)) => {{
 205                 #[allow(unused_comparisons)] // Note that $type may be 0 making the second comparison always false
 206                 let invalid_order = ($last_seen_type.is_none() || $last_seen_type.unwrap() < $type) && $typ.0 > $type;
 207                 if invalid_order {
 208                         $field = $default.into();
 209                 }
 210         }};
 211         ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, (static_value, $value: expr)) => {
 212         };
 213         ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, required) => {{
 214                 #[allow(unused_comparisons)] // Note that $type may be 0 making the second comparison always false
 215                 let invalid_order = ($last_seen_type.is_none() || $last_seen_type.unwrap() < $type) && $typ.0 > $type;
 216                 if invalid_order {
 217                         return Err(DecodeError::InvalidValue);
 218                 }
 219         }};
 220         ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, (required: $trait: ident $(, $read_arg: expr)?)) => {{
 221                 $crate::_check_decoded_tlv_order!($last_seen_type, $typ, $type, $field, required);
 222         }};
 223         ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, option) => {{
 224                 // no-op
 225         }};
 226         ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, vec_type) => {{
 227                 // no-op
 228         }};
 229         ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, upgradable_required) => {{
 230                 _check_decoded_tlv_order!($last_seen_type, $typ, $type, $field, required)
 231         }};
 232         ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, upgradable_option) => {{
 233                 // no-op
 234         }};
 235         ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, (option: $trait: ident $(, $read_arg: expr)?)) => {{
 236                 // no-op
 237         }};
 238         ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, (option, encoding: $encoding: tt)) => {{
 239                 // no-op
 240         }};
 241 }
 242
 243 /// Errors if there are missing required TLV types after the last seen type.
 244 /// This is exported for use by other exported macros, do not use directly.
 245 #[doc(hidden)]
 246 #[macro_export]
 247 macro_rules! _check_missing_tlv {
 248         ($last_seen_type: expr, $type: expr, $field: ident, (default_value, $default: expr)) => {{
 249                 #[allow(unused_comparisons)] // Note that $type may be 0 making the second comparison always false
 250                 let missing_req_type = $last_seen_type.is_none() || $last_seen_type.unwrap() < $type;
 251                 if missing_req_type {
 252                         $field = $default.into();
 253                 }
 254         }};
 255         ($last_seen_type: expr, $type: expr, $field: expr, (static_value, $value: expr)) => {
 256                 $field = $value;
 257         };
 258         ($last_seen_type: expr, $type: expr, $field: ident, required) => {{
 259                 #[allow(unused_comparisons)] // Note that $type may be 0 making the second comparison always false
 260                 let missing_req_type = $last_seen_type.is_none() || $last_seen_type.unwrap() < $type;
 261                 if missing_req_type {
 262                         return Err(DecodeError::InvalidValue);
 263                 }
 264         }};
 265         ($last_seen_type: expr, $type: expr, $field: ident, (required: $trait: ident $(, $read_arg: expr)?)) => {{
 266                 $crate::_check_missing_tlv!($last_seen_type, $type, $field, required);
 267         }};
 268         ($last_seen_type: expr, $type: expr, $field: ident, vec_type) => {{
 269                 // no-op
 270         }};
 271         ($last_seen_type: expr, $type: expr, $field: ident, option) => {{
 272                 // no-op
 273         }};
 274         ($last_seen_type: expr, $type: expr, $field: ident, upgradable_required) => {{
 275                 _check_missing_tlv!($last_seen_type, $type, $field, required)
 276         }};
 277         ($last_seen_type: expr, $type: expr, $field: ident, upgradable_option) => {{
 278                 // no-op
 279         }};
 280         ($last_seen_type: expr, $type: expr, $field: ident, (option: $trait: ident $(, $read_arg: expr)?)) => {{
 281                 // no-op
 282         }};
 283         ($last_seen_type: expr, $type: expr, $field: ident, (option, encoding: $encoding: tt)) => {{
 284                 // no-op
 285         }};
 286 }
 287
 288 /// Implements deserialization for a single TLV record.
 289 /// This is exported for use by other exported macros, do not use directly.
 290 #[doc(hidden)]
 291 #[macro_export]
 292 macro_rules! _decode_tlv {
 293         ($reader: expr, $field: ident, (default_value, $default: expr)) => {{
 294                 $crate::_decode_tlv!($reader, $field, required)
 295         }};
 296         ($reader: expr, $field: ident, (static_value, $value: expr)) => {{
 297         }};
 298         ($reader: expr, $field: ident, required) => {{
 299                 $field = $crate::util::ser::Readable::read(&mut $reader)?;
 300         }};
 301         ($reader: expr, $field: ident, (required: $trait: ident $(, $read_arg: expr)?)) => {{
 302                 $field = $trait::read(&mut $reader $(, $read_arg)*)?;
 303         }};
 304         ($reader: expr, $field: ident, vec_type) => {{
 305                 let f: $crate::util::ser::WithoutLength<Vec<_>> = $crate::util::ser::Readable::read(&mut $reader)?;
 306                 $field = Some(f.0);
 307         }};
 308         ($reader: expr, $field: ident, option) => {{
 309                 $field = Some($crate::util::ser::Readable::read(&mut $reader)?);
 310         }};
 311         // `upgradable_required` indicates we're reading a required TLV that may have been upgraded
 312         // without backwards compat. We'll error if the field is missing, and return `Ok(None)` if the
 313         // field is present but we can no longer understand it.
 314         // Note that this variant can only be used within a `MaybeReadable` read.
 315         ($reader: expr, $field: ident, upgradable_required) => {{
 316                 $field = match $crate::util::ser::MaybeReadable::read(&mut $reader)? {
 317                         Some(res) => res,
 318                         _ => return Ok(None)
 319                 };
 320         }};
 321         // `upgradable_option` indicates we're reading an Option-al TLV that may have been upgraded
 322         // without backwards compat. $field will be None if the TLV is missing or if the field is present
 323         // but we can no longer understand it.
 324         ($reader: expr, $field: ident, upgradable_option) => {{
 325                 $field = $crate::util::ser::MaybeReadable::read(&mut $reader)?;
 326         }};
 327         ($reader: expr, $field: ident, (option: $trait: ident $(, $read_arg: expr)?)) => {{
 328                 $field = Some($trait::read(&mut $reader $(, $read_arg)*)?);
 329         }};
 330         ($reader: expr, $field: ident, (option, encoding: ($fieldty: ty, $encoding: ident, $encoder:ty))) => {{
 331                 $crate::_decode_tlv!($reader, $field, (option, encoding: ($fieldty, $encoding)));
 332         }};
 333         ($reader: expr, $field: ident, (option, encoding: ($fieldty: ty, $encoding: ident))) => {{
 334                 $field = {
 335                         let field: $encoding<$fieldty> = ser::Readable::read(&mut $reader)?;
 336                         Some(field.0)
 337                 };
 338         }};
 339         ($reader: expr, $field: ident, (option, encoding: $fieldty: ty)) => {{
 340                 $crate::_decode_tlv!($reader, $field, option);
 341         }};
 342 }
 343
 344 /// Checks if `$val` matches `$type`.
 345 /// This is exported for use by other exported macros, do not use directly.
 346 #[doc(hidden)]
 347 #[macro_export]
 348 macro_rules! _decode_tlv_stream_match_check {
 349         ($val: ident, $type: expr, (static_value, $value: expr)) => { false };
 350         ($val: ident, $type: expr, $fieldty: tt) => { $val == $type }
 351 }
 352
 353 /// Implements the TLVs deserialization part in a [`Readable`] implementation of a struct.
 354 ///
 355 /// This should be called inside a method which returns `Result<_, `[`DecodeError`]`>`, such as
 356 /// [`Readable::read`]. It will either return an `Err` or ensure all `required` fields have been
 357 /// read and optionally read `optional` fields.
 358 ///
 359 /// `$stream` must be a [`Read`] and will be fully consumed, reading until no more bytes remain
 360 /// (i.e. it returns [`DecodeError::ShortRead`]).
 361 ///
 362 /// Fields MUST be sorted in `$type`-order.
 363 ///
 364 /// Note that the lightning TLV requirements require that a single type not appear more than once,
 365 /// that TLVs are sorted in type-ascending order, and that any even types be understood by the
 366 /// decoder.
 367 ///
 368 /// For example,
 369 /// ```
 370 /// # use lightning::decode_tlv_stream;
 371 /// # fn read<R: lightning::io::Read> (stream: R) -> Result<(), lightning::ln::msgs::DecodeError> {
 372 /// let mut required_value = 0u64;
 373 /// let mut optional_value: Option<u64> = None;
 374 /// decode_tlv_stream!(stream, {
 375 ///     (0, required_value, required),
 376 ///     (2, optional_value, option),
 377 /// });
 378 /// // At this point, `required_value` has been overwritten with the TLV with type 0.
 379 /// // `optional_value` may have been overwritten, setting it to `Some` if a TLV with type 2 was
 380 /// // present.
 381 /// # Ok(())
 382 /// # }
 383 /// ```
 384 ///
 385 /// [`Readable`]: crate::util::ser::Readable
 386 /// [`DecodeError`]: crate::ln::msgs::DecodeError
 387 /// [`Readable::read`]: crate::util::ser::Readable::read
 388 /// [`Read`]: crate::io::Read
 389 /// [`DecodeError::ShortRead`]: crate::ln::msgs::DecodeError::ShortRead
 390 #[macro_export]
 391 macro_rules! decode_tlv_stream {
 392         ($stream: expr, {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}) => {
 393                 let rewind = |_, _| { unreachable!() };
 394                 $crate::_decode_tlv_stream_range!($stream, .., rewind, {$(($type, $field, $fieldty)),*});
 395         }
 396 }
 397
 398 /// Similar to [`decode_tlv_stream`] with a custom TLV decoding capabilities.
 399 ///
 400 /// `$decode_custom_tlv` is a closure that may be optionally provided to handle custom message types.
 401 /// If it is provided, it will be called with the custom type and the [`FixedLengthReader`] containing
 402 /// the message contents. It should return `Ok(true)` if the custom message is successfully parsed,
 403 /// `Ok(false)` if the message type is unknown, and `Err(`[`DecodeError`]`)` if parsing fails.
 404 ///
 405 /// [`FixedLengthReader`]: crate::util::ser::FixedLengthReader
 406 /// [`DecodeError`]: crate::ln::msgs::DecodeError
 407 macro_rules! decode_tlv_stream_with_custom_tlv_decode {
 408         ($stream: expr, {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}
 409          $(, $decode_custom_tlv: expr)?) => { {
 410                 let rewind = |_, _| { unreachable!() };
 411                 _decode_tlv_stream_range!(
 412                         $stream, .., rewind, {$(($type, $field, $fieldty)),*} $(, $decode_custom_tlv)?
 413                 );
 414         } }
 415 }
 416
 417 #[doc(hidden)]
 418 #[macro_export]
 419 macro_rules! _decode_tlv_stream_range {
 420         ($stream: expr, $range: expr, $rewind: ident, {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}
 421          $(, $decode_custom_tlv: expr)?) => { {
 422                 use $crate::ln::msgs::DecodeError;
 423                 let mut last_seen_type: Option<u64> = None;
 424                 let mut stream_ref = $stream;
 425                 'tlv_read: loop {
 426                         use $crate::util::ser;
 427
 428                         // First decode the type of this TLV:
 429                         let typ: ser::BigSize = {
 430                                 // We track whether any bytes were read during the consensus_decode call to
 431                                 // determine whether we should break or return ShortRead if we get an
 432                                 // UnexpectedEof. This should in every case be largely cosmetic, but its nice to
 433                                 // pass the TLV test vectors exactly, which require this distinction.
 434                                 let mut tracking_reader = ser::ReadTrackingReader::new(&mut stream_ref);
 435                                 match <$crate::util::ser::BigSize as $crate::util::ser::Readable>::read(&mut tracking_reader) {
 436                                         Err(DecodeError::ShortRead) => {
 437                                                 if !tracking_reader.have_read {
 438                                                         break 'tlv_read;
 439                                                 } else {
 440                                                         return Err(DecodeError::ShortRead);
 441                                                 }
 442                                         },
 443                                         Err(e) => return Err(e),
 444                                         Ok(t) => if core::ops::RangeBounds::contains(&$range, &t.0) { t } else {
 445                                                 drop(tracking_reader);
 446
 447                                                 // Assumes the type id is minimally encoded, which is enforced on read.
 448                                                 use $crate::util::ser::Writeable;
 449                                                 let bytes_read = t.serialized_length();
 450                                                 $rewind(stream_ref, bytes_read);
 451                                                 break 'tlv_read;
 452                                         },
 453                                 }
 454                         };
 455
 456                         // Types must be unique and monotonically increasing:
 457                         match last_seen_type {
 458                                 Some(t) if typ.0 <= t => {
 459                                         return Err(DecodeError::InvalidValue);
 460                                 },
 461                                 _ => {},
 462                         }
 463                         // As we read types, make sure we hit every required type between `last_seen_type` and `typ`:
 464                         $({
 465                                 $crate::_check_decoded_tlv_order!(last_seen_type, typ, $type, $field, $fieldty);
 466                         })*
 467                         last_seen_type = Some(typ.0);
 468
 469                         // Finally, read the length and value itself:
 470                         let length: ser::BigSize = $crate::util::ser::Readable::read(&mut stream_ref)?;
 471                         let mut s = ser::FixedLengthReader::new(&mut stream_ref, length.0);
 472                         match typ.0 {
 473                                 $(_t if $crate::_decode_tlv_stream_match_check!(_t, $type, $fieldty) => {
 474                                         $crate::_decode_tlv!(s, $field, $fieldty);
 475                                         if s.bytes_remain() {
 476                                                 s.eat_remaining()?; // Return ShortRead if there's actually not enough bytes
 477                                                 return Err(DecodeError::InvalidValue);
 478                                         }
 479                                 },)*
 480                                 t => {
 481                                         $(
 482                                                 if $decode_custom_tlv(t, &mut s)? {
 483                                                         // If a custom TLV was successfully read (i.e. decode_custom_tlv returns true),
 484                                                         // continue to the next TLV read.
 485                                                         s.eat_remaining()?;
 486                                                         continue 'tlv_read;
 487                                                 }
 488                                         )?
 489                                         if t % 2 == 0 {
 490                                                 return Err(DecodeError::UnknownRequiredFeature);
 491                                         }
 492                                 }
 493                         }
 494                         s.eat_remaining()?;
 495                 }
 496                 // Make sure we got to each required type after we've read every TLV:
 497                 $({
 498                         $crate::_check_missing_tlv!(last_seen_type, $type, $field, $fieldty);
 499                 })*
 500         } }
 501 }
 502
 503 /// Implements [`Readable`]/[`Writeable`] for a message struct that may include non-TLV and
 504 /// TLV-encoded parts.
 505 ///
 506 /// This is useful to implement a [`CustomMessageReader`].
 507 ///
 508 /// Currently `$fieldty` may only be `option`, i.e., `$tlvfield` is optional field.
 509 ///
 510 /// For example,
 511 /// ```
 512 /// # use lightning::impl_writeable_msg;
 513 /// struct MyCustomMessage {
 514 ///     pub field_1: u32,
 515 ///     pub field_2: bool,
 516 ///     pub field_3: String,
 517 ///     pub tlv_optional_integer: Option<u32>,
 518 /// }
 519 ///
 520 /// impl_writeable_msg!(MyCustomMessage, {
 521 ///     field_1,
 522 ///     field_2,
 523 ///     field_3
 524 /// }, {
 525 ///     (1, tlv_optional_integer, option),
 526 /// });
 527 /// ```
 528 ///
 529 /// [`Readable`]: crate::util::ser::Readable
 530 /// [`Writeable`]: crate::util::ser::Writeable
 531 /// [`CustomMessageReader`]: crate::ln::wire::CustomMessageReader
 532 #[macro_export]
 533 macro_rules! impl_writeable_msg {
 534         ($st:ident, {$($field:ident),* $(,)*}, {$(($type: expr, $tlvfield: ident, $fieldty: tt)),* $(,)*}) => {
 535                 impl $crate::util::ser::Writeable for $st {
 536                         fn write<W: $crate::util::ser::Writer>(&self, w: &mut W) -> Result<(), $crate::io::Error> {
 537                                 $( self.$field.write(w)?; )*
 538                                 $crate::encode_tlv_stream!(w, {$(($type, self.$tlvfield, $fieldty)),*});
 539                                 Ok(())
 540                         }
 541                 }
 542                 impl $crate::util::ser::Readable for $st {
 543                         fn read<R: $crate::io::Read>(r: &mut R) -> Result<Self, $crate::ln::msgs::DecodeError> {
 544                                 $(let $field = $crate::util::ser::Readable::read(r)?;)*
 545                                 $($crate::_init_tlv_field_var!($tlvfield, $fieldty);)*
 546                                 $crate::decode_tlv_stream!(r, {$(($type, $tlvfield, $fieldty)),*});
 547                                 Ok(Self {
 548                                         $($field),*,
 549                                         $($tlvfield),*
 550                                 })
 551                         }
 552                 }
 553         }
 554 }
 555
 556 macro_rules! impl_writeable {
 557         ($st:ident, {$($field:ident),*}) => {
 558                 impl $crate::util::ser::Writeable for $st {
 559                         fn write<W: $crate::util::ser::Writer>(&self, w: &mut W) -> Result<(), $crate::io::Error> {
 560                                 $( self.$field.write(w)?; )*
 561                                 Ok(())
 562                         }
 563
 564                         #[inline]
 565                         fn serialized_length(&self) -> usize {
 566                                 let mut len_calc = 0;
 567                                 $( len_calc += self.$field.serialized_length(); )*
 568                                 return len_calc;
 569                         }
 570                 }
 571
 572                 impl $crate::util::ser::Readable for $st {
 573                         fn read<R: $crate::io::Read>(r: &mut R) -> Result<Self, $crate::ln::msgs::DecodeError> {
 574                                 Ok(Self {
 575                                         $($field: $crate::util::ser::Readable::read(r)?),*
 576                                 })
 577                         }
 578                 }
 579         }
 580 }
 581
 582 /// Write out two bytes to indicate the version of an object.
 583 ///
 584 /// $this_version represents a unique version of a type. Incremented whenever the type's
 585 /// serialization format has changed or has a new interpretation. Used by a type's reader to
 586 /// determine how to interpret fields or if it can understand a serialized object.
 587 ///
 588 /// $min_version_that_can_read_this is the minimum reader version which can understand this
 589 /// serialized object. Previous versions will simply err with a [`DecodeError::UnknownVersion`].
 590 ///
 591 /// Updates to either `$this_version` or `$min_version_that_can_read_this` should be included in
 592 /// release notes.
 593 ///
 594 /// Both version fields can be specific to this type of object.
 595 ///
 596 /// [`DecodeError::UnknownVersion`]: crate::ln::msgs::DecodeError::UnknownVersion
 597 macro_rules! write_ver_prefix {
 598         ($stream: expr, $this_version: expr, $min_version_that_can_read_this: expr) => {
 599                 $stream.write_all(&[$this_version; 1])?;
 600                 $stream.write_all(&[$min_version_that_can_read_this; 1])?;
 601         }
 602 }
 603
 604 /// Writes out a suffix to an object as a length-prefixed TLV stream which contains potentially
 605 /// backwards-compatible, optional fields which old nodes can happily ignore.
 606 ///
 607 /// It is written out in TLV format and, as with all TLV fields, unknown even fields cause a
 608 /// [`DecodeError::UnknownRequiredFeature`] error, with unknown odd fields ignored.
 609 ///
 610 /// This is the preferred method of adding new fields that old nodes can ignore and still function
 611 /// correctly.
 612 ///
 613 /// [`DecodeError::UnknownRequiredFeature`]: crate::ln::msgs::DecodeError::UnknownRequiredFeature
 614 #[macro_export]
 615 macro_rules! write_tlv_fields {
 616         ($stream: expr, {$(($type: expr, $field: expr, $fieldty: tt)),* $(,)*}) => {
 617                 $crate::_encode_varint_length_prefixed_tlv!($stream, {$(($type, $field, $fieldty)),*})
 618         }
 619 }
 620
 621 /// Reads a prefix added by [`write_ver_prefix`], above. Takes the current version of the
 622 /// serialization logic for this object. This is compared against the
 623 /// `$min_version_that_can_read_this` added by [`write_ver_prefix`].
 624 macro_rules! read_ver_prefix {
 625         ($stream: expr, $this_version: expr) => { {
 626                 let ver: u8 = Readable::read($stream)?;
 627                 let min_ver: u8 = Readable::read($stream)?;
 628                 if min_ver > $this_version {
 629                         return Err(DecodeError::UnknownVersion);
 630                 }
 631                 ver
 632         } }
 633 }
 634
 635 /// Reads a suffix added by [`write_tlv_fields`].
 636 ///
 637 /// [`write_tlv_fields`]: crate::write_tlv_fields
 638 #[macro_export]
 639 macro_rules! read_tlv_fields {
 640         ($stream: expr, {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}) => { {
 641                 let tlv_len: $crate::util::ser::BigSize = $crate::util::ser::Readable::read($stream)?;
 642                 let mut rd = $crate::util::ser::FixedLengthReader::new($stream, tlv_len.0);
 643                 $crate::decode_tlv_stream!(&mut rd, {$(($type, $field, $fieldty)),*});
 644                 rd.eat_remaining().map_err(|_| $crate::ln::msgs::DecodeError::ShortRead)?;
 645         } }
 646 }
 647
 648 /// Initializes the struct fields.
 649 ///
 650 /// This is exported for use by other exported macros, do not use directly.
 651 #[doc(hidden)]
 652 #[macro_export]
 653 macro_rules! _init_tlv_based_struct_field {
 654         ($field: ident, (default_value, $default: expr)) => {
 655                 $field.0.unwrap()
 656         };
 657         ($field: ident, (static_value, $value: expr)) => {
 658                 $field
 659         };
 660         ($field: ident, option) => {
 661                 $field
 662         };
 663         ($field: ident, (option: $trait: ident $(, $read_arg: expr)?)) => {
 664                 $crate::_init_tlv_based_struct_field!($field, option)
 665         };
 666         ($field: ident, upgradable_required) => {
 667                 $field.0.unwrap()
 668         };
 669         ($field: ident, upgradable_option) => {
 670                 $field
 671         };
 672         ($field: ident, required) => {
 673                 $field.0.unwrap()
 674         };
 675         ($field: ident, vec_type) => {
 676                 $field.unwrap()
 677         };
 678 }
 679
 680 /// Initializes the variable we are going to read the TLV into.
 681 ///
 682 /// This is exported for use by other exported macros, do not use directly.
 683 #[doc(hidden)]
 684 #[macro_export]
 685 macro_rules! _init_tlv_field_var {
 686         ($field: ident, (default_value, $default: expr)) => {
 687                 let mut $field = $crate::util::ser::RequiredWrapper(None);
 688         };
 689         ($field: ident, (static_value, $value: expr)) => {
 690                 let $field;
 691         };
 692         ($field: ident, required) => {
 693                 let mut $field = $crate::util::ser::RequiredWrapper(None);
 694         };
 695         ($field: ident, (required: $trait: ident $(, $read_arg: expr)?)) => {
 696                 $crate::_init_tlv_field_var!($field, required);
 697         };
 698         ($field: ident, vec_type) => {
 699                 let mut $field = Some(Vec::new());
 700         };
 701         ($field: ident, option) => {
 702                 let mut $field = None;
 703         };
 704         ($field: ident, (option: $trait: ident $(, $read_arg: expr)?)) => {
 705                 $crate::_init_tlv_field_var!($field, option);
 706         };
 707         ($field: ident, upgradable_required) => {
 708                 let mut $field = $crate::util::ser::UpgradableRequired(None);
 709         };
 710         ($field: ident, upgradable_option) => {
 711                 let mut $field = None;
 712         };
 713 }
 714
 715 /// Equivalent to running [`_init_tlv_field_var`] then [`read_tlv_fields`].
 716 ///
 717 /// This is exported for use by other exported macros, do not use directly.
 718 #[doc(hidden)]
 719 #[macro_export]
 720 macro_rules! _init_and_read_tlv_fields {
 721         ($reader: ident, {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}) => {
 722                 $(
 723                         $crate::_init_tlv_field_var!($field, $fieldty);
 724                 )*
 725
 726                 $crate::read_tlv_fields!($reader, {
 727                         $(($type, $field, $fieldty)),*
 728                 });
 729         }
 730 }
 731
 732 /// Implements [`Readable`]/[`Writeable`] for a struct storing it as a set of TLVs
 733 /// If `$fieldty` is `required`, then `$field` is a required field that is not an [`Option`] nor a [`Vec`].
 734 /// If `$fieldty` is `(default_value, $default)`, then `$field` will be set to `$default` if not present.
 735 /// If `$fieldty` is `option`, then `$field` is optional field.
 736 /// If `$fieldty` is `vec_type`, then `$field` is a [`Vec`], which needs to have its individual elements serialized.
 737 ///
 738 /// For example,
 739 /// ```
 740 /// # use lightning::impl_writeable_tlv_based;
 741 /// struct LightningMessage {
 742 ///     tlv_integer: u32,
 743 ///     tlv_default_integer: u32,
 744 ///     tlv_optional_integer: Option<u32>,
 745 ///     tlv_vec_type_integer: Vec<u32>,
 746 /// }
 747 ///
 748 /// impl_writeable_tlv_based!(LightningMessage, {
 749 ///     (0, tlv_integer, required),
 750 ///     (1, tlv_default_integer, (default_value, 7)),
 751 ///     (2, tlv_optional_integer, option),
 752 ///     (3, tlv_vec_type_integer, vec_type),
 753 /// });
 754 /// ```
 755 ///
 756 /// [`Readable`]: crate::util::ser::Readable
 757 /// [`Writeable`]: crate::util::ser::Writeable
 758 #[macro_export]
 759 macro_rules! impl_writeable_tlv_based {
 760         ($st: ident, {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}) => {
 761                 impl $crate::util::ser::Writeable for $st {
 762                         fn write<W: $crate::util::ser::Writer>(&self, writer: &mut W) -> Result<(), $crate::io::Error> {
 763                                 $crate::write_tlv_fields!(writer, {
 764                                         $(($type, self.$field, $fieldty)),*
 765                                 });
 766                                 Ok(())
 767                         }
 768
 769                         #[inline]
 770                         fn serialized_length(&self) -> usize {
 771                                 use $crate::util::ser::BigSize;
 772                                 let len = {
 773                                         #[allow(unused_mut)]
 774                                         let mut len = $crate::util::ser::LengthCalculatingWriter(0);
 775                                         $(
 776                                                 $crate::_get_varint_length_prefixed_tlv_length!(len, $type, self.$field, $fieldty);
 777                                         )*
 778                                         len.0
 779                                 };
 780                                 let mut len_calc = $crate::util::ser::LengthCalculatingWriter(0);
 781                                 BigSize(len as u64).write(&mut len_calc).expect("No in-memory data may fail to serialize");
 782                                 len + len_calc.0
 783                         }
 784                 }
 785
 786                 impl $crate::util::ser::Readable for $st {
 787                         fn read<R: $crate::io::Read>(reader: &mut R) -> Result<Self, $crate::ln::msgs::DecodeError> {
 788                                 $crate::_init_and_read_tlv_fields!(reader, {
 789                                         $(($type, $field, $fieldty)),*
 790                                 });
 791                                 Ok(Self {
 792                                         $(
 793                                                 $field: $crate::_init_tlv_based_struct_field!($field, $fieldty)
 794                                         ),*
 795                                 })
 796                         }
 797                 }
 798         }
 799 }
 800
 801 /// Defines a struct for a TLV stream and a similar struct using references for non-primitive types,
 802 /// implementing [`Readable`] for the former and [`Writeable`] for the latter. Useful as an
 803 /// intermediary format when reading or writing a type encoded as a TLV stream. Note that each field
 804 /// representing a TLV record has its type wrapped with an [`Option`]. A tuple consisting of a type
 805 /// and a serialization wrapper may be given in place of a type when custom serialization is
 806 /// required.
 807 ///
 808 /// [`Readable`]: crate::util::ser::Readable
 809 /// [`Writeable`]: crate::util::ser::Writeable
 810 macro_rules! tlv_stream {
 811         ($name:ident, $nameref:ident, $range:expr, {
 812                 $(($type:expr, $field:ident : $fieldty:tt)),* $(,)*
 813         }) => {
 814                 #[derive(Debug)]
 815                 pub(super) struct $name {
 816                         $(
 817                                 pub(super) $field: Option<tlv_record_type!($fieldty)>,
 818                         )*
 819                 }
 820
 821                 #[cfg_attr(test, derive(PartialEq))]
 822                 #[derive(Debug)]
 823                 pub(super) struct $nameref<'a> {
 824                         $(
 825                                 pub(super) $field: Option<tlv_record_ref_type!($fieldty)>,
 826                         )*
 827                 }
 828
 829                 impl<'a> $crate::util::ser::Writeable for $nameref<'a> {
 830                         fn write<W: $crate::util::ser::Writer>(&self, writer: &mut W) -> Result<(), $crate::io::Error> {
 831                                 encode_tlv_stream!(writer, {
 832                                         $(($type, self.$field, (option, encoding: $fieldty))),*
 833                                 });
 834                                 Ok(())
 835                         }
 836                 }
 837
 838                 impl $crate::util::ser::SeekReadable for $name {
 839                         fn read<R: $crate::io::Read + $crate::io::Seek>(reader: &mut R) -> Result<Self, $crate::ln::msgs::DecodeError> {
 840                                 $(
 841                                         _init_tlv_field_var!($field, option);
 842                                 )*
 843                                 let rewind = |cursor: &mut R, offset: usize| {
 844                                         cursor.seek($crate::io::SeekFrom::Current(-(offset as i64))).expect("");
 845                                 };
 846                                 _decode_tlv_stream_range!(reader, $range, rewind, {
 847                                         $(($type, $field, (option, encoding: $fieldty))),*
 848                                 });
 849
 850                                 Ok(Self {
 851                                         $(
 852                                                 $field: $field
 853                                         ),*
 854                                 })
 855                         }
 856                 }
 857         }
 858 }
 859
 860 macro_rules! tlv_record_type {
 861         (($type:ty, $wrapper:ident)) => { $type };
 862         (($type:ty, $wrapper:ident, $encoder:ty)) => { $type };
 863         ($type:ty) => { $type };
 864 }
 865
 866 macro_rules! tlv_record_ref_type {
 867         (char) => { char };
 868         (u8) => { u8 };
 869         ((u16, $wrapper: ident)) => { u16 };
 870         ((u32, $wrapper: ident)) => { u32 };
 871         ((u64, $wrapper: ident)) => { u64 };
 872         (($type:ty, $wrapper:ident)) => { &'a $type };
 873         (($type:ty, $wrapper:ident, $encoder:ty)) => { $encoder };
 874         ($type:ty) => { &'a $type };
 875 }
 876
 877 macro_rules! _impl_writeable_tlv_based_enum_common {
 878         ($st: ident, $(($variant_id: expr, $variant_name: ident) =>
 879                 {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}
 880         ),* $(,)*;
 881         $(($tuple_variant_id: expr, $tuple_variant_name: ident)),*  $(,)*) => {
 882                 impl $crate::util::ser::Writeable for $st {
 883                         fn write<W: $crate::util::ser::Writer>(&self, writer: &mut W) -> Result<(), $crate::io::Error> {
 884                                 match self {
 885                                         $($st::$variant_name { $(ref $field),* } => {
 886                                                 let id: u8 = $variant_id;
 887                                                 id.write(writer)?;
 888                                                 write_tlv_fields!(writer, {
 889                                                         $(($type, *$field, $fieldty)),*
 890                                                 });
 891                                         }),*
 892                                         $($st::$tuple_variant_name (ref field) => {
 893                                                 let id: u8 = $tuple_variant_id;
 894                                                 id.write(writer)?;
 895                                                 field.write(writer)?;
 896                                         }),*
 897                                 }
 898                                 Ok(())
 899                         }
 900                 }
 901         }
 902 }
 903
 904 /// Implement [`Readable`] and [`Writeable`] for an enum, with struct variants stored as TLVs and tuple
 905 /// variants stored directly.
 906 /// The format is, for example
 907 /// ```ignore
 908 /// impl_writeable_tlv_based_enum!(EnumName,
 909 ///   (0, StructVariantA) => {(0, required_variant_field, required), (1, optional_variant_field, option)},
 910 ///   (1, StructVariantB) => {(0, variant_field_a, required), (1, variant_field_b, required), (2, variant_vec_field, vec_type)};
 911 ///   (2, TupleVariantA), (3, TupleVariantB),
 912 /// );
 913 /// ```
 914 /// The type is written as a single byte, followed by any variant data.
 915 /// Attempts to read an unknown type byte result in [`DecodeError::UnknownRequiredFeature`].
 916 ///
 917 /// [`Readable`]: crate::util::ser::Readable
 918 /// [`Writeable`]: crate::util::ser::Writeable
 919 /// [`DecodeError::UnknownRequiredFeature`]: crate::ln::msgs::DecodeError::UnknownRequiredFeature
 920 #[macro_export]
 921 macro_rules! impl_writeable_tlv_based_enum {
 922         ($st: ident, $(($variant_id: expr, $variant_name: ident) =>
 923                 {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}
 924         ),* $(,)*;
 925         $(($tuple_variant_id: expr, $tuple_variant_name: ident)),*  $(,)*) => {
 926                 _impl_writeable_tlv_based_enum_common!($st,
 927                         $(($variant_id, $variant_name) => {$(($type, $field, $fieldty)),*}),*;
 928                         $(($tuple_variant_id, $tuple_variant_name)),*);
 929
 930                 impl $crate::util::ser::Readable for $st {
 931                         fn read<R: $crate::io::Read>(reader: &mut R) -> Result<Self, $crate::ln::msgs::DecodeError> {
 932                                 let id: u8 = $crate::util::ser::Readable::read(reader)?;
 933                                 match id {
 934                                         $($variant_id => {
 935                                                 // Because read_tlv_fields creates a labeled loop, we cannot call it twice
 936                                                 // in the same function body. Instead, we define a closure and call it.
 937                                                 let f = || {
 938                                                         _init_and_read_tlv_fields!(reader, {
 939                                                                 $(($type, $field, $fieldty)),*
 940                                                         });
 941                                                         Ok($st::$variant_name {
 942                                                                 $(
 943                                                                         $field: _init_tlv_based_struct_field!($field, $fieldty)
 944                                                                 ),*
 945                                                         })
 946                                                 };
 947                                                 f()
 948                                         }),*
 949                                         $($tuple_variant_id => {
 950                                                 Ok($st::$tuple_variant_name(Readable::read(reader)?))
 951                                         }),*
 952                                         _ => {
 953                                                 Err($crate::ln::msgs::DecodeError::UnknownRequiredFeature)
 954                                         },
 955                                 }
 956                         }
 957                 }
 958         }
 959 }
 960
 961 /// Implement [`MaybeReadable`] and [`Writeable`] for an enum, with struct variants stored as TLVs and
 962 /// tuple variants stored directly.
 963 ///
 964 /// This is largely identical to [`impl_writeable_tlv_based_enum`], except that odd variants will
 965 /// return `Ok(None)` instead of `Err(`[`DecodeError::UnknownRequiredFeature`]`)`. It should generally be preferred
 966 /// when [`MaybeReadable`] is practical instead of just [`Readable`] as it provides an upgrade path for
 967 /// new variants to be added which are simply ignored by existing clients.
 968 ///
 969 /// [`MaybeReadable`]: crate::util::ser::MaybeReadable
 970 /// [`Writeable`]: crate::util::ser::Writeable
 971 /// [`DecodeError::UnknownRequiredFeature`]: crate::ln::msgs::DecodeError::UnknownRequiredFeature
 972 /// [`Readable`]: crate::util::ser::Readable
 973 #[macro_export]
 974 macro_rules! impl_writeable_tlv_based_enum_upgradable {
 975         ($st: ident, $(($variant_id: expr, $variant_name: ident) =>
 976                 {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}
 977         ),* $(,)*
 978         $(;
 979         $(($tuple_variant_id: expr, $tuple_variant_name: ident)),*  $(,)*)*) => {
 980                 _impl_writeable_tlv_based_enum_common!($st,
 981                         $(($variant_id, $variant_name) => {$(($type, $field, $fieldty)),*}),*;
 982                         $($(($tuple_variant_id, $tuple_variant_name)),*)*);
 983
 984                 impl $crate::util::ser::MaybeReadable for $st {
 985                         fn read<R: $crate::io::Read>(reader: &mut R) -> Result<Option<Self>, $crate::ln::msgs::DecodeError> {
 986                                 let id: u8 = $crate::util::ser::Readable::read(reader)?;
 987                                 match id {
 988                                         $($variant_id => {
 989                                                 // Because read_tlv_fields creates a labeled loop, we cannot call it twice
 990                                                 // in the same function body. Instead, we define a closure and call it.
 991                                                 let f = || {
 992                                                         _init_and_read_tlv_fields!(reader, {
 993                                                                 $(($type, $field, $fieldty)),*
 994                                                         });
 995                                                         Ok(Some($st::$variant_name {
 996                                                                 $(
 997                                                                         $field: _init_tlv_based_struct_field!($field, $fieldty)
 998                                                                 ),*
 999                                                         }))
1000                                                 };
1001                                                 f()
1002                                         }),*
1003                                         $($($tuple_variant_id => {
1004                                                 Ok(Some($st::$tuple_variant_name(Readable::read(reader)?)))
1005                                         }),*)*
1006                                         _ if id % 2 == 1 => Ok(None),
1007                                         _ => Err($crate::ln::msgs::DecodeError::UnknownRequiredFeature),
1008                                 }
1009                         }
1010                 }
1011         }
1012 }
1013
1014 #[cfg(test)]
1015 mod tests {
1016         use crate::io::{self, Cursor};
1017         use crate::prelude::*;
1018         use crate::ln::msgs::DecodeError;
1019         use crate::util::ser::{Writeable, HighZeroBytesDroppedBigSize, VecWriter};
1020         use bitcoin::secp256k1::PublicKey;
1021
1022         // The BOLT TLV test cases don't include any tests which use our "required-value" logic since
1023         // the encoding layer in the BOLTs has no such concept, though it makes our macros easier to
1024         // work with so they're baked into the decoder. Thus, we have a few additional tests below
1025         fn tlv_reader(s: &[u8]) -> Result<(u64, u32, Option<u32>), DecodeError> {
1026                 let mut s = Cursor::new(s);
1027                 let mut a: u64 = 0;
1028                 let mut b: u32 = 0;
1029                 let mut c: Option<u32> = None;
1030                 decode_tlv_stream!(&mut s, {(2, a, required), (3, b, required), (4, c, option)});
1031                 Ok((a, b, c))
1032         }
1033
1034         #[test]
1035         fn tlv_v_short_read() {
1036                 // We only expect a u32 for type 3 (which we are given), but the L says its 8 bytes.
1037                 if let Err(DecodeError::ShortRead) = tlv_reader(&::hex::decode(
1038                                 concat!("0100", "0208deadbeef1badbeef", "0308deadbeef")
1039                                 ).unwrap()[..]) {
1040                 } else { panic!(); }
1041         }
1042
1043         #[test]
1044         fn tlv_types_out_of_order() {
1045                 if let Err(DecodeError::InvalidValue) = tlv_reader(&::hex::decode(
1046                                 concat!("0100", "0304deadbeef", "0208deadbeef1badbeef")
1047                                 ).unwrap()[..]) {
1048                 } else { panic!(); }
1049                 // ...even if its some field we don't understand
1050                 if let Err(DecodeError::InvalidValue) = tlv_reader(&::hex::decode(
1051                                 concat!("0208deadbeef1badbeef", "0100", "0304deadbeef")
1052                                 ).unwrap()[..]) {
1053                 } else { panic!(); }
1054         }
1055
1056         #[test]
1057         fn tlv_req_type_missing_or_extra() {
1058                 // It's also bad if they included even fields we don't understand
1059                 if let Err(DecodeError::UnknownRequiredFeature) = tlv_reader(&::hex::decode(
1060                                 concat!("0100", "0208deadbeef1badbeef", "0304deadbeef", "0600")
1061                                 ).unwrap()[..]) {
1062                 } else { panic!(); }
1063                 // ... or if they're missing fields we need
1064                 if let Err(DecodeError::InvalidValue) = tlv_reader(&::hex::decode(
1065                                 concat!("0100", "0208deadbeef1badbeef")
1066                                 ).unwrap()[..]) {
1067                 } else { panic!(); }
1068                 // ... even if that field is even
1069                 if let Err(DecodeError::InvalidValue) = tlv_reader(&::hex::decode(
1070                                 concat!("0304deadbeef", "0500")
1071                                 ).unwrap()[..]) {
1072                 } else { panic!(); }
1073         }
1074
1075         #[test]
1076         fn tlv_simple_good_cases() {
1077                 assert_eq!(tlv_reader(&::hex::decode(
1078                                 concat!("0208deadbeef1badbeef", "03041bad1dea")
1079                                 ).unwrap()[..]).unwrap(),
1080                         (0xdeadbeef1badbeef, 0x1bad1dea, None));
1081                 assert_eq!(tlv_reader(&::hex::decode(
1082                                 concat!("0208deadbeef1badbeef", "03041bad1dea", "040401020304")
1083                                 ).unwrap()[..]).unwrap(),
1084                         (0xdeadbeef1badbeef, 0x1bad1dea, Some(0x01020304)));
1085         }
1086
1087         #[derive(Debug, PartialEq)]
1088         struct TestUpgradable {
1089                 a: u32,
1090                 b: u32,
1091                 c: Option<u32>,
1092         }
1093
1094         fn upgradable_tlv_reader(s: &[u8]) -> Result<Option<TestUpgradable>, DecodeError> {
1095                 let mut s = Cursor::new(s);
1096                 let mut a = 0;
1097                 let mut b = 0;
1098                 let mut c: Option<u32> = None;
1099                 decode_tlv_stream!(&mut s, {(2, a, upgradable_required), (3, b, upgradable_required), (4, c, upgradable_option)});
1100                 Ok(Some(TestUpgradable { a, b, c, }))
1101         }
1102
1103         #[test]
1104         fn upgradable_tlv_simple_good_cases() {
1105                 assert_eq!(upgradable_tlv_reader(&::hex::decode(
1106                         concat!("0204deadbeef", "03041bad1dea", "0404deadbeef")
1107                 ).unwrap()[..]).unwrap(),
1108                 Some(TestUpgradable { a: 0xdeadbeef, b: 0x1bad1dea, c: Some(0xdeadbeef) }));
1109
1110                 assert_eq!(upgradable_tlv_reader(&::hex::decode(
1111                         concat!("0204deadbeef", "03041bad1dea")
1112                 ).unwrap()[..]).unwrap(),
1113                 Some(TestUpgradable { a: 0xdeadbeef, b: 0x1bad1dea, c: None}));
1114         }
1115
1116         #[test]
1117         fn missing_required_upgradable() {
1118                 if let Err(DecodeError::InvalidValue) = upgradable_tlv_reader(&::hex::decode(
1119                         concat!("0100", "0204deadbeef")
1120                         ).unwrap()[..]) {
1121                 } else { panic!(); }
1122                 if let Err(DecodeError::InvalidValue) = upgradable_tlv_reader(&::hex::decode(
1123                         concat!("0100", "03041bad1dea")
1124                 ).unwrap()[..]) {
1125                 } else { panic!(); }
1126         }
1127
1128         // BOLT TLV test cases
1129         fn tlv_reader_n1(s: &[u8]) -> Result<(Option<HighZeroBytesDroppedBigSize<u64>>, Option<u64>, Option<(PublicKey, u64, u64)>, Option<u16>), DecodeError> {
1130                 let mut s = Cursor::new(s);
1131                 let mut tlv1: Option<HighZeroBytesDroppedBigSize<u64>> = None;
1132                 let mut tlv2: Option<u64> = None;
1133                 let mut tlv3: Option<(PublicKey, u64, u64)> = None;
1134                 let mut tlv4: Option<u16> = None;
1135                 decode_tlv_stream!(&mut s, {(1, tlv1, option), (2, tlv2, option), (3, tlv3, option), (254, tlv4, option)});
1136                 Ok((tlv1, tlv2, tlv3, tlv4))
1137         }
1138
1139         #[test]
1140         fn bolt_tlv_bogus_stream() {
1141                 macro_rules! do_test {
1142                         ($stream: expr, $reason: ident) => {
1143                                 if let Err(DecodeError::$reason) = tlv_reader_n1(&::hex::decode($stream).unwrap()[..]) {
1144                                 } else { panic!(); }
1145                         }
1146                 }
1147
1148                 // TLVs from the BOLT test cases which should not decode as either n1 or n2
1149                 do_test!(concat!("fd01"), ShortRead);
1150                 do_test!(concat!("fd0001", "00"), InvalidValue);
1151                 do_test!(concat!("fd0101"), ShortRead);
1152                 do_test!(concat!("0f", "fd"), ShortRead);
1153                 do_test!(concat!("0f", "fd26"), ShortRead);
1154                 do_test!(concat!("0f", "fd2602"), ShortRead);
1155                 do_test!(concat!("0f", "fd0001", "00"), InvalidValue);
1156                 do_test!(concat!("0f", "fd0201", "000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"), ShortRead);
1157
1158                 do_test!(concat!("12", "00"), UnknownRequiredFeature);
1159                 do_test!(concat!("fd0102", "00"), UnknownRequiredFeature);
1160                 do_test!(concat!("fe01000002", "00"), UnknownRequiredFeature);
1161                 do_test!(concat!("ff0100000000000002", "00"), UnknownRequiredFeature);
1162         }
1163
1164         #[test]
1165         fn bolt_tlv_bogus_n1_stream() {
1166                 macro_rules! do_test {
1167                         ($stream: expr, $reason: ident) => {
1168                                 if let Err(DecodeError::$reason) = tlv_reader_n1(&::hex::decode($stream).unwrap()[..]) {
1169                                 } else { panic!(); }
1170                         }
1171                 }
1172
1173                 // TLVs from the BOLT test cases which should not decode as n1
1174                 do_test!(concat!("01", "09", "ffffffffffffffffff"), InvalidValue);
1175                 do_test!(concat!("01", "01", "00"), InvalidValue);
1176                 do_test!(concat!("01", "02", "0001"), InvalidValue);
1177                 do_test!(concat!("01", "03", "000100"), InvalidValue);
1178                 do_test!(concat!("01", "04", "00010000"), InvalidValue);
1179                 do_test!(concat!("01", "05", "0001000000"), InvalidValue);
1180                 do_test!(concat!("01", "06", "000100000000"), InvalidValue);
1181                 do_test!(concat!("01", "07", "00010000000000"), InvalidValue);
1182                 do_test!(concat!("01", "08", "0001000000000000"), InvalidValue);
1183                 do_test!(concat!("02", "07", "01010101010101"), ShortRead);
1184                 do_test!(concat!("02", "09", "010101010101010101"), InvalidValue);
1185                 do_test!(concat!("03", "21", "023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb"), ShortRead);
1186                 do_test!(concat!("03", "29", "023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb0000000000000001"), ShortRead);
1187                 do_test!(concat!("03", "30", "023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb000000000000000100000000000001"), ShortRead);
1188                 do_test!(concat!("03", "31", "043da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb00000000000000010000000000000002"), InvalidValue);
1189                 do_test!(concat!("03", "32", "023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb0000000000000001000000000000000001"), InvalidValue);
1190                 do_test!(concat!("fd00fe", "00"), ShortRead);
1191                 do_test!(concat!("fd00fe", "01", "01"), ShortRead);
1192                 do_test!(concat!("fd00fe", "03", "010101"), InvalidValue);
1193                 do_test!(concat!("00", "00"), UnknownRequiredFeature);
1194
1195                 do_test!(concat!("02", "08", "0000000000000226", "01", "01", "2a"), InvalidValue);
1196                 do_test!(concat!("02", "08", "0000000000000231", "02", "08", "0000000000000451"), InvalidValue);
1197                 do_test!(concat!("1f", "00", "0f", "01", "2a"), InvalidValue);
1198                 do_test!(concat!("1f", "00", "1f", "01", "2a"), InvalidValue);
1199
1200                 // The last BOLT test modified to not require creating a new decoder for one trivial test.
1201                 do_test!(concat!("ffffffffffffffffff", "00", "01", "00"), InvalidValue);
1202         }
1203
1204         #[test]
1205         fn bolt_tlv_valid_n1_stream() {
1206                 macro_rules! do_test {
1207                         ($stream: expr, $tlv1: expr, $tlv2: expr, $tlv3: expr, $tlv4: expr) => {
1208                                 if let Ok((tlv1, tlv2, tlv3, tlv4)) = tlv_reader_n1(&::hex::decode($stream).unwrap()[..]) {
1209                                         assert_eq!(tlv1.map(|v| v.0), $tlv1);
1210                                         assert_eq!(tlv2, $tlv2);
1211                                         assert_eq!(tlv3, $tlv3);
1212                                         assert_eq!(tlv4, $tlv4);
1213                                 } else { panic!(); }
1214                         }
1215                 }
1216
1217                 do_test!(concat!(""), None, None, None, None);
1218                 do_test!(concat!("21", "00"), None, None, None, None);
1219                 do_test!(concat!("fd0201", "00"), None, None, None, None);
1220                 do_test!(concat!("fd00fd", "00"), None, None, None, None);
1221                 do_test!(concat!("fd00ff", "00"), None, None, None, None);
1222                 do_test!(concat!("fe02000001", "00"), None, None, None, None);
1223                 do_test!(concat!("ff0200000000000001", "00"), None, None, None, None);
1224
1225                 do_test!(concat!("01", "00"), Some(0), None, None, None);
1226                 do_test!(concat!("01", "01", "01"), Some(1), None, None, None);
1227                 do_test!(concat!("01", "02", "0100"), Some(256), None, None, None);
1228                 do_test!(concat!("01", "03", "010000"), Some(65536), None, None, None);
1229                 do_test!(concat!("01", "04", "01000000"), Some(16777216), None, None, None);
1230                 do_test!(concat!("01", "05", "0100000000"), Some(4294967296), None, None, None);
1231                 do_test!(concat!("01", "06", "010000000000"), Some(1099511627776), None, None, None);
1232                 do_test!(concat!("01", "07", "01000000000000"), Some(281474976710656), None, None, None);
1233                 do_test!(concat!("01", "08", "0100000000000000"), Some(72057594037927936), None, None, None);
1234                 do_test!(concat!("02", "08", "0000000000000226"), None, Some((0 << 30) | (0 << 5) | (550 << 0)), None, None);
1235                 do_test!(concat!("03", "31", "023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb00000000000000010000000000000002"),
1236                         None, None, Some((
1237                                 PublicKey::from_slice(&::hex::decode("023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb").unwrap()[..]).unwrap(), 1, 2)),
1238                         None);
1239                 do_test!(concat!("fd00fe", "02", "0226"), None, None, None, Some(550));
1240         }
1241
1242         fn do_simple_test_tlv_write() -> Result<(), io::Error> {
1243                 let mut stream = VecWriter(Vec::new());
1244
1245                 stream.0.clear();
1246                 _encode_varint_length_prefixed_tlv!(&mut stream, {(1, 1u8, required), (42, None::<u64>, option)});
1247                 assert_eq!(stream.0, ::hex::decode("03010101").unwrap());
1248
1249                 stream.0.clear();
1250                 _encode_varint_length_prefixed_tlv!(&mut stream, {(1, Some(1u8), option)});
1251                 assert_eq!(stream.0, ::hex::decode("03010101").unwrap());
1252
1253                 stream.0.clear();
1254                 _encode_varint_length_prefixed_tlv!(&mut stream, {(4, 0xabcdu16, required), (42, None::<u64>, option)});
1255                 assert_eq!(stream.0, ::hex::decode("040402abcd").unwrap());
1256
1257                 stream.0.clear();
1258                 _encode_varint_length_prefixed_tlv!(&mut stream, {(42, None::<u64>, option), (0xff, 0xabcdu16, required)});
1259                 assert_eq!(stream.0, ::hex::decode("06fd00ff02abcd").unwrap());
1260
1261                 stream.0.clear();
1262                 _encode_varint_length_prefixed_tlv!(&mut stream, {(0, 1u64, required), (42, None::<u64>, option), (0xff, HighZeroBytesDroppedBigSize(0u64), required)});
1263                 assert_eq!(stream.0, ::hex::decode("0e00080000000000000001fd00ff00").unwrap());
1264
1265                 stream.0.clear();
1266                 _encode_varint_length_prefixed_tlv!(&mut stream, {(0, Some(1u64), option), (0xff, HighZeroBytesDroppedBigSize(0u64), required)});
1267                 assert_eq!(stream.0, ::hex::decode("0e00080000000000000001fd00ff00").unwrap());
1268
1269                 Ok(())
1270         }
1271
1272         #[test]
1273         fn simple_test_tlv_write() {
1274                 do_simple_test_tlv_write().unwrap();
1275         }
1276 }