_ 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 // There are quite a few TLV serialization "types" which behave differently. We currently only
  17 // publicly document the `optional` and `required` types, not supporting anything else publicly and
  18 // changing them at will.
  19 //
  20 // Some of the other types include:
  21 //  * (default_value, $default) - reads optionally, reading $default if no TLV is present
  22 //  * (static_value, $value) - ignores any TLVs, always using $value
  23 //  * required_vec - reads into a Vec without a length prefix, failing if no TLV is present.
  24 //  * optional_vec - reads into an Option<Vec> without a length prefix, continuing if no TLV is
  25 //                   present. Writes from a Vec directly, only if any elements are present. Note
  26 //                   that the struct deserialization macros return a Vec, not an Option.
  27 //  * upgradable_option - reads via MaybeReadable.
  28 //  * upgradable_required - reads via MaybeReadable, requiring a TLV be present but may return None
  29 //                          if MaybeReadable::read() returns None.
  30
  31 /// Implements serialization for a single TLV record.
  32 /// This is exported for use by other exported macros, do not use directly.
  33 #[doc(hidden)]
  34 #[macro_export]
  35 macro_rules! _encode_tlv {
  36         ($stream: expr, $type: expr, $field: expr, (default_value, $default: expr)) => {
  37                 $crate::_encode_tlv!($stream, $type, $field, required)
  38         };
  39         ($stream: expr, $type: expr, $field: expr, (static_value, $value: expr)) => {
  40                 let _ = &$field; // Ensure we "use" the $field
  41         };
  42         ($stream: expr, $type: expr, $field: expr, required) => {
  43                 BigSize($type).write($stream)?;
  44                 BigSize($field.serialized_length() as u64).write($stream)?;
  45                 $field.write($stream)?;
  46         };
  47         ($stream: expr, $type: expr, $field: expr, required_vec) => {
  48                 $crate::_encode_tlv!($stream, $type, $crate::util::ser::WithoutLength(&$field), required);
  49         };
  50         ($stream: expr, $optional_type: expr, $optional_field: expr, option) => {
  51                 if let Some(ref field) = $optional_field {
  52                         BigSize($optional_type).write($stream)?;
  53                         BigSize(field.serialized_length() as u64).write($stream)?;
  54                         field.write($stream)?;
  55                 }
  56         };
  57         ($stream: expr, $type: expr, $field: expr, optional_vec) => {
  58                 if !$field.is_empty() {
  59                         $crate::_encode_tlv!($stream, $type, $field, required_vec);
  60                 }
  61         };
  62         ($stream: expr, $type: expr, $field: expr, upgradable_required) => {
  63                 $crate::_encode_tlv!($stream, $type, $field, required);
  64         };
  65         ($stream: expr, $type: expr, $field: expr, upgradable_option) => {
  66                 $crate::_encode_tlv!($stream, $type, $field, option);
  67         };
  68         ($stream: expr, $type: expr, $field: expr, (option, encoding: ($fieldty: ty, $encoding: ident))) => {
  69                 $crate::_encode_tlv!($stream, $type, $field.map(|f| $encoding(f)), option);
  70         };
  71         ($stream: expr, $type: expr, $field: expr, (option, encoding: $fieldty: ty)) => {
  72                 $crate::_encode_tlv!($stream, $type, $field, option);
  73         };
  74         ($stream: expr, $type: expr, $field: expr, (option: $trait: ident $(, $read_arg: expr)?)) => {
  75                 // Just a read-mapped type
  76                 $crate::_encode_tlv!($stream, $type, $field, option);
  77         };
  78 }
  79
  80 /// Panics if the last seen TLV type is not numerically less than the TLV type currently being checked.
  81 /// This is exported for use by other exported macros, do not use directly.
  82 #[doc(hidden)]
  83 #[macro_export]
  84 macro_rules! _check_encoded_tlv_order {
  85         ($last_type: expr, $type: expr, (static_value, $value: expr)) => { };
  86         ($last_type: expr, $type: expr, $fieldty: tt) => {
  87                 if let Some(t) = $last_type {
  88                         #[allow(unused_comparisons)] // Note that $type may be 0 making the following comparison always false
  89                         (debug_assert!(t < $type))
  90                 }
  91                 $last_type = Some($type);
  92         };
  93 }
  94
  95 /// Implements the TLVs serialization part in a [`Writeable`] implementation of a struct.
  96 ///
  97 /// This should be called inside a method which returns `Result<_, `[`io::Error`]`>`, such as
  98 /// [`Writeable::write`]. It will only return an `Err` if the stream `Err`s or [`Writeable::write`]
  99 /// on one of the fields `Err`s.
 100 ///
 101 /// `$stream` must be a `&mut `[`Writer`] which will receive the bytes for each TLV in the stream.
 102 ///
 103 /// Fields MUST be sorted in `$type`-order.
 104 ///
 105 /// Note that the lightning TLV requirements require that a single type not appear more than once,
 106 /// that TLVs are sorted in type-ascending order, and that any even types be understood by the
 107 /// decoder.
 108 ///
 109 /// Any `option` fields which have a value of `None` will not be serialized at all.
 110 ///
 111 /// For example,
 112 /// ```
 113 /// # use lightning::encode_tlv_stream;
 114 /// # fn write<W: lightning::util::ser::Writer> (stream: &mut W) -> Result<(), lightning::io::Error> {
 115 /// let mut required_value = 0u64;
 116 /// let mut optional_value: Option<u64> = None;
 117 /// encode_tlv_stream!(stream, {
 118 ///     (0, required_value, required),
 119 ///     (1, Some(42u64), option),
 120 ///     (2, optional_value, option),
 121 /// });
 122 /// // At this point `required_value` has been written as a TLV of type 0, `42u64` has been written
 123 /// // as a TLV of type 1 (indicating the reader may ignore it if it is not understood), and *no*
 124 /// // TLV is written with type 2.
 125 /// # Ok(())
 126 /// # }
 127 /// ```
 128 ///
 129 /// [`Writeable`]: crate::util::ser::Writeable
 130 /// [`io::Error`]: crate::io::Error
 131 /// [`Writeable::write`]: crate::util::ser::Writeable::write
 132 /// [`Writer`]: crate::util::ser::Writer
 133 #[macro_export]
 134 macro_rules! encode_tlv_stream {
 135         ($stream: expr, {$(($type: expr, $field: expr, $fieldty: tt)),* $(,)*}) => { {
 136                 #[allow(unused_imports)]
 137                 use $crate::{
 138                         ln::msgs::DecodeError,
 139                         util::ser,
 140                         util::ser::BigSize,
 141                         util::ser::Writeable,
 142                 };
 143
 144                 $(
 145                         $crate::_encode_tlv!($stream, $type, $field, $fieldty);
 146                 )*
 147
 148                 #[allow(unused_mut, unused_variables, unused_assignments)]
 149                 #[cfg(debug_assertions)]
 150                 {
 151                         let mut last_seen: Option<u64> = None;
 152                         $(
 153                                 $crate::_check_encoded_tlv_order!(last_seen, $type, $fieldty);
 154                         )*
 155                 }
 156         } }
 157 }
 158
 159 /// Adds the length of the serialized field to a [`LengthCalculatingWriter`].
 160 /// This is exported for use by other exported macros, do not use directly.
 161 ///
 162 /// [`LengthCalculatingWriter`]: crate::util::ser::LengthCalculatingWriter
 163 #[doc(hidden)]
 164 #[macro_export]
 165 macro_rules! _get_varint_length_prefixed_tlv_length {
 166         ($len: expr, $type: expr, $field: expr, (default_value, $default: expr)) => {
 167                 $crate::_get_varint_length_prefixed_tlv_length!($len, $type, $field, required)
 168         };
 169         ($len: expr, $type: expr, $field: expr, (static_value, $value: expr)) => {
 170         };
 171         ($len: expr, $type: expr, $field: expr, required) => {
 172                 BigSize($type).write(&mut $len).expect("No in-memory data may fail to serialize");
 173                 let field_len = $field.serialized_length();
 174                 BigSize(field_len as u64).write(&mut $len).expect("No in-memory data may fail to serialize");
 175                 $len.0 += field_len;
 176         };
 177         ($len: expr, $type: expr, $field: expr, required_vec) => {
 178                 $crate::_get_varint_length_prefixed_tlv_length!($len, $type, $crate::util::ser::WithoutLength(&$field), required);
 179         };
 180         ($len: expr, $optional_type: expr, $optional_field: expr, option) => {
 181                 if let Some(ref field) = $optional_field {
 182                         BigSize($optional_type).write(&mut $len).expect("No in-memory data may fail to serialize");
 183                         let field_len = field.serialized_length();
 184                         BigSize(field_len as u64).write(&mut $len).expect("No in-memory data may fail to serialize");
 185                         $len.0 += field_len;
 186                 }
 187         };
 188         ($len: expr, $type: expr, $field: expr, optional_vec) => {
 189                 if !$field.is_empty() {
 190                         $crate::_get_varint_length_prefixed_tlv_length!($len, $type, $field, required_vec);
 191                 }
 192         };
 193         ($len: expr, $type: expr, $field: expr, (option: $trait: ident $(, $read_arg: expr)?)) => {
 194                 $crate::_get_varint_length_prefixed_tlv_length!($len, $type, $field, option);
 195         };
 196         ($len: expr, $type: expr, $field: expr, (option, encoding: ($fieldty: ty, $encoding: ident))) => {
 197                 $crate::_get_varint_length_prefixed_tlv_length!($len, $type, $field.map(|f| $encoding(f)), option);
 198         };
 199         ($len: expr, $type: expr, $field: expr, upgradable_required) => {
 200                 $crate::_get_varint_length_prefixed_tlv_length!($len, $type, $field, required);
 201         };
 202         ($len: expr, $type: expr, $field: expr, upgradable_option) => {
 203                 $crate::_get_varint_length_prefixed_tlv_length!($len, $type, $field, option);
 204         };
 205 }
 206
 207 /// See the documentation of [`write_tlv_fields`].
 208 /// This is exported for use by other exported macros, do not use directly.
 209 #[doc(hidden)]
 210 #[macro_export]
 211 macro_rules! _encode_varint_length_prefixed_tlv {
 212         ($stream: expr, {$(($type: expr, $field: expr, $fieldty: tt)),*}) => { {
 213                 use $crate::util::ser::BigSize;
 214                 let len = {
 215                         #[allow(unused_mut)]
 216                         let mut len = $crate::util::ser::LengthCalculatingWriter(0);
 217                         $(
 218                                 $crate::_get_varint_length_prefixed_tlv_length!(len, $type, $field, $fieldty);
 219                         )*
 220                         len.0
 221                 };
 222                 BigSize(len as u64).write($stream)?;
 223                 $crate::encode_tlv_stream!($stream, { $(($type, $field, $fieldty)),* });
 224         } }
 225 }
 226
 227 /// Errors if there are missing required TLV types between the last seen type and the type currently being processed.
 228 /// This is exported for use by other exported macros, do not use directly.
 229 #[doc(hidden)]
 230 #[macro_export]
 231 macro_rules! _check_decoded_tlv_order {
 232         ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, (default_value, $default: expr)) => {{
 233                 #[allow(unused_comparisons)] // Note that $type may be 0 making the second comparison always false
 234                 let invalid_order = ($last_seen_type.is_none() || $last_seen_type.unwrap() < $type) && $typ.0 > $type;
 235                 if invalid_order {
 236                         $field = $default.into();
 237                 }
 238         }};
 239         ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, (static_value, $value: expr)) => {
 240         };
 241         ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, required) => {{
 242                 #[allow(unused_comparisons)] // Note that $type may be 0 making the second comparison always false
 243                 let invalid_order = ($last_seen_type.is_none() || $last_seen_type.unwrap() < $type) && $typ.0 > $type;
 244                 if invalid_order {
 245                         return Err(DecodeError::InvalidValue);
 246                 }
 247         }};
 248         ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, (required: $trait: ident $(, $read_arg: expr)?)) => {{
 249                 $crate::_check_decoded_tlv_order!($last_seen_type, $typ, $type, $field, required);
 250         }};
 251         ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, option) => {{
 252                 // no-op
 253         }};
 254         ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, required_vec) => {{
 255                 $crate::_check_decoded_tlv_order!($last_seen_type, $typ, $type, $field, required);
 256         }};
 257         ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, optional_vec) => {{
 258                 // no-op
 259         }};
 260         ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, upgradable_required) => {{
 261                 _check_decoded_tlv_order!($last_seen_type, $typ, $type, $field, required)
 262         }};
 263         ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, upgradable_option) => {{
 264                 // no-op
 265         }};
 266         ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, (option: $trait: ident $(, $read_arg: expr)?)) => {{
 267                 // no-op
 268         }};
 269         ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, (option, encoding: $encoding: tt)) => {{
 270                 // no-op
 271         }};
 272 }
 273
 274 /// Errors if there are missing required TLV types after the last seen type.
 275 /// This is exported for use by other exported macros, do not use directly.
 276 #[doc(hidden)]
 277 #[macro_export]
 278 macro_rules! _check_missing_tlv {
 279         ($last_seen_type: expr, $type: expr, $field: ident, (default_value, $default: expr)) => {{
 280                 #[allow(unused_comparisons)] // Note that $type may be 0 making the second comparison always false
 281                 let missing_req_type = $last_seen_type.is_none() || $last_seen_type.unwrap() < $type;
 282                 if missing_req_type {
 283                         $field = $default.into();
 284                 }
 285         }};
 286         ($last_seen_type: expr, $type: expr, $field: expr, (static_value, $value: expr)) => {
 287                 $field = $value;
 288         };
 289         ($last_seen_type: expr, $type: expr, $field: ident, required) => {{
 290                 #[allow(unused_comparisons)] // Note that $type may be 0 making the second comparison always false
 291                 let missing_req_type = $last_seen_type.is_none() || $last_seen_type.unwrap() < $type;
 292                 if missing_req_type {
 293                         return Err(DecodeError::InvalidValue);
 294                 }
 295         }};
 296         ($last_seen_type: expr, $type: expr, $field: ident, (required: $trait: ident $(, $read_arg: expr)?)) => {{
 297                 $crate::_check_missing_tlv!($last_seen_type, $type, $field, required);
 298         }};
 299         ($last_seen_type: expr, $type: expr, $field: ident, required_vec) => {{
 300                 $crate::_check_missing_tlv!($last_seen_type, $type, $field, required);
 301         }};
 302         ($last_seen_type: expr, $type: expr, $field: ident, option) => {{
 303                 // no-op
 304         }};
 305         ($last_seen_type: expr, $type: expr, $field: ident, optional_vec) => {{
 306                 // no-op
 307         }};
 308         ($last_seen_type: expr, $type: expr, $field: ident, upgradable_required) => {{
 309                 _check_missing_tlv!($last_seen_type, $type, $field, required)
 310         }};
 311         ($last_seen_type: expr, $type: expr, $field: ident, upgradable_option) => {{
 312                 // no-op
 313         }};
 314         ($last_seen_type: expr, $type: expr, $field: ident, (option: $trait: ident $(, $read_arg: expr)?)) => {{
 315                 // no-op
 316         }};
 317         ($last_seen_type: expr, $type: expr, $field: ident, (option, encoding: $encoding: tt)) => {{
 318                 // no-op
 319         }};
 320 }
 321
 322 /// Implements deserialization for a single TLV record.
 323 /// This is exported for use by other exported macros, do not use directly.
 324 #[doc(hidden)]
 325 #[macro_export]
 326 macro_rules! _decode_tlv {
 327         ($reader: expr, $field: ident, (default_value, $default: expr)) => {{
 328                 $crate::_decode_tlv!($reader, $field, required)
 329         }};
 330         ($reader: expr, $field: ident, (static_value, $value: expr)) => {{
 331         }};
 332         ($reader: expr, $field: ident, required) => {{
 333                 $field = $crate::util::ser::Readable::read(&mut $reader)?;
 334         }};
 335         ($reader: expr, $field: ident, (required: $trait: ident $(, $read_arg: expr)?)) => {{
 336                 $field = $trait::read(&mut $reader $(, $read_arg)*)?;
 337         }};
 338         ($reader: expr, $field: ident, required_vec) => {{
 339                 let f: $crate::util::ser::WithoutLength<Vec<_>> = $crate::util::ser::Readable::read(&mut $reader)?;
 340                 $field = f.0;
 341         }};
 342         ($reader: expr, $field: ident, option) => {{
 343                 $field = Some($crate::util::ser::Readable::read(&mut $reader)?);
 344         }};
 345         ($reader: expr, $field: ident, optional_vec) => {{
 346                 let f: $crate::util::ser::WithoutLength<Vec<_>> = $crate::util::ser::Readable::read(&mut $reader)?;
 347                 $field = Some(f.0);
 348         }};
 349         // `upgradable_required` indicates we're reading a required TLV that may have been upgraded
 350         // without backwards compat. We'll error if the field is missing, and return `Ok(None)` if the
 351         // field is present but we can no longer understand it.
 352         // Note that this variant can only be used within a `MaybeReadable` read.
 353         ($reader: expr, $field: ident, upgradable_required) => {{
 354                 $field = match $crate::util::ser::MaybeReadable::read(&mut $reader)? {
 355                         Some(res) => res,
 356                         _ => return Ok(None)
 357                 };
 358         }};
 359         // `upgradable_option` indicates we're reading an Option-al TLV that may have been upgraded
 360         // without backwards compat. $field will be None if the TLV is missing or if the field is present
 361         // but we can no longer understand it.
 362         ($reader: expr, $field: ident, upgradable_option) => {{
 363                 $field = $crate::util::ser::MaybeReadable::read(&mut $reader)?;
 364         }};
 365         ($reader: expr, $field: ident, (option: $trait: ident $(, $read_arg: expr)?)) => {{
 366                 $field = Some($trait::read(&mut $reader $(, $read_arg)*)?);
 367         }};
 368         ($reader: expr, $field: ident, (option, encoding: ($fieldty: ty, $encoding: ident, $encoder:ty))) => {{
 369                 $crate::_decode_tlv!($reader, $field, (option, encoding: ($fieldty, $encoding)));
 370         }};
 371         ($reader: expr, $field: ident, (option, encoding: ($fieldty: ty, $encoding: ident))) => {{
 372                 $field = {
 373                         let field: $encoding<$fieldty> = ser::Readable::read(&mut $reader)?;
 374                         Some(field.0)
 375                 };
 376         }};
 377         ($reader: expr, $field: ident, (option, encoding: $fieldty: ty)) => {{
 378                 $crate::_decode_tlv!($reader, $field, option);
 379         }};
 380 }
 381
 382 /// Checks if `$val` matches `$type`.
 383 /// This is exported for use by other exported macros, do not use directly.
 384 #[doc(hidden)]
 385 #[macro_export]
 386 macro_rules! _decode_tlv_stream_match_check {
 387         ($val: ident, $type: expr, (static_value, $value: expr)) => { false };
 388         ($val: ident, $type: expr, $fieldty: tt) => { $val == $type }
 389 }
 390
 391 /// Implements the TLVs deserialization part in a [`Readable`] implementation of a struct.
 392 ///
 393 /// This should be called inside a method which returns `Result<_, `[`DecodeError`]`>`, such as
 394 /// [`Readable::read`]. It will either return an `Err` or ensure all `required` fields have been
 395 /// read and optionally read `optional` fields.
 396 ///
 397 /// `$stream` must be a [`Read`] and will be fully consumed, reading until no more bytes remain
 398 /// (i.e. it returns [`DecodeError::ShortRead`]).
 399 ///
 400 /// Fields MUST be sorted in `$type`-order.
 401 ///
 402 /// Note that the lightning TLV requirements require that a single type not appear more than once,
 403 /// that TLVs are sorted in type-ascending order, and that any even types be understood by the
 404 /// decoder.
 405 ///
 406 /// For example,
 407 /// ```
 408 /// # use lightning::decode_tlv_stream;
 409 /// # fn read<R: lightning::io::Read> (stream: R) -> Result<(), lightning::ln::msgs::DecodeError> {
 410 /// let mut required_value = 0u64;
 411 /// let mut optional_value: Option<u64> = None;
 412 /// decode_tlv_stream!(stream, {
 413 ///     (0, required_value, required),
 414 ///     (2, optional_value, option),
 415 /// });
 416 /// // At this point, `required_value` has been overwritten with the TLV with type 0.
 417 /// // `optional_value` may have been overwritten, setting it to `Some` if a TLV with type 2 was
 418 /// // present.
 419 /// # Ok(())
 420 /// # }
 421 /// ```
 422 ///
 423 /// [`Readable`]: crate::util::ser::Readable
 424 /// [`DecodeError`]: crate::ln::msgs::DecodeError
 425 /// [`Readable::read`]: crate::util::ser::Readable::read
 426 /// [`Read`]: crate::io::Read
 427 /// [`DecodeError::ShortRead`]: crate::ln::msgs::DecodeError::ShortRead
 428 #[macro_export]
 429 macro_rules! decode_tlv_stream {
 430         ($stream: expr, {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}) => {
 431                 let rewind = |_, _| { unreachable!() };
 432                 $crate::_decode_tlv_stream_range!($stream, .., rewind, {$(($type, $field, $fieldty)),*});
 433         }
 434 }
 435
 436 /// Similar to [`decode_tlv_stream`] with a custom TLV decoding capabilities.
 437 ///
 438 /// `$decode_custom_tlv` is a closure that may be optionally provided to handle custom message types.
 439 /// If it is provided, it will be called with the custom type and the [`FixedLengthReader`] containing
 440 /// the message contents. It should return `Ok(true)` if the custom message is successfully parsed,
 441 /// `Ok(false)` if the message type is unknown, and `Err(`[`DecodeError`]`)` if parsing fails.
 442 ///
 443 /// [`FixedLengthReader`]: crate::util::ser::FixedLengthReader
 444 /// [`DecodeError`]: crate::ln::msgs::DecodeError
 445 macro_rules! decode_tlv_stream_with_custom_tlv_decode {
 446         ($stream: expr, {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}
 447          $(, $decode_custom_tlv: expr)?) => { {
 448                 let rewind = |_, _| { unreachable!() };
 449                 _decode_tlv_stream_range!(
 450                         $stream, .., rewind, {$(($type, $field, $fieldty)),*} $(, $decode_custom_tlv)?
 451                 );
 452         } }
 453 }
 454
 455 #[doc(hidden)]
 456 #[macro_export]
 457 macro_rules! _decode_tlv_stream_range {
 458         ($stream: expr, $range: expr, $rewind: ident, {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}
 459          $(, $decode_custom_tlv: expr)?) => { {
 460                 use $crate::ln::msgs::DecodeError;
 461                 let mut last_seen_type: Option<u64> = None;
 462                 let mut stream_ref = $stream;
 463                 'tlv_read: loop {
 464                         use $crate::util::ser;
 465
 466                         // First decode the type of this TLV:
 467                         let typ: ser::BigSize = {
 468                                 // We track whether any bytes were read during the consensus_decode call to
 469                                 // determine whether we should break or return ShortRead if we get an
 470                                 // UnexpectedEof. This should in every case be largely cosmetic, but its nice to
 471                                 // pass the TLV test vectors exactly, which require this distinction.
 472                                 let mut tracking_reader = ser::ReadTrackingReader::new(&mut stream_ref);
 473                                 match <$crate::util::ser::BigSize as $crate::util::ser::Readable>::read(&mut tracking_reader) {
 474                                         Err(DecodeError::ShortRead) => {
 475                                                 if !tracking_reader.have_read {
 476                                                         break 'tlv_read;
 477                                                 } else {
 478                                                         return Err(DecodeError::ShortRead);
 479                                                 }
 480                                         },
 481                                         Err(e) => return Err(e),
 482                                         Ok(t) => if core::ops::RangeBounds::contains(&$range, &t.0) { t } else {
 483                                                 drop(tracking_reader);
 484
 485                                                 // Assumes the type id is minimally encoded, which is enforced on read.
 486                                                 use $crate::util::ser::Writeable;
 487                                                 let bytes_read = t.serialized_length();
 488                                                 $rewind(stream_ref, bytes_read);
 489                                                 break 'tlv_read;
 490                                         },
 491                                 }
 492                         };
 493
 494                         // Types must be unique and monotonically increasing:
 495                         match last_seen_type {
 496                                 Some(t) if typ.0 <= t => {
 497                                         return Err(DecodeError::InvalidValue);
 498                                 },
 499                                 _ => {},
 500                         }
 501                         // As we read types, make sure we hit every required type between `last_seen_type` and `typ`:
 502                         $({
 503                                 $crate::_check_decoded_tlv_order!(last_seen_type, typ, $type, $field, $fieldty);
 504                         })*
 505                         last_seen_type = Some(typ.0);
 506
 507                         // Finally, read the length and value itself:
 508                         let length: ser::BigSize = $crate::util::ser::Readable::read(&mut stream_ref)?;
 509                         let mut s = ser::FixedLengthReader::new(&mut stream_ref, length.0);
 510                         match typ.0 {
 511                                 $(_t if $crate::_decode_tlv_stream_match_check!(_t, $type, $fieldty) => {
 512                                         $crate::_decode_tlv!(s, $field, $fieldty);
 513                                         if s.bytes_remain() {
 514                                                 s.eat_remaining()?; // Return ShortRead if there's actually not enough bytes
 515                                                 return Err(DecodeError::InvalidValue);
 516                                         }
 517                                 },)*
 518                                 t => {
 519                                         $(
 520                                                 if $decode_custom_tlv(t, &mut s)? {
 521                                                         // If a custom TLV was successfully read (i.e. decode_custom_tlv returns true),
 522                                                         // continue to the next TLV read.
 523                                                         s.eat_remaining()?;
 524                                                         continue 'tlv_read;
 525                                                 }
 526                                         )?
 527                                         if t % 2 == 0 {
 528                                                 return Err(DecodeError::UnknownRequiredFeature);
 529                                         }
 530                                 }
 531                         }
 532                         s.eat_remaining()?;
 533                 }
 534                 // Make sure we got to each required type after we've read every TLV:
 535                 $({
 536                         $crate::_check_missing_tlv!(last_seen_type, $type, $field, $fieldty);
 537                 })*
 538         } }
 539 }
 540
 541 /// Implements [`Readable`]/[`Writeable`] for a message struct that may include non-TLV and
 542 /// TLV-encoded parts.
 543 ///
 544 /// This is useful to implement a [`CustomMessageReader`].
 545 ///
 546 /// Currently `$fieldty` may only be `option`, i.e., `$tlvfield` is optional field.
 547 ///
 548 /// For example,
 549 /// ```
 550 /// # use lightning::impl_writeable_msg;
 551 /// struct MyCustomMessage {
 552 ///     pub field_1: u32,
 553 ///     pub field_2: bool,
 554 ///     pub field_3: String,
 555 ///     pub tlv_optional_integer: Option<u32>,
 556 /// }
 557 ///
 558 /// impl_writeable_msg!(MyCustomMessage, {
 559 ///     field_1,
 560 ///     field_2,
 561 ///     field_3
 562 /// }, {
 563 ///     (1, tlv_optional_integer, option),
 564 /// });
 565 /// ```
 566 ///
 567 /// [`Readable`]: crate::util::ser::Readable
 568 /// [`Writeable`]: crate::util::ser::Writeable
 569 /// [`CustomMessageReader`]: crate::ln::wire::CustomMessageReader
 570 #[macro_export]
 571 macro_rules! impl_writeable_msg {
 572         ($st:ident, {$($field:ident),* $(,)*}, {$(($type: expr, $tlvfield: ident, $fieldty: tt)),* $(,)*}) => {
 573                 impl $crate::util::ser::Writeable for $st {
 574                         fn write<W: $crate::util::ser::Writer>(&self, w: &mut W) -> Result<(), $crate::io::Error> {
 575                                 $( self.$field.write(w)?; )*
 576                                 $crate::encode_tlv_stream!(w, {$(($type, self.$tlvfield.as_ref(), $fieldty)),*});
 577                                 Ok(())
 578                         }
 579                 }
 580                 impl $crate::util::ser::Readable for $st {
 581                         fn read<R: $crate::io::Read>(r: &mut R) -> Result<Self, $crate::ln::msgs::DecodeError> {
 582                                 $(let $field = $crate::util::ser::Readable::read(r)?;)*
 583                                 $($crate::_init_tlv_field_var!($tlvfield, $fieldty);)*
 584                                 $crate::decode_tlv_stream!(r, {$(($type, $tlvfield, $fieldty)),*});
 585                                 Ok(Self {
 586                                         $($field),*,
 587                                         $($tlvfield),*
 588                                 })
 589                         }
 590                 }
 591         }
 592 }
 593
 594 macro_rules! impl_writeable {
 595         ($st:ident, {$($field:ident),*}) => {
 596                 impl $crate::util::ser::Writeable for $st {
 597                         fn write<W: $crate::util::ser::Writer>(&self, w: &mut W) -> Result<(), $crate::io::Error> {
 598                                 $( self.$field.write(w)?; )*
 599                                 Ok(())
 600                         }
 601
 602                         #[inline]
 603                         fn serialized_length(&self) -> usize {
 604                                 let mut len_calc = 0;
 605                                 $( len_calc += self.$field.serialized_length(); )*
 606                                 return len_calc;
 607                         }
 608                 }
 609
 610                 impl $crate::util::ser::Readable for $st {
 611                         fn read<R: $crate::io::Read>(r: &mut R) -> Result<Self, $crate::ln::msgs::DecodeError> {
 612                                 Ok(Self {
 613                                         $($field: $crate::util::ser::Readable::read(r)?),*
 614                                 })
 615                         }
 616                 }
 617         }
 618 }
 619
 620 /// Write out two bytes to indicate the version of an object.
 621 ///
 622 /// $this_version represents a unique version of a type. Incremented whenever the type's
 623 /// serialization format has changed or has a new interpretation. Used by a type's reader to
 624 /// determine how to interpret fields or if it can understand a serialized object.
 625 ///
 626 /// $min_version_that_can_read_this is the minimum reader version which can understand this
 627 /// serialized object. Previous versions will simply err with a [`DecodeError::UnknownVersion`].
 628 ///
 629 /// Updates to either `$this_version` or `$min_version_that_can_read_this` should be included in
 630 /// release notes.
 631 ///
 632 /// Both version fields can be specific to this type of object.
 633 ///
 634 /// [`DecodeError::UnknownVersion`]: crate::ln::msgs::DecodeError::UnknownVersion
 635 macro_rules! write_ver_prefix {
 636         ($stream: expr, $this_version: expr, $min_version_that_can_read_this: expr) => {
 637                 $stream.write_all(&[$this_version; 1])?;
 638                 $stream.write_all(&[$min_version_that_can_read_this; 1])?;
 639         }
 640 }
 641
 642 /// Writes out a suffix to an object as a length-prefixed TLV stream which contains potentially
 643 /// backwards-compatible, optional fields which old nodes can happily ignore.
 644 ///
 645 /// It is written out in TLV format and, as with all TLV fields, unknown even fields cause a
 646 /// [`DecodeError::UnknownRequiredFeature`] error, with unknown odd fields ignored.
 647 ///
 648 /// This is the preferred method of adding new fields that old nodes can ignore and still function
 649 /// correctly.
 650 ///
 651 /// [`DecodeError::UnknownRequiredFeature`]: crate::ln::msgs::DecodeError::UnknownRequiredFeature
 652 #[macro_export]
 653 macro_rules! write_tlv_fields {
 654         ($stream: expr, {$(($type: expr, $field: expr, $fieldty: tt)),* $(,)*}) => {
 655                 $crate::_encode_varint_length_prefixed_tlv!($stream, {$(($type, $field, $fieldty)),*})
 656         }
 657 }
 658
 659 /// Reads a prefix added by [`write_ver_prefix`], above. Takes the current version of the
 660 /// serialization logic for this object. This is compared against the
 661 /// `$min_version_that_can_read_this` added by [`write_ver_prefix`].
 662 macro_rules! read_ver_prefix {
 663         ($stream: expr, $this_version: expr) => { {
 664                 let ver: u8 = Readable::read($stream)?;
 665                 let min_ver: u8 = Readable::read($stream)?;
 666                 if min_ver > $this_version {
 667                         return Err(DecodeError::UnknownVersion);
 668                 }
 669                 ver
 670         } }
 671 }
 672
 673 /// Reads a suffix added by [`write_tlv_fields`].
 674 ///
 675 /// [`write_tlv_fields`]: crate::write_tlv_fields
 676 #[macro_export]
 677 macro_rules! read_tlv_fields {
 678         ($stream: expr, {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}) => { {
 679                 let tlv_len: $crate::util::ser::BigSize = $crate::util::ser::Readable::read($stream)?;
 680                 let mut rd = $crate::util::ser::FixedLengthReader::new($stream, tlv_len.0);
 681                 $crate::decode_tlv_stream!(&mut rd, {$(($type, $field, $fieldty)),*});
 682                 rd.eat_remaining().map_err(|_| $crate::ln::msgs::DecodeError::ShortRead)?;
 683         } }
 684 }
 685
 686 /// Initializes the struct fields.
 687 ///
 688 /// This is exported for use by other exported macros, do not use directly.
 689 #[doc(hidden)]
 690 #[macro_export]
 691 macro_rules! _init_tlv_based_struct_field {
 692         ($field: ident, (default_value, $default: expr)) => {
 693                 $field.0.unwrap()
 694         };
 695         ($field: ident, (static_value, $value: expr)) => {
 696                 $field
 697         };
 698         ($field: ident, option) => {
 699                 $field
 700         };
 701         ($field: ident, (option: $trait: ident $(, $read_arg: expr)?)) => {
 702                 $crate::_init_tlv_based_struct_field!($field, option)
 703         };
 704         ($field: ident, upgradable_required) => {
 705                 $field.0.unwrap()
 706         };
 707         ($field: ident, upgradable_option) => {
 708                 $field
 709         };
 710         ($field: ident, required) => {
 711                 $field.0.unwrap()
 712         };
 713         ($field: ident, required_vec) => {
 714                 $field
 715         };
 716         ($field: ident, optional_vec) => {
 717                 $field.unwrap()
 718         };
 719 }
 720
 721 /// Initializes the variable we are going to read the TLV into.
 722 ///
 723 /// This is exported for use by other exported macros, do not use directly.
 724 #[doc(hidden)]
 725 #[macro_export]
 726 macro_rules! _init_tlv_field_var {
 727         ($field: ident, (default_value, $default: expr)) => {
 728                 let mut $field = $crate::util::ser::RequiredWrapper(None);
 729         };
 730         ($field: ident, (static_value, $value: expr)) => {
 731                 let $field;
 732         };
 733         ($field: ident, required) => {
 734                 let mut $field = $crate::util::ser::RequiredWrapper(None);
 735         };
 736         ($field: ident, (required: $trait: ident $(, $read_arg: expr)?)) => {
 737                 $crate::_init_tlv_field_var!($field, required);
 738         };
 739         ($field: ident, required_vec) => {
 740                 let mut $field = Vec::new();
 741         };
 742         ($field: ident, option) => {
 743                 let mut $field = None;
 744         };
 745         ($field: ident, optional_vec) => {
 746                 let mut $field = Some(Vec::new());
 747         };
 748         ($field: ident, (option, encoding: ($fieldty: ty, $encoding: ident))) => {
 749                 $crate::_init_tlv_field_var!($field, option);
 750         };
 751         ($field: ident, (option: $trait: ident $(, $read_arg: expr)?)) => {
 752                 $crate::_init_tlv_field_var!($field, option);
 753         };
 754         ($field: ident, upgradable_required) => {
 755                 let mut $field = $crate::util::ser::UpgradableRequired(None);
 756         };
 757         ($field: ident, upgradable_option) => {
 758                 let mut $field = None;
 759         };
 760 }
 761
 762 /// Equivalent to running [`_init_tlv_field_var`] then [`read_tlv_fields`].
 763 ///
 764 /// This is exported for use by other exported macros, do not use directly.
 765 #[doc(hidden)]
 766 #[macro_export]
 767 macro_rules! _init_and_read_tlv_fields {
 768         ($reader: ident, {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}) => {
 769                 $(
 770                         $crate::_init_tlv_field_var!($field, $fieldty);
 771                 )*
 772
 773                 $crate::read_tlv_fields!($reader, {
 774                         $(($type, $field, $fieldty)),*
 775                 });
 776         }
 777 }
 778
 779 /// Implements [`Readable`]/[`Writeable`] for a struct storing it as a set of TLVs
 780 /// If `$fieldty` is `required`, then `$field` is a required field that is not an [`Option`] nor a [`Vec`].
 781 /// If `$fieldty` is `(default_value, $default)`, then `$field` will be set to `$default` if not present.
 782 /// If `$fieldty` is `option`, then `$field` is optional field.
 783 /// If `$fieldty` is `optional_vec`, then `$field` is a [`Vec`], which needs to have its individual elements serialized.
 784 ///    Note that for `optional_vec` no bytes are written if the vec is empty
 785 ///
 786 /// For example,
 787 /// ```
 788 /// # use lightning::impl_writeable_tlv_based;
 789 /// struct LightningMessage {
 790 ///     tlv_integer: u32,
 791 ///     tlv_default_integer: u32,
 792 ///     tlv_optional_integer: Option<u32>,
 793 ///     tlv_vec_type_integer: Vec<u32>,
 794 /// }
 795 ///
 796 /// impl_writeable_tlv_based!(LightningMessage, {
 797 ///     (0, tlv_integer, required),
 798 ///     (1, tlv_default_integer, (default_value, 7)),
 799 ///     (2, tlv_optional_integer, option),
 800 ///     (3, tlv_vec_type_integer, optional_vec),
 801 /// });
 802 /// ```
 803 ///
 804 /// [`Readable`]: crate::util::ser::Readable
 805 /// [`Writeable`]: crate::util::ser::Writeable
 806 #[macro_export]
 807 macro_rules! impl_writeable_tlv_based {
 808         ($st: ident, {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}) => {
 809                 impl $crate::util::ser::Writeable for $st {
 810                         fn write<W: $crate::util::ser::Writer>(&self, writer: &mut W) -> Result<(), $crate::io::Error> {
 811                                 $crate::write_tlv_fields!(writer, {
 812                                         $(($type, self.$field, $fieldty)),*
 813                                 });
 814                                 Ok(())
 815                         }
 816
 817                         #[inline]
 818                         fn serialized_length(&self) -> usize {
 819                                 use $crate::util::ser::BigSize;
 820                                 let len = {
 821                                         #[allow(unused_mut)]
 822                                         let mut len = $crate::util::ser::LengthCalculatingWriter(0);
 823                                         $(
 824                                                 $crate::_get_varint_length_prefixed_tlv_length!(len, $type, self.$field, $fieldty);
 825                                         )*
 826                                         len.0
 827                                 };
 828                                 let mut len_calc = $crate::util::ser::LengthCalculatingWriter(0);
 829                                 BigSize(len as u64).write(&mut len_calc).expect("No in-memory data may fail to serialize");
 830                                 len + len_calc.0
 831                         }
 832                 }
 833
 834                 impl $crate::util::ser::Readable for $st {
 835                         fn read<R: $crate::io::Read>(reader: &mut R) -> Result<Self, $crate::ln::msgs::DecodeError> {
 836                                 $crate::_init_and_read_tlv_fields!(reader, {
 837                                         $(($type, $field, $fieldty)),*
 838                                 });
 839                                 Ok(Self {
 840                                         $(
 841                                                 $field: $crate::_init_tlv_based_struct_field!($field, $fieldty)
 842                                         ),*
 843                                 })
 844                         }
 845                 }
 846         }
 847 }
 848
 849 /// Defines a struct for a TLV stream and a similar struct using references for non-primitive types,
 850 /// implementing [`Readable`] for the former and [`Writeable`] for the latter. Useful as an
 851 /// intermediary format when reading or writing a type encoded as a TLV stream. Note that each field
 852 /// representing a TLV record has its type wrapped with an [`Option`]. A tuple consisting of a type
 853 /// and a serialization wrapper may be given in place of a type when custom serialization is
 854 /// required.
 855 ///
 856 /// [`Readable`]: crate::util::ser::Readable
 857 /// [`Writeable`]: crate::util::ser::Writeable
 858 macro_rules! tlv_stream {
 859         ($name:ident, $nameref:ident, $range:expr, {
 860                 $(($type:expr, $field:ident : $fieldty:tt)),* $(,)*
 861         }) => {
 862                 #[derive(Debug)]
 863                 pub(super) struct $name {
 864                         $(
 865                                 pub(super) $field: Option<tlv_record_type!($fieldty)>,
 866                         )*
 867                 }
 868
 869                 #[cfg_attr(test, derive(PartialEq))]
 870                 #[derive(Debug)]
 871                 pub(super) struct $nameref<'a> {
 872                         $(
 873                                 pub(super) $field: Option<tlv_record_ref_type!($fieldty)>,
 874                         )*
 875                 }
 876
 877                 impl<'a> $crate::util::ser::Writeable for $nameref<'a> {
 878                         fn write<W: $crate::util::ser::Writer>(&self, writer: &mut W) -> Result<(), $crate::io::Error> {
 879                                 encode_tlv_stream!(writer, {
 880                                         $(($type, self.$field, (option, encoding: $fieldty))),*
 881                                 });
 882                                 Ok(())
 883                         }
 884                 }
 885
 886                 impl $crate::util::ser::SeekReadable for $name {
 887                         fn read<R: $crate::io::Read + $crate::io::Seek>(reader: &mut R) -> Result<Self, $crate::ln::msgs::DecodeError> {
 888                                 $(
 889                                         _init_tlv_field_var!($field, option);
 890                                 )*
 891                                 let rewind = |cursor: &mut R, offset: usize| {
 892                                         cursor.seek($crate::io::SeekFrom::Current(-(offset as i64))).expect("");
 893                                 };
 894                                 _decode_tlv_stream_range!(reader, $range, rewind, {
 895                                         $(($type, $field, (option, encoding: $fieldty))),*
 896                                 });
 897
 898                                 Ok(Self {
 899                                         $(
 900                                                 $field: $field
 901                                         ),*
 902                                 })
 903                         }
 904                 }
 905         }
 906 }
 907
 908 macro_rules! tlv_record_type {
 909         (($type:ty, $wrapper:ident)) => { $type };
 910         (($type:ty, $wrapper:ident, $encoder:ty)) => { $type };
 911         ($type:ty) => { $type };
 912 }
 913
 914 macro_rules! tlv_record_ref_type {
 915         (char) => { char };
 916         (u8) => { u8 };
 917         ((u16, $wrapper: ident)) => { u16 };
 918         ((u32, $wrapper: ident)) => { u32 };
 919         ((u64, $wrapper: ident)) => { u64 };
 920         (($type:ty, $wrapper:ident)) => { &'a $type };
 921         (($type:ty, $wrapper:ident, $encoder:ty)) => { $encoder };
 922         ($type:ty) => { &'a $type };
 923 }
 924
 925 #[doc(hidden)]
 926 #[macro_export]
 927 macro_rules! _impl_writeable_tlv_based_enum_common {
 928         ($st: ident, $(($variant_id: expr, $variant_name: ident) =>
 929                 {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}
 930         ),* $(,)*;
 931         $(($tuple_variant_id: expr, $tuple_variant_name: ident)),*  $(,)*) => {
 932                 impl $crate::util::ser::Writeable for $st {
 933                         fn write<W: $crate::util::ser::Writer>(&self, writer: &mut W) -> Result<(), $crate::io::Error> {
 934                                 match self {
 935                                         $($st::$variant_name { $(ref $field),* } => {
 936                                                 let id: u8 = $variant_id;
 937                                                 id.write(writer)?;
 938                                                 $crate::write_tlv_fields!(writer, {
 939                                                         $(($type, *$field, $fieldty)),*
 940                                                 });
 941                                         }),*
 942                                         $($st::$tuple_variant_name (ref field) => {
 943                                                 let id: u8 = $tuple_variant_id;
 944                                                 id.write(writer)?;
 945                                                 field.write(writer)?;
 946                                         }),*
 947                                 }
 948                                 Ok(())
 949                         }
 950                 }
 951         }
 952 }
 953
 954 /// Implement [`Readable`] and [`Writeable`] for an enum, with struct variants stored as TLVs and tuple
 955 /// variants stored directly.
 956 /// The format is, for example
 957 /// ```ignore
 958 /// impl_writeable_tlv_based_enum!(EnumName,
 959 ///   (0, StructVariantA) => {(0, required_variant_field, required), (1, optional_variant_field, option)},
 960 ///   (1, StructVariantB) => {(0, variant_field_a, required), (1, variant_field_b, required), (2, variant_vec_field, optional_vec)};
 961 ///   (2, TupleVariantA), (3, TupleVariantB),
 962 /// );
 963 /// ```
 964 /// The type is written as a single byte, followed by any variant data.
 965 /// Attempts to read an unknown type byte result in [`DecodeError::UnknownRequiredFeature`].
 966 ///
 967 /// [`Readable`]: crate::util::ser::Readable
 968 /// [`Writeable`]: crate::util::ser::Writeable
 969 /// [`DecodeError::UnknownRequiredFeature`]: crate::ln::msgs::DecodeError::UnknownRequiredFeature
 970 #[macro_export]
 971 macro_rules! impl_writeable_tlv_based_enum {
 972         ($st: ident, $(($variant_id: expr, $variant_name: ident) =>
 973                 {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}
 974         ),* $(,)*;
 975         $(($tuple_variant_id: expr, $tuple_variant_name: ident)),*  $(,)*) => {
 976                 $crate::_impl_writeable_tlv_based_enum_common!($st,
 977                         $(($variant_id, $variant_name) => {$(($type, $field, $fieldty)),*}),*;
 978                         $(($tuple_variant_id, $tuple_variant_name)),*);
 979
 980                 impl $crate::util::ser::Readable for $st {
 981                         fn read<R: $crate::io::Read>(reader: &mut R) -> Result<Self, $crate::ln::msgs::DecodeError> {
 982                                 let id: u8 = $crate::util::ser::Readable::read(reader)?;
 983                                 match id {
 984                                         $($variant_id => {
 985                                                 // Because read_tlv_fields creates a labeled loop, we cannot call it twice
 986                                                 // in the same function body. Instead, we define a closure and call it.
 987                                                 let f = || {
 988                                                         $crate::_init_and_read_tlv_fields!(reader, {
 989                                                                 $(($type, $field, $fieldty)),*
 990                                                         });
 991                                                         Ok($st::$variant_name {
 992                                                                 $(
 993                                                                         $field: $crate::_init_tlv_based_struct_field!($field, $fieldty)
 994                                                                 ),*
 995                                                         })
 996                                                 };
 997                                                 f()
 998                                         }),*
 999                                         $($tuple_variant_id => {
1000                                                 Ok($st::$tuple_variant_name($crate::util::ser::Readable::read(reader)?))
1001                                         }),*
1002                                         _ => {
1003                                                 Err($crate::ln::msgs::DecodeError::UnknownRequiredFeature)
1004                                         },
1005                                 }
1006                         }
1007                 }
1008         }
1009 }
1010
1011 /// Implement [`MaybeReadable`] and [`Writeable`] for an enum, with struct variants stored as TLVs and
1012 /// tuple variants stored directly.
1013 ///
1014 /// This is largely identical to [`impl_writeable_tlv_based_enum`], except that odd variants will
1015 /// return `Ok(None)` instead of `Err(`[`DecodeError::UnknownRequiredFeature`]`)`. It should generally be preferred
1016 /// when [`MaybeReadable`] is practical instead of just [`Readable`] as it provides an upgrade path for
1017 /// new variants to be added which are simply ignored by existing clients.
1018 ///
1019 /// [`MaybeReadable`]: crate::util::ser::MaybeReadable
1020 /// [`Writeable`]: crate::util::ser::Writeable
1021 /// [`DecodeError::UnknownRequiredFeature`]: crate::ln::msgs::DecodeError::UnknownRequiredFeature
1022 /// [`Readable`]: crate::util::ser::Readable
1023 #[macro_export]
1024 macro_rules! impl_writeable_tlv_based_enum_upgradable {
1025         ($st: ident, $(($variant_id: expr, $variant_name: ident) =>
1026                 {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}
1027         ),* $(,)*
1028         $(;
1029         $(($tuple_variant_id: expr, $tuple_variant_name: ident)),*  $(,)*)*) => {
1030                 $crate::_impl_writeable_tlv_based_enum_common!($st,
1031                         $(($variant_id, $variant_name) => {$(($type, $field, $fieldty)),*}),*;
1032                         $($(($tuple_variant_id, $tuple_variant_name)),*)*);
1033
1034                 impl $crate::util::ser::MaybeReadable for $st {
1035                         fn read<R: $crate::io::Read>(reader: &mut R) -> Result<Option<Self>, $crate::ln::msgs::DecodeError> {
1036                                 let id: u8 = $crate::util::ser::Readable::read(reader)?;
1037                                 match id {
1038                                         $($variant_id => {
1039                                                 // Because read_tlv_fields creates a labeled loop, we cannot call it twice
1040                                                 // in the same function body. Instead, we define a closure and call it.
1041                                                 let f = || {
1042                                                         $crate::_init_and_read_tlv_fields!(reader, {
1043                                                                 $(($type, $field, $fieldty)),*
1044                                                         });
1045                                                         Ok(Some($st::$variant_name {
1046                                                                 $(
1047                                                                         $field: $crate::_init_tlv_based_struct_field!($field, $fieldty)
1048                                                                 ),*
1049                                                         }))
1050                                                 };
1051                                                 f()
1052                                         }),*
1053                                         $($($tuple_variant_id => {
1054                                                 Ok(Some($st::$tuple_variant_name(Readable::read(reader)?)))
1055                                         }),*)*
1056                                         _ if id % 2 == 1 => Ok(None),
1057                                         _ => Err($crate::ln::msgs::DecodeError::UnknownRequiredFeature),
1058                                 }
1059                         }
1060                 }
1061         }
1062 }
1063
1064 #[cfg(test)]
1065 mod tests {
1066         use crate::io::{self, Cursor};
1067         use crate::prelude::*;
1068         use crate::ln::msgs::DecodeError;
1069         use crate::util::ser::{Writeable, HighZeroBytesDroppedBigSize, VecWriter};
1070         use bitcoin::secp256k1::PublicKey;
1071
1072         // The BOLT TLV test cases don't include any tests which use our "required-value" logic since
1073         // the encoding layer in the BOLTs has no such concept, though it makes our macros easier to
1074         // work with so they're baked into the decoder. Thus, we have a few additional tests below
1075         fn tlv_reader(s: &[u8]) -> Result<(u64, u32, Option<u32>), DecodeError> {
1076                 let mut s = Cursor::new(s);
1077                 let mut a: u64 = 0;
1078                 let mut b: u32 = 0;
1079                 let mut c: Option<u32> = None;
1080                 decode_tlv_stream!(&mut s, {(2, a, required), (3, b, required), (4, c, option)});
1081                 Ok((a, b, c))
1082         }
1083
1084         #[test]
1085         fn tlv_v_short_read() {
1086                 // We only expect a u32 for type 3 (which we are given), but the L says its 8 bytes.
1087                 if let Err(DecodeError::ShortRead) = tlv_reader(&::hex::decode(
1088                                 concat!("0100", "0208deadbeef1badbeef", "0308deadbeef")
1089                                 ).unwrap()[..]) {
1090                 } else { panic!(); }
1091         }
1092
1093         #[test]
1094         fn tlv_types_out_of_order() {
1095                 if let Err(DecodeError::InvalidValue) = tlv_reader(&::hex::decode(
1096                                 concat!("0100", "0304deadbeef", "0208deadbeef1badbeef")
1097                                 ).unwrap()[..]) {
1098                 } else { panic!(); }
1099                 // ...even if its some field we don't understand
1100                 if let Err(DecodeError::InvalidValue) = tlv_reader(&::hex::decode(
1101                                 concat!("0208deadbeef1badbeef", "0100", "0304deadbeef")
1102                                 ).unwrap()[..]) {
1103                 } else { panic!(); }
1104         }
1105
1106         #[test]
1107         fn tlv_req_type_missing_or_extra() {
1108                 // It's also bad if they included even fields we don't understand
1109                 if let Err(DecodeError::UnknownRequiredFeature) = tlv_reader(&::hex::decode(
1110                                 concat!("0100", "0208deadbeef1badbeef", "0304deadbeef", "0600")
1111                                 ).unwrap()[..]) {
1112                 } else { panic!(); }
1113                 // ... or if they're missing fields we need
1114                 if let Err(DecodeError::InvalidValue) = tlv_reader(&::hex::decode(
1115                                 concat!("0100", "0208deadbeef1badbeef")
1116                                 ).unwrap()[..]) {
1117                 } else { panic!(); }
1118                 // ... even if that field is even
1119                 if let Err(DecodeError::InvalidValue) = tlv_reader(&::hex::decode(
1120                                 concat!("0304deadbeef", "0500")
1121                                 ).unwrap()[..]) {
1122                 } else { panic!(); }
1123         }
1124
1125         #[test]
1126         fn tlv_simple_good_cases() {
1127                 assert_eq!(tlv_reader(&::hex::decode(
1128                                 concat!("0208deadbeef1badbeef", "03041bad1dea")
1129                                 ).unwrap()[..]).unwrap(),
1130                         (0xdeadbeef1badbeef, 0x1bad1dea, None));
1131                 assert_eq!(tlv_reader(&::hex::decode(
1132                                 concat!("0208deadbeef1badbeef", "03041bad1dea", "040401020304")
1133                                 ).unwrap()[..]).unwrap(),
1134                         (0xdeadbeef1badbeef, 0x1bad1dea, Some(0x01020304)));
1135         }
1136
1137         #[derive(Debug, PartialEq)]
1138         struct TestUpgradable {
1139                 a: u32,
1140                 b: u32,
1141                 c: Option<u32>,
1142         }
1143
1144         fn upgradable_tlv_reader(s: &[u8]) -> Result<Option<TestUpgradable>, DecodeError> {
1145                 let mut s = Cursor::new(s);
1146                 let mut a = 0;
1147                 let mut b = 0;
1148                 let mut c: Option<u32> = None;
1149                 decode_tlv_stream!(&mut s, {(2, a, upgradable_required), (3, b, upgradable_required), (4, c, upgradable_option)});
1150                 Ok(Some(TestUpgradable { a, b, c, }))
1151         }
1152
1153         #[test]
1154         fn upgradable_tlv_simple_good_cases() {
1155                 assert_eq!(upgradable_tlv_reader(&::hex::decode(
1156                         concat!("0204deadbeef", "03041bad1dea", "0404deadbeef")
1157                 ).unwrap()[..]).unwrap(),
1158                 Some(TestUpgradable { a: 0xdeadbeef, b: 0x1bad1dea, c: Some(0xdeadbeef) }));
1159
1160                 assert_eq!(upgradable_tlv_reader(&::hex::decode(
1161                         concat!("0204deadbeef", "03041bad1dea")
1162                 ).unwrap()[..]).unwrap(),
1163                 Some(TestUpgradable { a: 0xdeadbeef, b: 0x1bad1dea, c: None}));
1164         }
1165
1166         #[test]
1167         fn missing_required_upgradable() {
1168                 if let Err(DecodeError::InvalidValue) = upgradable_tlv_reader(&::hex::decode(
1169                         concat!("0100", "0204deadbeef")
1170                         ).unwrap()[..]) {
1171                 } else { panic!(); }
1172                 if let Err(DecodeError::InvalidValue) = upgradable_tlv_reader(&::hex::decode(
1173                         concat!("0100", "03041bad1dea")
1174                 ).unwrap()[..]) {
1175                 } else { panic!(); }
1176         }
1177
1178         // BOLT TLV test cases
1179         fn tlv_reader_n1(s: &[u8]) -> Result<(Option<HighZeroBytesDroppedBigSize<u64>>, Option<u64>, Option<(PublicKey, u64, u64)>, Option<u16>), DecodeError> {
1180                 let mut s = Cursor::new(s);
1181                 let mut tlv1: Option<HighZeroBytesDroppedBigSize<u64>> = None;
1182                 let mut tlv2: Option<u64> = None;
1183                 let mut tlv3: Option<(PublicKey, u64, u64)> = None;
1184                 let mut tlv4: Option<u16> = None;
1185                 decode_tlv_stream!(&mut s, {(1, tlv1, option), (2, tlv2, option), (3, tlv3, option), (254, tlv4, option)});
1186                 Ok((tlv1, tlv2, tlv3, tlv4))
1187         }
1188
1189         #[test]
1190         fn bolt_tlv_bogus_stream() {
1191                 macro_rules! do_test {
1192                         ($stream: expr, $reason: ident) => {
1193                                 if let Err(DecodeError::$reason) = tlv_reader_n1(&::hex::decode($stream).unwrap()[..]) {
1194                                 } else { panic!(); }
1195                         }
1196                 }
1197
1198                 // TLVs from the BOLT test cases which should not decode as either n1 or n2
1199                 do_test!(concat!("fd01"), ShortRead);
1200                 do_test!(concat!("fd0001", "00"), InvalidValue);
1201                 do_test!(concat!("fd0101"), ShortRead);
1202                 do_test!(concat!("0f", "fd"), ShortRead);
1203                 do_test!(concat!("0f", "fd26"), ShortRead);
1204                 do_test!(concat!("0f", "fd2602"), ShortRead);
1205                 do_test!(concat!("0f", "fd0001", "00"), InvalidValue);
1206                 do_test!(concat!("0f", "fd0201", "000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"), ShortRead);
1207
1208                 do_test!(concat!("12", "00"), UnknownRequiredFeature);
1209                 do_test!(concat!("fd0102", "00"), UnknownRequiredFeature);
1210                 do_test!(concat!("fe01000002", "00"), UnknownRequiredFeature);
1211                 do_test!(concat!("ff0100000000000002", "00"), UnknownRequiredFeature);
1212         }
1213
1214         #[test]
1215         fn bolt_tlv_bogus_n1_stream() {
1216                 macro_rules! do_test {
1217                         ($stream: expr, $reason: ident) => {
1218                                 if let Err(DecodeError::$reason) = tlv_reader_n1(&::hex::decode($stream).unwrap()[..]) {
1219                                 } else { panic!(); }
1220                         }
1221                 }
1222
1223                 // TLVs from the BOLT test cases which should not decode as n1
1224                 do_test!(concat!("01", "09", "ffffffffffffffffff"), InvalidValue);
1225                 do_test!(concat!("01", "01", "00"), InvalidValue);
1226                 do_test!(concat!("01", "02", "0001"), InvalidValue);
1227                 do_test!(concat!("01", "03", "000100"), InvalidValue);
1228                 do_test!(concat!("01", "04", "00010000"), InvalidValue);
1229                 do_test!(concat!("01", "05", "0001000000"), InvalidValue);
1230                 do_test!(concat!("01", "06", "000100000000"), InvalidValue);
1231                 do_test!(concat!("01", "07", "00010000000000"), InvalidValue);
1232                 do_test!(concat!("01", "08", "0001000000000000"), InvalidValue);
1233                 do_test!(concat!("02", "07", "01010101010101"), ShortRead);
1234                 do_test!(concat!("02", "09", "010101010101010101"), InvalidValue);
1235                 do_test!(concat!("03", "21", "023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb"), ShortRead);
1236                 do_test!(concat!("03", "29", "023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb0000000000000001"), ShortRead);
1237                 do_test!(concat!("03", "30", "023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb000000000000000100000000000001"), ShortRead);
1238                 do_test!(concat!("03", "31", "043da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb00000000000000010000000000000002"), InvalidValue);
1239                 do_test!(concat!("03", "32", "023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb0000000000000001000000000000000001"), InvalidValue);
1240                 do_test!(concat!("fd00fe", "00"), ShortRead);
1241                 do_test!(concat!("fd00fe", "01", "01"), ShortRead);
1242                 do_test!(concat!("fd00fe", "03", "010101"), InvalidValue);
1243                 do_test!(concat!("00", "00"), UnknownRequiredFeature);
1244
1245                 do_test!(concat!("02", "08", "0000000000000226", "01", "01", "2a"), InvalidValue);
1246                 do_test!(concat!("02", "08", "0000000000000231", "02", "08", "0000000000000451"), InvalidValue);
1247                 do_test!(concat!("1f", "00", "0f", "01", "2a"), InvalidValue);
1248                 do_test!(concat!("1f", "00", "1f", "01", "2a"), InvalidValue);
1249
1250                 // The last BOLT test modified to not require creating a new decoder for one trivial test.
1251                 do_test!(concat!("ffffffffffffffffff", "00", "01", "00"), InvalidValue);
1252         }
1253
1254         #[test]
1255         fn bolt_tlv_valid_n1_stream() {
1256                 macro_rules! do_test {
1257                         ($stream: expr, $tlv1: expr, $tlv2: expr, $tlv3: expr, $tlv4: expr) => {
1258                                 if let Ok((tlv1, tlv2, tlv3, tlv4)) = tlv_reader_n1(&::hex::decode($stream).unwrap()[..]) {
1259                                         assert_eq!(tlv1.map(|v| v.0), $tlv1);
1260                                         assert_eq!(tlv2, $tlv2);
1261                                         assert_eq!(tlv3, $tlv3);
1262                                         assert_eq!(tlv4, $tlv4);
1263                                 } else { panic!(); }
1264                         }
1265                 }
1266
1267                 do_test!(concat!(""), None, None, None, None);
1268                 do_test!(concat!("21", "00"), None, None, None, None);
1269                 do_test!(concat!("fd0201", "00"), None, None, None, None);
1270                 do_test!(concat!("fd00fd", "00"), None, None, None, None);
1271                 do_test!(concat!("fd00ff", "00"), None, None, None, None);
1272                 do_test!(concat!("fe02000001", "00"), None, None, None, None);
1273                 do_test!(concat!("ff0200000000000001", "00"), None, None, None, None);
1274
1275                 do_test!(concat!("01", "00"), Some(0), None, None, None);
1276                 do_test!(concat!("01", "01", "01"), Some(1), None, None, None);
1277                 do_test!(concat!("01", "02", "0100"), Some(256), None, None, None);
1278                 do_test!(concat!("01", "03", "010000"), Some(65536), None, None, None);
1279                 do_test!(concat!("01", "04", "01000000"), Some(16777216), None, None, None);
1280                 do_test!(concat!("01", "05", "0100000000"), Some(4294967296), None, None, None);
1281                 do_test!(concat!("01", "06", "010000000000"), Some(1099511627776), None, None, None);
1282                 do_test!(concat!("01", "07", "01000000000000"), Some(281474976710656), None, None, None);
1283                 do_test!(concat!("01", "08", "0100000000000000"), Some(72057594037927936), None, None, None);
1284                 do_test!(concat!("02", "08", "0000000000000226"), None, Some((0 << 30) | (0 << 5) | (550 << 0)), None, None);
1285                 do_test!(concat!("03", "31", "023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb00000000000000010000000000000002"),
1286                         None, None, Some((
1287                                 PublicKey::from_slice(&::hex::decode("023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb").unwrap()[..]).unwrap(), 1, 2)),
1288                         None);
1289                 do_test!(concat!("fd00fe", "02", "0226"), None, None, None, Some(550));
1290         }
1291
1292         fn do_simple_test_tlv_write() -> Result<(), io::Error> {
1293                 let mut stream = VecWriter(Vec::new());
1294
1295                 stream.0.clear();
1296                 _encode_varint_length_prefixed_tlv!(&mut stream, {(1, 1u8, required), (42, None::<u64>, option)});
1297                 assert_eq!(stream.0, ::hex::decode("03010101").unwrap());
1298
1299                 stream.0.clear();
1300                 _encode_varint_length_prefixed_tlv!(&mut stream, {(1, Some(1u8), option)});
1301                 assert_eq!(stream.0, ::hex::decode("03010101").unwrap());
1302
1303                 stream.0.clear();
1304                 _encode_varint_length_prefixed_tlv!(&mut stream, {(4, 0xabcdu16, required), (42, None::<u64>, option)});
1305                 assert_eq!(stream.0, ::hex::decode("040402abcd").unwrap());
1306
1307                 stream.0.clear();
1308                 _encode_varint_length_prefixed_tlv!(&mut stream, {(42, None::<u64>, option), (0xff, 0xabcdu16, required)});
1309                 assert_eq!(stream.0, ::hex::decode("06fd00ff02abcd").unwrap());
1310
1311                 stream.0.clear();
1312                 _encode_varint_length_prefixed_tlv!(&mut stream, {(0, 1u64, required), (42, None::<u64>, option), (0xff, HighZeroBytesDroppedBigSize(0u64), required)});
1313                 assert_eq!(stream.0, ::hex::decode("0e00080000000000000001fd00ff00").unwrap());
1314
1315                 stream.0.clear();
1316                 _encode_varint_length_prefixed_tlv!(&mut stream, {(0, Some(1u64), option), (0xff, HighZeroBytesDroppedBigSize(0u64), required)});
1317                 assert_eq!(stream.0, ::hex::decode("0e00080000000000000001fd00ff00").unwrap());
1318
1319                 Ok(())
1320         }
1321
1322         #[test]
1323         fn simple_test_tlv_write() {
1324                 do_simple_test_tlv_write().unwrap();
1325         }
1326 }