_ 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 macro_rules! encode_tlv {
  11         ($stream: expr, $type: expr, $field: expr, (default_value, $default: expr)) => {
  12                 encode_tlv!($stream, $type, $field, required)
  13         };
  14         ($stream: expr, $type: expr, $field: expr, required) => {
  15                 BigSize($type).write($stream)?;
  16                 BigSize($field.serialized_length() as u64).write($stream)?;
  17                 $field.write($stream)?;
  18         };
  19         ($stream: expr, $type: expr, $field: expr, vec_type) => {
  20                 encode_tlv!($stream, $type, ::util::ser::VecWriteWrapper(&$field), required);
  21         };
  22         ($stream: expr, $optional_type: expr, $optional_field: expr, option) => {
  23                 if let Some(ref field) = $optional_field {
  24                         BigSize($optional_type).write($stream)?;
  25                         BigSize(field.serialized_length() as u64).write($stream)?;
  26                         field.write($stream)?;
  27                 }
  28         };
  29 }
  30
  31 macro_rules! encode_tlv_stream {
  32         ($stream: expr, {$(($type: expr, $field: expr, $fieldty: tt)),* $(,)*}) => { {
  33                 #[allow(unused_imports)]
  34                 use {
  35                         ln::msgs::DecodeError,
  36                         util::ser,
  37                         util::ser::BigSize,
  38                 };
  39
  40                 $(
  41                         encode_tlv!($stream, $type, $field, $fieldty);
  42                 )*
  43
  44                 #[allow(unused_mut, unused_variables, unused_assignments)]
  45                 #[cfg(debug_assertions)]
  46                 {
  47                         let mut last_seen: Option<u64> = None;
  48                         $(
  49                                 if let Some(t) = last_seen {
  50                                         debug_assert!(t <= $type);
  51                                 }
  52                                 last_seen = Some($type);
  53                         )*
  54                 }
  55         } }
  56 }
  57
  58 macro_rules! get_varint_length_prefixed_tlv_length {
  59         ($len: expr, $type: expr, $field: expr, (default_value, $default: expr)) => {
  60                 get_varint_length_prefixed_tlv_length!($len, $type, $field, required)
  61         };
  62         ($len: expr, $type: expr, $field: expr, required) => {
  63                 BigSize($type).write(&mut $len).expect("No in-memory data may fail to serialize");
  64                 let field_len = $field.serialized_length();
  65                 BigSize(field_len as u64).write(&mut $len).expect("No in-memory data may fail to serialize");
  66                 $len.0 += field_len;
  67         };
  68         ($len: expr, $type: expr, $field: expr, vec_type) => {
  69                 get_varint_length_prefixed_tlv_length!($len, $type, ::util::ser::VecWriteWrapper(&$field), required);
  70         };
  71         ($len: expr, $optional_type: expr, $optional_field: expr, option) => {
  72                 if let Some(ref field) = $optional_field {
  73                         BigSize($optional_type).write(&mut $len).expect("No in-memory data may fail to serialize");
  74                         let field_len = field.serialized_length();
  75                         BigSize(field_len as u64).write(&mut $len).expect("No in-memory data may fail to serialize");
  76                         $len.0 += field_len;
  77                 }
  78         };
  79 }
  80
  81 macro_rules! encode_varint_length_prefixed_tlv {
  82         ($stream: expr, {$(($type: expr, $field: expr, $fieldty: tt)),*}) => { {
  83                 use util::ser::BigSize;
  84                 let len = {
  85                         #[allow(unused_mut)]
  86                         let mut len = ::util::ser::LengthCalculatingWriter(0);
  87                         $(
  88                                 get_varint_length_prefixed_tlv_length!(len, $type, $field, $fieldty);
  89                         )*
  90                         len.0
  91                 };
  92                 BigSize(len as u64).write($stream)?;
  93                 encode_tlv_stream!($stream, { $(($type, $field, $fieldty)),* });
  94         } }
  95 }
  96
  97 macro_rules! check_tlv_order {
  98         ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, (default_value, $default: expr)) => {{
  99                 #[allow(unused_comparisons)] // Note that $type may be 0 making the second comparison always true
 100                 let invalid_order = ($last_seen_type.is_none() || $last_seen_type.unwrap() < $type) && $typ.0 > $type;
 101                 if invalid_order {
 102                         $field = $default.into();
 103                 }
 104         }};
 105         ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, required) => {{
 106                 #[allow(unused_comparisons)] // Note that $type may be 0 making the second comparison always true
 107                 let invalid_order = ($last_seen_type.is_none() || $last_seen_type.unwrap() < $type) && $typ.0 > $type;
 108                 if invalid_order {
 109                         return Err(DecodeError::InvalidValue);
 110                 }
 111         }};
 112         ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, option) => {{
 113                 // no-op
 114         }};
 115         ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, vec_type) => {{
 116                 // no-op
 117         }};
 118         ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, ignorable) => {{
 119                 // no-op
 120         }};
 121         ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, (option: $trait: ident $(, $read_arg: expr)?)) => {{
 122                 // no-op
 123         }};
 124 }
 125
 126 macro_rules! check_missing_tlv {
 127         ($last_seen_type: expr, $type: expr, $field: ident, (default_value, $default: expr)) => {{
 128                 #[allow(unused_comparisons)] // Note that $type may be 0 making the second comparison always true
 129                 let missing_req_type = $last_seen_type.is_none() || $last_seen_type.unwrap() < $type;
 130                 if missing_req_type {
 131                         $field = $default.into();
 132                 }
 133         }};
 134         ($last_seen_type: expr, $type: expr, $field: ident, required) => {{
 135                 #[allow(unused_comparisons)] // Note that $type may be 0 making the second comparison always true
 136                 let missing_req_type = $last_seen_type.is_none() || $last_seen_type.unwrap() < $type;
 137                 if missing_req_type {
 138                         return Err(DecodeError::InvalidValue);
 139                 }
 140         }};
 141         ($last_seen_type: expr, $type: expr, $field: ident, vec_type) => {{
 142                 // no-op
 143         }};
 144         ($last_seen_type: expr, $type: expr, $field: ident, option) => {{
 145                 // no-op
 146         }};
 147         ($last_seen_type: expr, $type: expr, $field: ident, ignorable) => {{
 148                 // no-op
 149         }};
 150         ($last_seen_type: expr, $type: expr, $field: ident, (option: $trait: ident $(, $read_arg: expr)?)) => {{
 151                 // no-op
 152         }};
 153 }
 154
 155 macro_rules! decode_tlv {
 156         ($reader: expr, $field: ident, (default_value, $default: expr)) => {{
 157                 decode_tlv!($reader, $field, required)
 158         }};
 159         ($reader: expr, $field: ident, required) => {{
 160                 $field = ::util::ser::Readable::read(&mut $reader)?;
 161         }};
 162         ($reader: expr, $field: ident, vec_type) => {{
 163                 let f: ::util::ser::VecReadWrapper<_> = ::util::ser::Readable::read(&mut $reader)?;
 164                 $field = Some(f.0);
 165         }};
 166         ($reader: expr, $field: ident, option) => {{
 167                 $field = Some(::util::ser::Readable::read(&mut $reader)?);
 168         }};
 169         ($reader: expr, $field: ident, ignorable) => {{
 170                 $field = ::util::ser::MaybeReadable::read(&mut $reader)?;
 171         }};
 172         ($reader: expr, $field: ident, (option: $trait: ident $(, $read_arg: expr)?)) => {{
 173                 $field = Some($trait::read(&mut $reader $(, $read_arg)*)?);
 174         }};
 175 }
 176
 177 // `$decode_custom_tlv` is a closure that may be optionally provided to handle custom message types.
 178 // If it is provided, it will be called with the custom type and the `FixedLengthReader` containing
 179 // the message contents. It should return `Ok(true)` if the custom message is successfully parsed,
 180 // `Ok(false)` if the message type is unknown, and `Err(DecodeError)` if parsing fails.
 181 macro_rules! decode_tlv_stream {
 182         ($stream: expr, {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}
 183          $(, $decode_custom_tlv: expr)?) => { {
 184                 use ln::msgs::DecodeError;
 185                 let mut last_seen_type: Option<u64> = None;
 186                 let mut stream_ref = $stream;
 187                 'tlv_read: loop {
 188                         use util::ser;
 189
 190                         // First decode the type of this TLV:
 191                         let typ: ser::BigSize = {
 192                                 // We track whether any bytes were read during the consensus_decode call to
 193                                 // determine whether we should break or return ShortRead if we get an
 194                                 // UnexpectedEof. This should in every case be largely cosmetic, but its nice to
 195                                 // pass the TLV test vectors exactly, which requre this distinction.
 196                                 let mut tracking_reader = ser::ReadTrackingReader::new(&mut stream_ref);
 197                                 match ser::Readable::read(&mut tracking_reader) {
 198                                         Err(DecodeError::ShortRead) => {
 199                                                 if !tracking_reader.have_read {
 200                                                         break 'tlv_read;
 201                                                 } else {
 202                                                         return Err(DecodeError::ShortRead);
 203                                                 }
 204                                         },
 205                                         Err(e) => return Err(e),
 206                                         Ok(t) => t,
 207                                 }
 208                         };
 209
 210                         // Types must be unique and monotonically increasing:
 211                         match last_seen_type {
 212                                 Some(t) if typ.0 <= t => {
 213                                         return Err(DecodeError::InvalidValue);
 214                                 },
 215                                 _ => {},
 216                         }
 217                         // As we read types, make sure we hit every required type:
 218                         $({
 219                                 check_tlv_order!(last_seen_type, typ, $type, $field, $fieldty);
 220                         })*
 221                         last_seen_type = Some(typ.0);
 222
 223                         // Finally, read the length and value itself:
 224                         let length: ser::BigSize = ser::Readable::read(&mut stream_ref)?;
 225                         let mut s = ser::FixedLengthReader::new(&mut stream_ref, length.0);
 226                         match typ.0 {
 227                                 $($type => {
 228                                         decode_tlv!(s, $field, $fieldty);
 229                                         if s.bytes_remain() {
 230                                                 s.eat_remaining()?; // Return ShortRead if there's actually not enough bytes
 231                                                 return Err(DecodeError::InvalidValue);
 232                                         }
 233                                 },)*
 234                                 t => {
 235                                         $(
 236                                                 if $decode_custom_tlv(t, &mut s)? {
 237                                                         // If a custom TLV was successfully read (i.e. decode_custom_tlv returns true),
 238                                                         // continue to the next TLV read.
 239                                                         s.eat_remaining()?;
 240                                                         continue 'tlv_read;
 241                                                 }
 242                                         )?
 243                                         if t % 2 == 0 {
 244                                                 return Err(DecodeError::UnknownRequiredFeature);
 245                                         }
 246                                 }
 247                         }
 248                         s.eat_remaining()?;
 249                 }
 250                 // Make sure we got to each required type after we've read every TLV:
 251                 $({
 252                         check_missing_tlv!(last_seen_type, $type, $field, $fieldty);
 253                 })*
 254         } }
 255 }
 256
 257 macro_rules! impl_writeable_msg {
 258         ($st:ident, {$($field:ident),* $(,)*}, {$(($type: expr, $tlvfield: ident, $fieldty: tt)),* $(,)*}) => {
 259                 impl ::util::ser::Writeable for $st {
 260                         fn write<W: ::util::ser::Writer>(&self, w: &mut W) -> Result<(), $crate::io::Error> {
 261                                 $( self.$field.write(w)?; )*
 262                                 encode_tlv_stream!(w, {$(($type, self.$tlvfield, $fieldty)),*});
 263                                 Ok(())
 264                         }
 265                 }
 266                 impl ::util::ser::Readable for $st {
 267                         fn read<R: $crate::io::Read>(r: &mut R) -> Result<Self, ::ln::msgs::DecodeError> {
 268                                 $(let $field = ::util::ser::Readable::read(r)?;)*
 269                                 $(init_tlv_field_var!($tlvfield, $fieldty);)*
 270                                 decode_tlv_stream!(r, {$(($type, $tlvfield, $fieldty)),*});
 271                                 Ok(Self {
 272                                         $($field),*,
 273                                         $($tlvfield),*
 274                                 })
 275                         }
 276                 }
 277         }
 278 }
 279
 280 macro_rules! impl_writeable {
 281         ($st:ident, {$($field:ident),*}) => {
 282                 impl ::util::ser::Writeable for $st {
 283                         fn write<W: ::util::ser::Writer>(&self, w: &mut W) -> Result<(), $crate::io::Error> {
 284                                 $( self.$field.write(w)?; )*
 285                                 Ok(())
 286                         }
 287
 288                         #[inline]
 289                         fn serialized_length(&self) -> usize {
 290                                 let mut len_calc = 0;
 291                                 $( len_calc += self.$field.serialized_length(); )*
 292                                 return len_calc;
 293                         }
 294                 }
 295
 296                 impl ::util::ser::Readable for $st {
 297                         fn read<R: $crate::io::Read>(r: &mut R) -> Result<Self, ::ln::msgs::DecodeError> {
 298                                 Ok(Self {
 299                                         $($field: ::util::ser::Readable::read(r)?),*
 300                                 })
 301                         }
 302                 }
 303         }
 304 }
 305
 306 /// Write out two bytes to indicate the version of an object.
 307 /// $this_version represents a unique version of a type. Incremented whenever the type's
 308 ///               serialization format has changed or has a new interpretation. Used by a type's
 309 ///               reader to determine how to interpret fields or if it can understand a serialized
 310 ///               object.
 311 /// $min_version_that_can_read_this is the minimum reader version which can understand this
 312 ///                                 serialized object. Previous versions will simply err with a
 313 ///                                 DecodeError::UnknownVersion.
 314 ///
 315 /// Updates to either $this_version or $min_version_that_can_read_this should be included in
 316 /// release notes.
 317 ///
 318 /// Both version fields can be specific to this type of object.
 319 macro_rules! write_ver_prefix {
 320         ($stream: expr, $this_version: expr, $min_version_that_can_read_this: expr) => {
 321                 $stream.write_all(&[$this_version; 1])?;
 322                 $stream.write_all(&[$min_version_that_can_read_this; 1])?;
 323         }
 324 }
 325
 326 /// Writes out a suffix to an object which contains potentially backwards-compatible, optional
 327 /// fields which old nodes can happily ignore.
 328 ///
 329 /// It is written out in TLV format and, as with all TLV fields, unknown even fields cause a
 330 /// DecodeError::UnknownRequiredFeature error, with unknown odd fields ignored.
 331 ///
 332 /// This is the preferred method of adding new fields that old nodes can ignore and still function
 333 /// correctly.
 334 macro_rules! write_tlv_fields {
 335         ($stream: expr, {$(($type: expr, $field: expr, $fieldty: tt)),* $(,)*}) => {
 336                 encode_varint_length_prefixed_tlv!($stream, {$(($type, $field, $fieldty)),*})
 337         }
 338 }
 339
 340 /// Reads a prefix added by write_ver_prefix!(), above. Takes the current version of the
 341 /// serialization logic for this object. This is compared against the
 342 /// $min_version_that_can_read_this added by write_ver_prefix!().
 343 macro_rules! read_ver_prefix {
 344         ($stream: expr, $this_version: expr) => { {
 345                 let ver: u8 = Readable::read($stream)?;
 346                 let min_ver: u8 = Readable::read($stream)?;
 347                 if min_ver > $this_version {
 348                         return Err(DecodeError::UnknownVersion);
 349                 }
 350                 ver
 351         } }
 352 }
 353
 354 /// Reads a suffix added by write_tlv_fields.
 355 macro_rules! read_tlv_fields {
 356         ($stream: expr, {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}) => { {
 357                 let tlv_len: ::util::ser::BigSize = ::util::ser::Readable::read($stream)?;
 358                 let mut rd = ::util::ser::FixedLengthReader::new($stream, tlv_len.0);
 359                 decode_tlv_stream!(&mut rd, {$(($type, $field, $fieldty)),*});
 360                 rd.eat_remaining().map_err(|_| ::ln::msgs::DecodeError::ShortRead)?;
 361         } }
 362 }
 363
 364 macro_rules! init_tlv_based_struct_field {
 365         ($field: ident, (default_value, $default: expr)) => {
 366                 $field.0.unwrap()
 367         };
 368         ($field: ident, option) => {
 369                 $field
 370         };
 371         ($field: ident, required) => {
 372                 $field.0.unwrap()
 373         };
 374         ($field: ident, vec_type) => {
 375                 $field.unwrap()
 376         };
 377 }
 378
 379 macro_rules! init_tlv_field_var {
 380         ($field: ident, (default_value, $default: expr)) => {
 381                 let mut $field = ::util::ser::OptionDeserWrapper(None);
 382         };
 383         ($field: ident, required) => {
 384                 let mut $field = ::util::ser::OptionDeserWrapper(None);
 385         };
 386         ($field: ident, vec_type) => {
 387                 let mut $field = Some(Vec::new());
 388         };
 389         ($field: ident, option) => {
 390                 let mut $field = None;
 391         };
 392 }
 393
 394 /// Implements Readable/Writeable for a struct storing it as a set of TLVs
 395 /// If $fieldty is `required`, then $field is a required field that is not an Option nor a Vec.
 396 /// If $fieldty is `option`, then $field is optional field.
 397 /// if $fieldty is `vec_type`, then $field is a Vec, which needs to have its individual elements
 398 /// serialized.
 399 macro_rules! impl_writeable_tlv_based {
 400         ($st: ident, {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}) => {
 401                 impl ::util::ser::Writeable for $st {
 402                         fn write<W: ::util::ser::Writer>(&self, writer: &mut W) -> Result<(), $crate::io::Error> {
 403                                 write_tlv_fields!(writer, {
 404                                         $(($type, self.$field, $fieldty)),*
 405                                 });
 406                                 Ok(())
 407                         }
 408
 409                         #[inline]
 410                         fn serialized_length(&self) -> usize {
 411                                 use util::ser::BigSize;
 412                                 let len = {
 413                                         #[allow(unused_mut)]
 414                                         let mut len = ::util::ser::LengthCalculatingWriter(0);
 415                                         $(
 416                                                 get_varint_length_prefixed_tlv_length!(len, $type, self.$field, $fieldty);
 417                                         )*
 418                                         len.0
 419                                 };
 420                                 let mut len_calc = ::util::ser::LengthCalculatingWriter(0);
 421                                 BigSize(len as u64).write(&mut len_calc).expect("No in-memory data may fail to serialize");
 422                                 len + len_calc.0
 423                         }
 424                 }
 425
 426                 impl ::util::ser::Readable for $st {
 427                         fn read<R: $crate::io::Read>(reader: &mut R) -> Result<Self, ::ln::msgs::DecodeError> {
 428                                 $(
 429                                         init_tlv_field_var!($field, $fieldty);
 430                                 )*
 431                                 read_tlv_fields!(reader, {
 432                                         $(($type, $field, $fieldty)),*
 433                                 });
 434                                 Ok(Self {
 435                                         $(
 436                                                 $field: init_tlv_based_struct_field!($field, $fieldty)
 437                                         ),*
 438                                 })
 439                         }
 440                 }
 441         }
 442 }
 443
 444 macro_rules! _impl_writeable_tlv_based_enum_common {
 445         ($st: ident, $(($variant_id: expr, $variant_name: ident) =>
 446                 {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}
 447         ),* $(,)*;
 448         $(($tuple_variant_id: expr, $tuple_variant_name: ident)),*  $(,)*) => {
 449                 impl ::util::ser::Writeable for $st {
 450                         fn write<W: ::util::ser::Writer>(&self, writer: &mut W) -> Result<(), $crate::io::Error> {
 451                                 match self {
 452                                         $($st::$variant_name { $(ref $field),* } => {
 453                                                 let id: u8 = $variant_id;
 454                                                 id.write(writer)?;
 455                                                 write_tlv_fields!(writer, {
 456                                                         $(($type, $field, $fieldty)),*
 457                                                 });
 458                                         }),*
 459                                         $($st::$tuple_variant_name (ref field) => {
 460                                                 let id: u8 = $tuple_variant_id;
 461                                                 id.write(writer)?;
 462                                                 field.write(writer)?;
 463                                         }),*
 464                                 }
 465                                 Ok(())
 466                         }
 467                 }
 468         }
 469 }
 470
 471 /// Implement MaybeReadable and Writeable for an enum, with struct variants stored as TLVs and
 472 /// tuple variants stored directly.
 473 ///
 474 /// This is largely identical to `impl_writeable_tlv_based_enum`, except that odd variants will
 475 /// return `Ok(None)` instead of `Err(UnknownRequiredFeature)`. It should generally be preferred
 476 /// when `MaybeReadable` is practical instead of just `Readable` as it provides an upgrade path for
 477 /// new variants to be added which are simply ignored by existing clients.
 478 macro_rules! impl_writeable_tlv_based_enum_upgradable {
 479         ($st: ident, $(($variant_id: expr, $variant_name: ident) =>
 480                 {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}
 481         ),* $(,)*
 482         $(;
 483         $(($tuple_variant_id: expr, $tuple_variant_name: ident)),*  $(,)*)*) => {
 484                 _impl_writeable_tlv_based_enum_common!($st,
 485                         $(($variant_id, $variant_name) => {$(($type, $field, $fieldty)),*}),*;
 486                         $($(($tuple_variant_id, $tuple_variant_name)),*)*);
 487
 488                 impl ::util::ser::MaybeReadable for $st {
 489                         fn read<R: $crate::io::Read>(reader: &mut R) -> Result<Option<Self>, ::ln::msgs::DecodeError> {
 490                                 let id: u8 = ::util::ser::Readable::read(reader)?;
 491                                 match id {
 492                                         $($variant_id => {
 493                                                 // Because read_tlv_fields creates a labeled loop, we cannot call it twice
 494                                                 // in the same function body. Instead, we define a closure and call it.
 495                                                 let f = || {
 496                                                         $(
 497                                                                 init_tlv_field_var!($field, $fieldty);
 498                                                         )*
 499                                                         read_tlv_fields!(reader, {
 500                                                                 $(($type, $field, $fieldty)),*
 501                                                         });
 502                                                         Ok(Some($st::$variant_name {
 503                                                                 $(
 504                                                                         $field: init_tlv_based_struct_field!($field, $fieldty)
 505                                                                 ),*
 506                                                         }))
 507                                                 };
 508                                                 f()
 509                                         }),*
 510                                         $($($tuple_variant_id => {
 511                                                 Ok(Some($st::$tuple_variant_name(Readable::read(reader)?)))
 512                                         }),*)*
 513                                         _ if id % 2 == 1 => Ok(None),
 514                                         _ => Err(DecodeError::UnknownRequiredFeature),
 515                                 }
 516                         }
 517                 }
 518
 519         }
 520 }
 521
 522 /// Implement Readable and Writeable for an enum, with struct variants stored as TLVs and tuple
 523 /// variants stored directly.
 524 /// The format is, for example
 525 /// impl_writeable_tlv_based_enum!(EnumName,
 526 ///   (0, StructVariantA) => {(0, required_variant_field, required), (1, optional_variant_field, option)},
 527 ///   (1, StructVariantB) => {(0, variant_field_a, required), (1, variant_field_b, required), (2, variant_vec_field, vec_type)};
 528 ///   (2, TupleVariantA), (3, TupleVariantB),
 529 /// );
 530 /// The type is written as a single byte, followed by any variant data.
 531 /// Attempts to read an unknown type byte result in DecodeError::UnknownRequiredFeature.
 532 macro_rules! impl_writeable_tlv_based_enum {
 533         ($st: ident, $(($variant_id: expr, $variant_name: ident) =>
 534                 {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}
 535         ),* $(,)*;
 536         $(($tuple_variant_id: expr, $tuple_variant_name: ident)),*  $(,)*) => {
 537                 _impl_writeable_tlv_based_enum_common!($st,
 538                         $(($variant_id, $variant_name) => {$(($type, $field, $fieldty)),*}),*;
 539                         $(($tuple_variant_id, $tuple_variant_name)),*);
 540
 541                 impl ::util::ser::Readable for $st {
 542                         fn read<R: $crate::io::Read>(reader: &mut R) -> Result<Self, ::ln::msgs::DecodeError> {
 543                                 let id: u8 = ::util::ser::Readable::read(reader)?;
 544                                 match id {
 545                                         $($variant_id => {
 546                                                 // Because read_tlv_fields creates a labeled loop, we cannot call it twice
 547                                                 // in the same function body. Instead, we define a closure and call it.
 548                                                 let f = || {
 549                                                         $(
 550                                                                 init_tlv_field_var!($field, $fieldty);
 551                                                         )*
 552                                                         read_tlv_fields!(reader, {
 553                                                                 $(($type, $field, $fieldty)),*
 554                                                         });
 555                                                         Ok($st::$variant_name {
 556                                                                 $(
 557                                                                         $field: init_tlv_based_struct_field!($field, $fieldty)
 558                                                                 ),*
 559                                                         })
 560                                                 };
 561                                                 f()
 562                                         }),*
 563                                         $($tuple_variant_id => {
 564                                                 Ok($st::$tuple_variant_name(Readable::read(reader)?))
 565                                         }),*
 566                                         _ => {
 567                                                 Err(DecodeError::UnknownRequiredFeature)
 568                                         },
 569                                 }
 570                         }
 571                 }
 572         }
 573 }
 574
 575 #[cfg(test)]
 576 mod tests {
 577         use io::{self, Cursor};
 578         use prelude::*;
 579         use ln::msgs::DecodeError;
 580         use util::ser::{Writeable, HighZeroBytesDroppedBigSize, VecWriter};
 581         use bitcoin::secp256k1::PublicKey;
 582
 583         // The BOLT TLV test cases don't include any tests which use our "required-value" logic since
 584         // the encoding layer in the BOLTs has no such concept, though it makes our macros easier to
 585         // work with so they're baked into the decoder. Thus, we have a few additional tests below
 586         fn tlv_reader(s: &[u8]) -> Result<(u64, u32, Option<u32>), DecodeError> {
 587                 let mut s = Cursor::new(s);
 588                 let mut a: u64 = 0;
 589                 let mut b: u32 = 0;
 590                 let mut c: Option<u32> = None;
 591                 decode_tlv_stream!(&mut s, {(2, a, required), (3, b, required), (4, c, option)});
 592                 Ok((a, b, c))
 593         }
 594
 595         #[test]
 596         fn tlv_v_short_read() {
 597                 // We only expect a u32 for type 3 (which we are given), but the L says its 8 bytes.
 598                 if let Err(DecodeError::ShortRead) = tlv_reader(&::hex::decode(
 599                                 concat!("0100", "0208deadbeef1badbeef", "0308deadbeef")
 600                                 ).unwrap()[..]) {
 601                 } else { panic!(); }
 602         }
 603
 604         #[test]
 605         fn tlv_types_out_of_order() {
 606                 if let Err(DecodeError::InvalidValue) = tlv_reader(&::hex::decode(
 607                                 concat!("0100", "0304deadbeef", "0208deadbeef1badbeef")
 608                                 ).unwrap()[..]) {
 609                 } else { panic!(); }
 610                 // ...even if its some field we don't understand
 611                 if let Err(DecodeError::InvalidValue) = tlv_reader(&::hex::decode(
 612                                 concat!("0208deadbeef1badbeef", "0100", "0304deadbeef")
 613                                 ).unwrap()[..]) {
 614                 } else { panic!(); }
 615         }
 616
 617         #[test]
 618         fn tlv_req_type_missing_or_extra() {
 619                 // It's also bad if they included even fields we don't understand
 620                 if let Err(DecodeError::UnknownRequiredFeature) = tlv_reader(&::hex::decode(
 621                                 concat!("0100", "0208deadbeef1badbeef", "0304deadbeef", "0600")
 622                                 ).unwrap()[..]) {
 623                 } else { panic!(); }
 624                 // ... or if they're missing fields we need
 625                 if let Err(DecodeError::InvalidValue) = tlv_reader(&::hex::decode(
 626                                 concat!("0100", "0208deadbeef1badbeef")
 627                                 ).unwrap()[..]) {
 628                 } else { panic!(); }
 629                 // ... even if that field is even
 630                 if let Err(DecodeError::InvalidValue) = tlv_reader(&::hex::decode(
 631                                 concat!("0304deadbeef", "0500")
 632                                 ).unwrap()[..]) {
 633                 } else { panic!(); }
 634         }
 635
 636         #[test]
 637         fn tlv_simple_good_cases() {
 638                 assert_eq!(tlv_reader(&::hex::decode(
 639                                 concat!("0208deadbeef1badbeef", "03041bad1dea")
 640                                 ).unwrap()[..]).unwrap(),
 641                         (0xdeadbeef1badbeef, 0x1bad1dea, None));
 642                 assert_eq!(tlv_reader(&::hex::decode(
 643                                 concat!("0208deadbeef1badbeef", "03041bad1dea", "040401020304")
 644                                 ).unwrap()[..]).unwrap(),
 645                         (0xdeadbeef1badbeef, 0x1bad1dea, Some(0x01020304)));
 646         }
 647
 648         // BOLT TLV test cases
 649         fn tlv_reader_n1(s: &[u8]) -> Result<(Option<HighZeroBytesDroppedBigSize<u64>>, Option<u64>, Option<(PublicKey, u64, u64)>, Option<u16>), DecodeError> {
 650                 let mut s = Cursor::new(s);
 651                 let mut tlv1: Option<HighZeroBytesDroppedBigSize<u64>> = None;
 652                 let mut tlv2: Option<u64> = None;
 653                 let mut tlv3: Option<(PublicKey, u64, u64)> = None;
 654                 let mut tlv4: Option<u16> = None;
 655                 decode_tlv_stream!(&mut s, {(1, tlv1, option), (2, tlv2, option), (3, tlv3, option), (254, tlv4, option)});
 656                 Ok((tlv1, tlv2, tlv3, tlv4))
 657         }
 658
 659         #[test]
 660         fn bolt_tlv_bogus_stream() {
 661                 macro_rules! do_test {
 662                         ($stream: expr, $reason: ident) => {
 663                                 if let Err(DecodeError::$reason) = tlv_reader_n1(&::hex::decode($stream).unwrap()[..]) {
 664                                 } else { panic!(); }
 665                         }
 666                 }
 667
 668                 // TLVs from the BOLT test cases which should not decode as either n1 or n2
 669                 do_test!(concat!("fd01"), ShortRead);
 670                 do_test!(concat!("fd0001", "00"), InvalidValue);
 671                 do_test!(concat!("fd0101"), ShortRead);
 672                 do_test!(concat!("0f", "fd"), ShortRead);
 673                 do_test!(concat!("0f", "fd26"), ShortRead);
 674                 do_test!(concat!("0f", "fd2602"), ShortRead);
 675                 do_test!(concat!("0f", "fd0001", "00"), InvalidValue);
 676                 do_test!(concat!("0f", "fd0201", "000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"), ShortRead);
 677
 678                 do_test!(concat!("12", "00"), UnknownRequiredFeature);
 679                 do_test!(concat!("fd0102", "00"), UnknownRequiredFeature);
 680                 do_test!(concat!("fe01000002", "00"), UnknownRequiredFeature);
 681                 do_test!(concat!("ff0100000000000002", "00"), UnknownRequiredFeature);
 682         }
 683
 684         #[test]
 685         fn bolt_tlv_bogus_n1_stream() {
 686                 macro_rules! do_test {
 687                         ($stream: expr, $reason: ident) => {
 688                                 if let Err(DecodeError::$reason) = tlv_reader_n1(&::hex::decode($stream).unwrap()[..]) {
 689                                 } else { panic!(); }
 690                         }
 691                 }
 692
 693                 // TLVs from the BOLT test cases which should not decode as n1
 694                 do_test!(concat!("01", "09", "ffffffffffffffffff"), InvalidValue);
 695                 do_test!(concat!("01", "01", "00"), InvalidValue);
 696                 do_test!(concat!("01", "02", "0001"), InvalidValue);
 697                 do_test!(concat!("01", "03", "000100"), InvalidValue);
 698                 do_test!(concat!("01", "04", "00010000"), InvalidValue);
 699                 do_test!(concat!("01", "05", "0001000000"), InvalidValue);
 700                 do_test!(concat!("01", "06", "000100000000"), InvalidValue);
 701                 do_test!(concat!("01", "07", "00010000000000"), InvalidValue);
 702                 do_test!(concat!("01", "08", "0001000000000000"), InvalidValue);
 703                 do_test!(concat!("02", "07", "01010101010101"), ShortRead);
 704                 do_test!(concat!("02", "09", "010101010101010101"), InvalidValue);
 705                 do_test!(concat!("03", "21", "023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb"), ShortRead);
 706                 do_test!(concat!("03", "29", "023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb0000000000000001"), ShortRead);
 707                 do_test!(concat!("03", "30", "023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb000000000000000100000000000001"), ShortRead);
 708                 do_test!(concat!("03", "31", "043da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb00000000000000010000000000000002"), InvalidValue);
 709                 do_test!(concat!("03", "32", "023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb0000000000000001000000000000000001"), InvalidValue);
 710                 do_test!(concat!("fd00fe", "00"), ShortRead);
 711                 do_test!(concat!("fd00fe", "01", "01"), ShortRead);
 712                 do_test!(concat!("fd00fe", "03", "010101"), InvalidValue);
 713                 do_test!(concat!("00", "00"), UnknownRequiredFeature);
 714
 715                 do_test!(concat!("02", "08", "0000000000000226", "01", "01", "2a"), InvalidValue);
 716                 do_test!(concat!("02", "08", "0000000000000231", "02", "08", "0000000000000451"), InvalidValue);
 717                 do_test!(concat!("1f", "00", "0f", "01", "2a"), InvalidValue);
 718                 do_test!(concat!("1f", "00", "1f", "01", "2a"), InvalidValue);
 719
 720                 // The last BOLT test modified to not require creating a new decoder for one trivial test.
 721                 do_test!(concat!("ffffffffffffffffff", "00", "01", "00"), InvalidValue);
 722         }
 723
 724         #[test]
 725         fn bolt_tlv_valid_n1_stream() {
 726                 macro_rules! do_test {
 727                         ($stream: expr, $tlv1: expr, $tlv2: expr, $tlv3: expr, $tlv4: expr) => {
 728                                 if let Ok((tlv1, tlv2, tlv3, tlv4)) = tlv_reader_n1(&::hex::decode($stream).unwrap()[..]) {
 729                                         assert_eq!(tlv1.map(|v| v.0), $tlv1);
 730                                         assert_eq!(tlv2, $tlv2);
 731                                         assert_eq!(tlv3, $tlv3);
 732                                         assert_eq!(tlv4, $tlv4);
 733                                 } else { panic!(); }
 734                         }
 735                 }
 736
 737                 do_test!(concat!(""), None, None, None, None);
 738                 do_test!(concat!("21", "00"), None, None, None, None);
 739                 do_test!(concat!("fd0201", "00"), None, None, None, None);
 740                 do_test!(concat!("fd00fd", "00"), None, None, None, None);
 741                 do_test!(concat!("fd00ff", "00"), None, None, None, None);
 742                 do_test!(concat!("fe02000001", "00"), None, None, None, None);
 743                 do_test!(concat!("ff0200000000000001", "00"), None, None, None, None);
 744
 745                 do_test!(concat!("01", "00"), Some(0), None, None, None);
 746                 do_test!(concat!("01", "01", "01"), Some(1), None, None, None);
 747                 do_test!(concat!("01", "02", "0100"), Some(256), None, None, None);
 748                 do_test!(concat!("01", "03", "010000"), Some(65536), None, None, None);
 749                 do_test!(concat!("01", "04", "01000000"), Some(16777216), None, None, None);
 750                 do_test!(concat!("01", "05", "0100000000"), Some(4294967296), None, None, None);
 751                 do_test!(concat!("01", "06", "010000000000"), Some(1099511627776), None, None, None);
 752                 do_test!(concat!("01", "07", "01000000000000"), Some(281474976710656), None, None, None);
 753                 do_test!(concat!("01", "08", "0100000000000000"), Some(72057594037927936), None, None, None);
 754                 do_test!(concat!("02", "08", "0000000000000226"), None, Some((0 << 30) | (0 << 5) | (550 << 0)), None, None);
 755                 do_test!(concat!("03", "31", "023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb00000000000000010000000000000002"),
 756                         None, None, Some((
 757                                 PublicKey::from_slice(&::hex::decode("023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb").unwrap()[..]).unwrap(), 1, 2)),
 758                         None);
 759                 do_test!(concat!("fd00fe", "02", "0226"), None, None, None, Some(550));
 760         }
 761
 762         fn do_simple_test_tlv_write() -> Result<(), io::Error> {
 763                 let mut stream = VecWriter(Vec::new());
 764
 765                 stream.0.clear();
 766                 encode_varint_length_prefixed_tlv!(&mut stream, {(1, 1u8, required), (42, None::<u64>, option)});
 767                 assert_eq!(stream.0, ::hex::decode("03010101").unwrap());
 768
 769                 stream.0.clear();
 770                 encode_varint_length_prefixed_tlv!(&mut stream, {(1, Some(1u8), option)});
 771                 assert_eq!(stream.0, ::hex::decode("03010101").unwrap());
 772
 773                 stream.0.clear();
 774                 encode_varint_length_prefixed_tlv!(&mut stream, {(4, 0xabcdu16, required), (42, None::<u64>, option)});
 775                 assert_eq!(stream.0, ::hex::decode("040402abcd").unwrap());
 776
 777                 stream.0.clear();
 778                 encode_varint_length_prefixed_tlv!(&mut stream, {(42, None::<u64>, option), (0xff, 0xabcdu16, required)});
 779                 assert_eq!(stream.0, ::hex::decode("06fd00ff02abcd").unwrap());
 780
 781                 stream.0.clear();
 782                 encode_varint_length_prefixed_tlv!(&mut stream, {(0, 1u64, required), (42, None::<u64>, option), (0xff, HighZeroBytesDroppedBigSize(0u64), required)});
 783                 assert_eq!(stream.0, ::hex::decode("0e00080000000000000001fd00ff00").unwrap());
 784
 785                 stream.0.clear();
 786                 encode_varint_length_prefixed_tlv!(&mut stream, {(0, Some(1u64), option), (0xff, HighZeroBytesDroppedBigSize(0u64), required)});
 787                 assert_eq!(stream.0, ::hex::decode("0e00080000000000000001fd00ff00").unwrap());
 788
 789                 Ok(())
 790         }
 791
 792         #[test]
 793         fn simple_test_tlv_write() {
 794                 do_simple_test_tlv_write().unwrap();
 795         }
 796 }