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

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