_ 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($stream)?;
  27                 }
  28         };
  29         ($stream: expr, $type: expr, $field: expr, (tlv_record, $fieldty:tt)) => {
  30                 if let Some(field) = $field {
  31                         let field: encoded_tlv_record_ref_type!($fieldty) = From::from(field);
  32                         BigSize($type).write($stream)?;
  33                         BigSize(field.serialized_length() as u64).write($stream)?;
  34                         field.write($stream)?;
  35                 }
  36         };
  37 }
  38
  39 macro_rules! encode_tlv_stream {
  40         ($stream: expr, {$(($type: expr, $field: expr, $fieldty: tt)),* $(,)*}) => { {
  41                 #[allow(unused_imports)]
  42                 use {
  43                         ln::msgs::DecodeError,
  44                         util::ser,
  45                         util::ser::BigSize,
  46                 };
  47
  48                 $(
  49                         encode_tlv!($stream, $type, $field, $fieldty);
  50                 )*
  51
  52                 #[allow(unused_mut, unused_variables, unused_assignments)]
  53                 #[cfg(debug_assertions)]
  54                 {
  55                         let mut last_seen: Option<u64> = None;
  56                         $(
  57                                 if let Some(t) = last_seen {
  58                                         debug_assert!(t <= $type);
  59                                 }
  60                                 last_seen = Some($type);
  61                         )*
  62                 }
  63         } }
  64 }
  65
  66 macro_rules! get_varint_length_prefixed_tlv_length {
  67         ($len: expr, $type: expr, $field: expr, (default_value, $default: expr)) => {
  68                 get_varint_length_prefixed_tlv_length!($len, $type, $field, required)
  69         };
  70         ($len: expr, $type: expr, $field: expr, required) => {
  71                 BigSize($type).write(&mut $len).expect("No in-memory data may fail to serialize");
  72                 let field_len = $field.serialized_length();
  73                 BigSize(field_len as u64).write(&mut $len).expect("No in-memory data may fail to serialize");
  74                 $len.0 += field_len;
  75         };
  76         ($len: expr, $type: expr, $field: expr, vec_type) => {
  77                 get_varint_length_prefixed_tlv_length!($len, $type, ::util::ser::VecWriteWrapper(&$field), required);
  78         };
  79         ($len: expr, $optional_type: expr, $optional_field: expr, option) => {
  80                 if let Some(ref field) = $optional_field {
  81                         BigSize($optional_type).write(&mut $len).expect("No in-memory data may fail to serialize");
  82                         let field_len = field.serialized_length();
  83                         BigSize(field_len as u64).write(&mut $len).expect("No in-memory data may fail to serialize");
  84                         $len.0 += field_len;
  85                 }
  86         };
  87 }
  88
  89 macro_rules! encode_varint_length_prefixed_tlv {
  90         ($stream: expr, {$(($type: expr, $field: expr, $fieldty: tt)),*}) => { {
  91                 use util::ser::BigSize;
  92                 let len = {
  93                         #[allow(unused_mut)]
  94                         let mut len = ::util::ser::LengthCalculatingWriter(0);
  95                         $(
  96                                 get_varint_length_prefixed_tlv_length!(len, $type, $field, $fieldty);
  97                         )*
  98                         len.0
  99                 };
 100                 BigSize(len as u64).write($stream)?;
 101                 encode_tlv_stream!($stream, { $(($type, $field, $fieldty)),* });
 102         } }
 103 }
 104
 105 macro_rules! check_tlv_order {
 106         ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, (default_value, $default: expr)) => {{
 107                 #[allow(unused_comparisons)] // Note that $type may be 0 making the second comparison always true
 108                 let invalid_order = ($last_seen_type.is_none() || $last_seen_type.unwrap() < $type) && $typ.0 > $type;
 109                 if invalid_order {
 110                         $field = $default.into();
 111                 }
 112         }};
 113         ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, required) => {{
 114                 #[allow(unused_comparisons)] // Note that $type may be 0 making the second comparison always true
 115                 let invalid_order = ($last_seen_type.is_none() || $last_seen_type.unwrap() < $type) && $typ.0 > $type;
 116                 if invalid_order {
 117                         return Err(DecodeError::InvalidValue);
 118                 }
 119         }};
 120         ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, option) => {{
 121                 // no-op
 122         }};
 123         ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, vec_type) => {{
 124                 // no-op
 125         }};
 126         ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, ignorable) => {{
 127                 // no-op
 128         }};
 129         ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, (option: $trait: ident $(, $read_arg: expr)?)) => {{
 130                 // no-op
 131         }};
 132         ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, (tlv_record, $fieldty:tt)) => {{
 133                 // no-op
 134         }};
 135 }
 136
 137 macro_rules! check_missing_tlv {
 138         ($last_seen_type: expr, $type: expr, $field: ident, (default_value, $default: expr)) => {{
 139                 #[allow(unused_comparisons)] // Note that $type may be 0 making the second comparison always true
 140                 let missing_req_type = $last_seen_type.is_none() || $last_seen_type.unwrap() < $type;
 141                 if missing_req_type {
 142                         $field = $default.into();
 143                 }
 144         }};
 145         ($last_seen_type: expr, $type: expr, $field: ident, required) => {{
 146                 #[allow(unused_comparisons)] // Note that $type may be 0 making the second comparison always true
 147                 let missing_req_type = $last_seen_type.is_none() || $last_seen_type.unwrap() < $type;
 148                 if missing_req_type {
 149                         return Err(DecodeError::InvalidValue);
 150                 }
 151         }};
 152         ($last_seen_type: expr, $type: expr, $field: ident, vec_type) => {{
 153                 // no-op
 154         }};
 155         ($last_seen_type: expr, $type: expr, $field: ident, option) => {{
 156                 // no-op
 157         }};
 158         ($last_seen_type: expr, $type: expr, $field: ident, ignorable) => {{
 159                 // no-op
 160         }};
 161         ($last_seen_type: expr, $type: expr, $field: ident, (option: $trait: ident $(, $read_arg: expr)?)) => {{
 162                 // no-op
 163         }};
 164         ($last_seen_type: expr, $type: expr, $field: ident, (tlv_record, $fieldty:tt)) => {{
 165                 // no-op
 166         }};
 167 }
 168
 169 macro_rules! decode_tlv {
 170         ($reader: expr, $field: ident, (default_value, $default: expr)) => {{
 171                 decode_tlv!($reader, $field, required)
 172         }};
 173         ($reader: expr, $field: ident, required) => {{
 174                 $field = ser::Readable::read(&mut $reader)?;
 175         }};
 176         ($reader: expr, $field: ident, vec_type) => {{
 177                 let f: ::util::ser::VecReadWrapper<_> = ser::Readable::read(&mut $reader)?;
 178                 $field = Some(f.0);
 179         }};
 180         ($reader: expr, $field: ident, option) => {{
 181                 $field = Some(ser::Readable::read(&mut $reader)?);
 182         }};
 183         ($reader: expr, $field: ident, ignorable) => {{
 184                 $field = ser::MaybeReadable::read(&mut $reader)?;
 185         }};
 186         ($reader: expr, $field: ident, (option: $trait: ident $(, $read_arg: expr)?)) => {{
 187                 $field = Some($trait::read(&mut $reader $(, $read_arg)*)?);
 188         }};
 189         ($reader: expr, $field: ident, (tlv_record, $fieldty:tt)) => {{
 190                 $field = {
 191                         let field: encoded_tlv_record_type!($fieldty) = ser::Readable::read(&mut $reader)?;
 192                         Some(field.into())
 193                 };
 194         }};
 195 }
 196
 197 macro_rules! decode_tlv_stream {
 198         ($stream: expr, {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}) => { {
 199                 use ln::msgs::DecodeError;
 200                 let mut last_seen_type: Option<u64> = None;
 201                 let mut stream_ref = $stream;
 202                 'tlv_read: loop {
 203                         use util::ser;
 204
 205                         // First decode the type of this TLV:
 206                         let typ: ser::BigSize = {
 207                                 // We track whether any bytes were read during the consensus_decode call to
 208                                 // determine whether we should break or return ShortRead if we get an
 209                                 // UnexpectedEof. This should in every case be largely cosmetic, but its nice to
 210                                 // pass the TLV test vectors exactly, which requre this distinction.
 211                                 let mut tracking_reader = ser::ReadTrackingReader::new(&mut stream_ref);
 212                                 match ser::Readable::read(&mut tracking_reader) {
 213                                         Err(DecodeError::ShortRead) => {
 214                                                 if !tracking_reader.have_read {
 215                                                         break 'tlv_read;
 216                                                 } else {
 217                                                         return Err(DecodeError::ShortRead);
 218                                                 }
 219                                         },
 220                                         Err(e) => return Err(e),
 221                                         Ok(t) => t,
 222                                 }
 223                         };
 224
 225                         // Types must be unique and monotonically increasing:
 226                         match last_seen_type {
 227                                 Some(t) if typ.0 <= t => {
 228                                         return Err(DecodeError::InvalidValue);
 229                                 },
 230                                 _ => {},
 231                         }
 232                         // As we read types, make sure we hit every required type:
 233                         $({
 234                                 check_tlv_order!(last_seen_type, typ, $type, $field, $fieldty);
 235                         })*
 236                         last_seen_type = Some(typ.0);
 237
 238                         // Finally, read the length and value itself:
 239                         let length: ser::BigSize = ser::Readable::read(&mut stream_ref)?;
 240                         let mut s = ser::FixedLengthReader::new(&mut stream_ref, length.0);
 241                         match typ.0 {
 242                                 $($type => {
 243                                         decode_tlv!(s, $field, $fieldty);
 244                                         if s.bytes_remain() {
 245                                                 s.eat_remaining()?; // Return ShortRead if there's actually not enough bytes
 246                                                 return Err(DecodeError::InvalidValue);
 247                                         }
 248                                 },)*
 249                                 x if x % 2 == 0 => {
 250                                         return Err(DecodeError::UnknownRequiredFeature);
 251                                 },
 252                                 _ => {},
 253                         }
 254                         s.eat_remaining()?;
 255                 }
 256                 // Make sure we got to each required type after we've read every TLV:
 257                 $({
 258                         check_missing_tlv!(last_seen_type, $type, $field, $fieldty);
 259                 })*
 260         } }
 261 }
 262
 263 macro_rules! impl_writeable_msg {
 264         ($st:ident, {$($field:ident),* $(,)*}, {$(($type: expr, $tlvfield: ident, $fieldty: tt)),* $(,)*}) => {
 265                 impl ::util::ser::Writeable for $st {
 266                         fn write<W: ::util::ser::Writer>(&self, w: &mut W) -> Result<(), $crate::io::Error> {
 267                                 $( self.$field.write(w)?; )*
 268                                 encode_tlv_stream!(w, {$(($type, self.$tlvfield, $fieldty)),*});
 269                                 Ok(())
 270                         }
 271                 }
 272                 impl ::util::ser::Readable for $st {
 273                         fn read<R: $crate::io::Read>(r: &mut R) -> Result<Self, ::ln::msgs::DecodeError> {
 274                                 $(let $field = ::util::ser::Readable::read(r)?;)*
 275                                 $(init_tlv_field_var!($tlvfield, $fieldty);)*
 276                                 decode_tlv_stream!(r, {$(($type, $tlvfield, $fieldty)),*});
 277                                 Ok(Self {
 278                                         $($field),*,
 279                                         $($tlvfield),*
 280                                 })
 281                         }
 282                 }
 283         }
 284 }
 285
 286 macro_rules! impl_writeable {
 287         ($st:ident, {$($field:ident),*}) => {
 288                 impl ::util::ser::Writeable for $st {
 289                         fn write<W: ::util::ser::Writer>(&self, w: &mut W) -> Result<(), $crate::io::Error> {
 290                                 $( self.$field.write(w)?; )*
 291                                 Ok(())
 292                         }
 293
 294                         #[inline]
 295                         fn serialized_length(&self) -> usize {
 296                                 let mut len_calc = 0;
 297                                 $( len_calc += self.$field.serialized_length(); )*
 298                                 return len_calc;
 299                         }
 300                 }
 301
 302                 impl ::util::ser::Readable for $st {
 303                         fn read<R: $crate::io::Read>(r: &mut R) -> Result<Self, ::ln::msgs::DecodeError> {
 304                                 Ok(Self {
 305                                         $($field: ::util::ser::Readable::read(r)?),*
 306                                 })
 307                         }
 308                 }
 309         }
 310 }
 311
 312 /// Write out two bytes to indicate the version of an object.
 313 /// $this_version represents a unique version of a type. Incremented whenever the type's
 314 ///               serialization format has changed or has a new interpretation. Used by a type's
 315 ///               reader to determine how to interpret fields or if it can understand a serialized
 316 ///               object.
 317 /// $min_version_that_can_read_this is the minimum reader version which can understand this
 318 ///                                 serialized object. Previous versions will simply err with a
 319 ///                                 DecodeError::UnknownVersion.
 320 ///
 321 /// Updates to either $this_version or $min_version_that_can_read_this should be included in
 322 /// release notes.
 323 ///
 324 /// Both version fields can be specific to this type of object.
 325 macro_rules! write_ver_prefix {
 326         ($stream: expr, $this_version: expr, $min_version_that_can_read_this: expr) => {
 327                 $stream.write_all(&[$this_version; 1])?;
 328                 $stream.write_all(&[$min_version_that_can_read_this; 1])?;
 329         }
 330 }
 331
 332 /// Writes out a suffix to an object which contains potentially backwards-compatible, optional
 333 /// fields which old nodes can happily ignore.
 334 ///
 335 /// It is written out in TLV format and, as with all TLV fields, unknown even fields cause a
 336 /// DecodeError::UnknownRequiredFeature error, with unknown odd fields ignored.
 337 ///
 338 /// This is the preferred method of adding new fields that old nodes can ignore and still function
 339 /// correctly.
 340 macro_rules! write_tlv_fields {
 341         ($stream: expr, {$(($type: expr, $field: expr, $fieldty: tt)),* $(,)*}) => {
 342                 encode_varint_length_prefixed_tlv!($stream, {$(($type, $field, $fieldty)),*})
 343         }
 344 }
 345
 346 /// Reads a prefix added by write_ver_prefix!(), above. Takes the current version of the
 347 /// serialization logic for this object. This is compared against the
 348 /// $min_version_that_can_read_this added by write_ver_prefix!().
 349 macro_rules! read_ver_prefix {
 350         ($stream: expr, $this_version: expr) => { {
 351                 let ver: u8 = Readable::read($stream)?;
 352                 let min_ver: u8 = Readable::read($stream)?;
 353                 if min_ver > $this_version {
 354                         return Err(DecodeError::UnknownVersion);
 355                 }
 356                 ver
 357         } }
 358 }
 359
 360 /// Reads a suffix added by write_tlv_fields.
 361 macro_rules! read_tlv_fields {
 362         ($stream: expr, {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}) => { {
 363                 let tlv_len: ::util::ser::BigSize = ::util::ser::Readable::read($stream)?;
 364                 let mut rd = ::util::ser::FixedLengthReader::new($stream, tlv_len.0);
 365                 decode_tlv_stream!(&mut rd, {$(($type, $field, $fieldty)),*});
 366                 rd.eat_remaining().map_err(|_| ::ln::msgs::DecodeError::ShortRead)?;
 367         } }
 368 }
 369
 370 macro_rules! init_tlv_based_struct_field {
 371         ($field: ident, (default_value, $default: expr)) => {
 372                 $field.0.unwrap()
 373         };
 374         ($field: ident, option) => {
 375                 $field
 376         };
 377         ($field: ident, required) => {
 378                 $field.0.unwrap()
 379         };
 380         ($field: ident, vec_type) => {
 381                 $field.unwrap()
 382         };
 383 }
 384
 385 macro_rules! init_tlv_field_var {
 386         ($field: ident, (default_value, $default: expr)) => {
 387                 let mut $field = ::util::ser::OptionDeserWrapper(None);
 388         };
 389         ($field: ident, required) => {
 390                 let mut $field = ::util::ser::OptionDeserWrapper(None);
 391         };
 392         ($field: ident, vec_type) => {
 393                 let mut $field = Some(Vec::new());
 394         };
 395         ($field: ident, option) => {
 396                 let mut $field = None;
 397         };
 398         ($field: ident, tlv_record) => {
 399                 let mut $field = None;
 400         };
 401 }
 402
 403 /// Implements Readable/Writeable for a struct storing it as a set of TLVs
 404 /// If $fieldty is `required`, then $field is a required field that is not an Option nor a Vec.
 405 /// If $fieldty is `option`, then $field is optional field.
 406 /// if $fieldty is `vec_type`, then $field is a Vec, which needs to have its individual elements
 407 /// serialized.
 408 macro_rules! impl_writeable_tlv_based {
 409         ($st: ident, {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}) => {
 410                 impl ::util::ser::Writeable for $st {
 411                         fn write<W: ::util::ser::Writer>(&self, writer: &mut W) -> Result<(), $crate::io::Error> {
 412                                 write_tlv_fields!(writer, {
 413                                         $(($type, self.$field, $fieldty)),*
 414                                 });
 415                                 Ok(())
 416                         }
 417
 418                         #[inline]
 419                         fn serialized_length(&self) -> usize {
 420                                 use util::ser::BigSize;
 421                                 let len = {
 422                                         #[allow(unused_mut)]
 423                                         let mut len = ::util::ser::LengthCalculatingWriter(0);
 424                                         $(
 425                                                 get_varint_length_prefixed_tlv_length!(len, $type, self.$field, $fieldty);
 426                                         )*
 427                                         len.0
 428                                 };
 429                                 let mut len_calc = ::util::ser::LengthCalculatingWriter(0);
 430                                 BigSize(len as u64).write(&mut len_calc).expect("No in-memory data may fail to serialize");
 431                                 len + len_calc.0
 432                         }
 433                 }
 434
 435                 impl ::util::ser::Readable for $st {
 436                         fn read<R: $crate::io::Read>(reader: &mut R) -> Result<Self, ::ln::msgs::DecodeError> {
 437                                 $(
 438                                         init_tlv_field_var!($field, $fieldty);
 439                                 )*
 440                                 read_tlv_fields!(reader, {
 441                                         $(($type, $field, $fieldty)),*
 442                                 });
 443                                 Ok(Self {
 444                                         $(
 445                                                 $field: init_tlv_based_struct_field!($field, $fieldty)
 446                                         ),*
 447                                 })
 448                         }
 449                 }
 450         }
 451 }
 452
 453 /// Defines a struct for a TLV stream and a similar struct using references for non-primitive types,
 454 /// implementing [`Readable`] for the former and [`Writeable`] for the latter. Useful as an
 455 /// intermediary format when reading or writing a type encoded as a TLV stream. Note that each field
 456 /// representing a TLV record has its type wrapped with an [`Option`].
 457 ///
 458 /// [`Readable`]: crate::util::ser::Readable
 459 /// [`Writeable`]: crate::util::ser::Writeable
 460 macro_rules! tlv_stream {
 461         ($name:ident, $nameref:ident, {
 462                 $(($type:expr, $field:ident : $fieldty:tt)),* $(,)*
 463         }) => {
 464                 #[derive(Debug)]
 465                 struct $name {
 466                         $(
 467                                 $field: Option<tlv_record_type!($fieldty)>,
 468                         )*
 469                 }
 470
 471                 pub(crate) struct $nameref<'a> {
 472                         $(
 473                                 pub(crate) $field: Option<tlv_record_ref_type!($fieldty)>,
 474                         )*
 475                 }
 476
 477                 impl<'a> ::util::ser::Writeable for $nameref<'a> {
 478                         fn write<W: ::util::ser::Writer>(&self, writer: &mut W) -> Result<(), $crate::io::Error> {
 479                                 encode_tlv_stream!(writer, {
 480                                         $(($type, self.$field, (tlv_record, $fieldty))),*
 481                                 });
 482                                 Ok(())
 483                         }
 484                 }
 485
 486                 impl ::util::ser::Readable for $name {
 487                         fn read<R: $crate::io::Read>(reader: &mut R) -> Result<Self, ::ln::msgs::DecodeError> {
 488                                 $(
 489                                         init_tlv_field_var!($field, tlv_record);
 490                                 )*
 491                                 decode_tlv_stream!(reader, {
 492                                         $(($type, $field, (tlv_record, $fieldty))),*
 493                                 });
 494
 495                                 Ok(Self {
 496                                         $(
 497                                                 $field: $field
 498                                         ),*
 499                                 })
 500                         }
 501                 }
 502         }
 503 }
 504
 505 macro_rules! tlv_record_type {
 506         (($type:ty, $wrapper:ident)) => {
 507                 $type
 508         };
 509         ($type:ty) => {
 510                 $type
 511         };
 512 }
 513
 514 macro_rules! tlv_record_ref_type {
 515         (u8) => {
 516                 u8
 517         };
 518         (char) => {
 519                 char
 520         };
 521         (($type:ty, HighZeroBytesDroppedBigSize)) => {
 522                 $type
 523         };
 524         (($type:ty, $wrapper:ident)) => {
 525                 &'a $type
 526         };
 527         ($type:ty) => {
 528                 &'a $type
 529         };
 530 }
 531
 532 macro_rules! encoded_tlv_record_type {
 533         (($type:ty, $wrapper:ident)) => {
 534                 $wrapper<$type>
 535         };
 536         ($type:ty) => {
 537                 $type
 538         };
 539 }
 540
 541 macro_rules! encoded_tlv_record_ref_type {
 542         (u8) => {
 543                 u8
 544         };
 545         (char) => {
 546                 char
 547         };
 548         (($type:ty, HighZeroBytesDroppedBigSize)) => {
 549                 HighZeroBytesDroppedBigSize<$type>
 550         };
 551         (($type:ty, $wrapper:ident)) => {
 552                 $wrapper<&$type>
 553         };
 554         ($type:ty) => {
 555                 &$type
 556         };
 557 }
 558
 559 macro_rules! _impl_writeable_tlv_based_enum_common {
 560         ($st: ident, $(($variant_id: expr, $variant_name: ident) =>
 561                 {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}
 562         ),* $(,)*;
 563         $(($tuple_variant_id: expr, $tuple_variant_name: ident)),*  $(,)*) => {
 564                 impl ::util::ser::Writeable for $st {
 565                         fn write<W: ::util::ser::Writer>(&self, writer: &mut W) -> Result<(), $crate::io::Error> {
 566                                 match self {
 567                                         $($st::$variant_name { $(ref $field),* } => {
 568                                                 let id: u8 = $variant_id;
 569                                                 id.write(writer)?;
 570                                                 write_tlv_fields!(writer, {
 571                                                         $(($type, $field, $fieldty)),*
 572                                                 });
 573                                         }),*
 574                                         $($st::$tuple_variant_name (ref field) => {
 575                                                 let id: u8 = $tuple_variant_id;
 576                                                 id.write(writer)?;
 577                                                 field.write(writer)?;
 578                                         }),*
 579                                 }
 580                                 Ok(())
 581                         }
 582                 }
 583         }
 584 }
 585
 586 /// Implement MaybeReadable and Writeable for an enum, with struct variants stored as TLVs and
 587 /// tuple variants stored directly.
 588 ///
 589 /// This is largely identical to `impl_writeable_tlv_based_enum`, except that odd variants will
 590 /// return `Ok(None)` instead of `Err(UnknownRequiredFeature)`. It should generally be preferred
 591 /// when `MaybeReadable` is practical instead of just `Readable` as it provides an upgrade path for
 592 /// new variants to be added which are simply ignored by existing clients.
 593 macro_rules! impl_writeable_tlv_based_enum_upgradable {
 594         ($st: ident, $(($variant_id: expr, $variant_name: ident) =>
 595                 {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}
 596         ),* $(,)*
 597         $(;
 598         $(($tuple_variant_id: expr, $tuple_variant_name: ident)),*  $(,)*)*) => {
 599                 _impl_writeable_tlv_based_enum_common!($st,
 600                         $(($variant_id, $variant_name) => {$(($type, $field, $fieldty)),*}),*;
 601                         $($(($tuple_variant_id, $tuple_variant_name)),*)*);
 602
 603                 impl ::util::ser::MaybeReadable for $st {
 604                         fn read<R: $crate::io::Read>(reader: &mut R) -> Result<Option<Self>, ::ln::msgs::DecodeError> {
 605                                 let id: u8 = ::util::ser::Readable::read(reader)?;
 606                                 match id {
 607                                         $($variant_id => {
 608                                                 // Because read_tlv_fields creates a labeled loop, we cannot call it twice
 609                                                 // in the same function body. Instead, we define a closure and call it.
 610                                                 let f = || {
 611                                                         $(
 612                                                                 init_tlv_field_var!($field, $fieldty);
 613                                                         )*
 614                                                         read_tlv_fields!(reader, {
 615                                                                 $(($type, $field, $fieldty)),*
 616                                                         });
 617                                                         Ok(Some($st::$variant_name {
 618                                                                 $(
 619                                                                         $field: init_tlv_based_struct_field!($field, $fieldty)
 620                                                                 ),*
 621                                                         }))
 622                                                 };
 623                                                 f()
 624                                         }),*
 625                                         $($($tuple_variant_id => {
 626                                                 Ok(Some($st::$tuple_variant_name(Readable::read(reader)?)))
 627                                         }),*)*
 628                                         _ if id % 2 == 1 => Ok(None),
 629                                         _ => Err(DecodeError::UnknownRequiredFeature),
 630                                 }
 631                         }
 632                 }
 633
 634         }
 635 }
 636
 637 /// Implement Readable and Writeable for an enum, with struct variants stored as TLVs and tuple
 638 /// variants stored directly.
 639 /// The format is, for example
 640 /// impl_writeable_tlv_based_enum!(EnumName,
 641 ///   (0, StructVariantA) => {(0, required_variant_field, required), (1, optional_variant_field, option)},
 642 ///   (1, StructVariantB) => {(0, variant_field_a, required), (1, variant_field_b, required), (2, variant_vec_field, vec_type)};
 643 ///   (2, TupleVariantA), (3, TupleVariantB),
 644 /// );
 645 /// The type is written as a single byte, followed by any variant data.
 646 /// Attempts to read an unknown type byte result in DecodeError::UnknownRequiredFeature.
 647 macro_rules! impl_writeable_tlv_based_enum {
 648         ($st: ident, $(($variant_id: expr, $variant_name: ident) =>
 649                 {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}
 650         ),* $(,)*;
 651         $(($tuple_variant_id: expr, $tuple_variant_name: ident)),*  $(,)*) => {
 652                 _impl_writeable_tlv_based_enum_common!($st,
 653                         $(($variant_id, $variant_name) => {$(($type, $field, $fieldty)),*}),*;
 654                         $(($tuple_variant_id, $tuple_variant_name)),*);
 655
 656                 impl ::util::ser::Readable for $st {
 657                         fn read<R: $crate::io::Read>(reader: &mut R) -> Result<Self, ::ln::msgs::DecodeError> {
 658                                 let id: u8 = ::util::ser::Readable::read(reader)?;
 659                                 match id {
 660                                         $($variant_id => {
 661                                                 // Because read_tlv_fields creates a labeled loop, we cannot call it twice
 662                                                 // in the same function body. Instead, we define a closure and call it.
 663                                                 let f = || {
 664                                                         $(
 665                                                                 init_tlv_field_var!($field, $fieldty);
 666                                                         )*
 667                                                         read_tlv_fields!(reader, {
 668                                                                 $(($type, $field, $fieldty)),*
 669                                                         });
 670                                                         Ok($st::$variant_name {
 671                                                                 $(
 672                                                                         $field: init_tlv_based_struct_field!($field, $fieldty)
 673                                                                 ),*
 674                                                         })
 675                                                 };
 676                                                 f()
 677                                         }),*
 678                                         $($tuple_variant_id => {
 679                                                 Ok($st::$tuple_variant_name(Readable::read(reader)?))
 680                                         }),*
 681                                         _ => {
 682                                                 Err(DecodeError::UnknownRequiredFeature)
 683                                         },
 684                                 }
 685                         }
 686                 }
 687         }
 688 }
 689
 690 #[cfg(test)]
 691 mod tests {
 692         use io::{self, Cursor};
 693         use prelude::*;
 694         use ln::msgs::DecodeError;
 695         use util::ser::{Writeable, HighZeroBytesDroppedBigSize, VecWriter};
 696         use bitcoin::secp256k1::PublicKey;
 697
 698         // The BOLT TLV test cases don't include any tests which use our "required-value" logic since
 699         // the encoding layer in the BOLTs has no such concept, though it makes our macros easier to
 700         // work with so they're baked into the decoder. Thus, we have a few additional tests below
 701         fn tlv_reader(s: &[u8]) -> Result<(u64, u32, Option<u32>), DecodeError> {
 702                 let mut s = Cursor::new(s);
 703                 let mut a: u64 = 0;
 704                 let mut b: u32 = 0;
 705                 let mut c: Option<u32> = None;
 706                 decode_tlv_stream!(&mut s, {(2, a, required), (3, b, required), (4, c, option)});
 707                 Ok((a, b, c))
 708         }
 709
 710         #[test]
 711         fn tlv_v_short_read() {
 712                 // We only expect a u32 for type 3 (which we are given), but the L says its 8 bytes.
 713                 if let Err(DecodeError::ShortRead) = tlv_reader(&::hex::decode(
 714                                 concat!("0100", "0208deadbeef1badbeef", "0308deadbeef")
 715                                 ).unwrap()[..]) {
 716                 } else { panic!(); }
 717         }
 718
 719         #[test]
 720         fn tlv_types_out_of_order() {
 721                 if let Err(DecodeError::InvalidValue) = tlv_reader(&::hex::decode(
 722                                 concat!("0100", "0304deadbeef", "0208deadbeef1badbeef")
 723                                 ).unwrap()[..]) {
 724                 } else { panic!(); }
 725                 // ...even if its some field we don't understand
 726                 if let Err(DecodeError::InvalidValue) = tlv_reader(&::hex::decode(
 727                                 concat!("0208deadbeef1badbeef", "0100", "0304deadbeef")
 728                                 ).unwrap()[..]) {
 729                 } else { panic!(); }
 730         }
 731
 732         #[test]
 733         fn tlv_req_type_missing_or_extra() {
 734                 // It's also bad if they included even fields we don't understand
 735                 if let Err(DecodeError::UnknownRequiredFeature) = tlv_reader(&::hex::decode(
 736                                 concat!("0100", "0208deadbeef1badbeef", "0304deadbeef", "0600")
 737                                 ).unwrap()[..]) {
 738                 } else { panic!(); }
 739                 // ... or if they're missing fields we need
 740                 if let Err(DecodeError::InvalidValue) = tlv_reader(&::hex::decode(
 741                                 concat!("0100", "0208deadbeef1badbeef")
 742                                 ).unwrap()[..]) {
 743                 } else { panic!(); }
 744                 // ... even if that field is even
 745                 if let Err(DecodeError::InvalidValue) = tlv_reader(&::hex::decode(
 746                                 concat!("0304deadbeef", "0500")
 747                                 ).unwrap()[..]) {
 748                 } else { panic!(); }
 749         }
 750
 751         #[test]
 752         fn tlv_simple_good_cases() {
 753                 assert_eq!(tlv_reader(&::hex::decode(
 754                                 concat!("0208deadbeef1badbeef", "03041bad1dea")
 755                                 ).unwrap()[..]).unwrap(),
 756                         (0xdeadbeef1badbeef, 0x1bad1dea, None));
 757                 assert_eq!(tlv_reader(&::hex::decode(
 758                                 concat!("0208deadbeef1badbeef", "03041bad1dea", "040401020304")
 759                                 ).unwrap()[..]).unwrap(),
 760                         (0xdeadbeef1badbeef, 0x1bad1dea, Some(0x01020304)));
 761         }
 762
 763         // BOLT TLV test cases
 764         fn tlv_reader_n1(s: &[u8]) -> Result<(Option<HighZeroBytesDroppedBigSize<u64>>, Option<u64>, Option<(PublicKey, u64, u64)>, Option<u16>), DecodeError> {
 765                 let mut s = Cursor::new(s);
 766                 let mut tlv1: Option<HighZeroBytesDroppedBigSize<u64>> = None;
 767                 let mut tlv2: Option<u64> = None;
 768                 let mut tlv3: Option<(PublicKey, u64, u64)> = None;
 769                 let mut tlv4: Option<u16> = None;
 770                 decode_tlv_stream!(&mut s, {(1, tlv1, option), (2, tlv2, option), (3, tlv3, option), (254, tlv4, option)});
 771                 Ok((tlv1, tlv2, tlv3, tlv4))
 772         }
 773
 774         #[test]
 775         fn bolt_tlv_bogus_stream() {
 776                 macro_rules! do_test {
 777                         ($stream: expr, $reason: ident) => {
 778                                 if let Err(DecodeError::$reason) = tlv_reader_n1(&::hex::decode($stream).unwrap()[..]) {
 779                                 } else { panic!(); }
 780                         }
 781                 }
 782
 783                 // TLVs from the BOLT test cases which should not decode as either n1 or n2
 784                 do_test!(concat!("fd01"), ShortRead);
 785                 do_test!(concat!("fd0001", "00"), InvalidValue);
 786                 do_test!(concat!("fd0101"), ShortRead);
 787                 do_test!(concat!("0f", "fd"), ShortRead);
 788                 do_test!(concat!("0f", "fd26"), ShortRead);
 789                 do_test!(concat!("0f", "fd2602"), ShortRead);
 790                 do_test!(concat!("0f", "fd0001", "00"), InvalidValue);
 791                 do_test!(concat!("0f", "fd0201", "000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"), ShortRead);
 792
 793                 do_test!(concat!("12", "00"), UnknownRequiredFeature);
 794                 do_test!(concat!("fd0102", "00"), UnknownRequiredFeature);
 795                 do_test!(concat!("fe01000002", "00"), UnknownRequiredFeature);
 796                 do_test!(concat!("ff0100000000000002", "00"), UnknownRequiredFeature);
 797         }
 798
 799         #[test]
 800         fn bolt_tlv_bogus_n1_stream() {
 801                 macro_rules! do_test {
 802                         ($stream: expr, $reason: ident) => {
 803                                 if let Err(DecodeError::$reason) = tlv_reader_n1(&::hex::decode($stream).unwrap()[..]) {
 804                                 } else { panic!(); }
 805                         }
 806                 }
 807
 808                 // TLVs from the BOLT test cases which should not decode as n1
 809                 do_test!(concat!("01", "09", "ffffffffffffffffff"), InvalidValue);
 810                 do_test!(concat!("01", "01", "00"), InvalidValue);
 811                 do_test!(concat!("01", "02", "0001"), InvalidValue);
 812                 do_test!(concat!("01", "03", "000100"), InvalidValue);
 813                 do_test!(concat!("01", "04", "00010000"), InvalidValue);
 814                 do_test!(concat!("01", "05", "0001000000"), InvalidValue);
 815                 do_test!(concat!("01", "06", "000100000000"), InvalidValue);
 816                 do_test!(concat!("01", "07", "00010000000000"), InvalidValue);
 817                 do_test!(concat!("01", "08", "0001000000000000"), InvalidValue);
 818                 do_test!(concat!("02", "07", "01010101010101"), ShortRead);
 819                 do_test!(concat!("02", "09", "010101010101010101"), InvalidValue);
 820                 do_test!(concat!("03", "21", "023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb"), ShortRead);
 821                 do_test!(concat!("03", "29", "023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb0000000000000001"), ShortRead);
 822                 do_test!(concat!("03", "30", "023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb000000000000000100000000000001"), ShortRead);
 823                 do_test!(concat!("03", "31", "043da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb00000000000000010000000000000002"), InvalidValue);
 824                 do_test!(concat!("03", "32", "023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb0000000000000001000000000000000001"), InvalidValue);
 825                 do_test!(concat!("fd00fe", "00"), ShortRead);
 826                 do_test!(concat!("fd00fe", "01", "01"), ShortRead);
 827                 do_test!(concat!("fd00fe", "03", "010101"), InvalidValue);
 828                 do_test!(concat!("00", "00"), UnknownRequiredFeature);
 829
 830                 do_test!(concat!("02", "08", "0000000000000226", "01", "01", "2a"), InvalidValue);
 831                 do_test!(concat!("02", "08", "0000000000000231", "02", "08", "0000000000000451"), InvalidValue);
 832                 do_test!(concat!("1f", "00", "0f", "01", "2a"), InvalidValue);
 833                 do_test!(concat!("1f", "00", "1f", "01", "2a"), InvalidValue);
 834
 835                 // The last BOLT test modified to not require creating a new decoder for one trivial test.
 836                 do_test!(concat!("ffffffffffffffffff", "00", "01", "00"), InvalidValue);
 837         }
 838
 839         #[test]
 840         fn bolt_tlv_valid_n1_stream() {
 841                 macro_rules! do_test {
 842                         ($stream: expr, $tlv1: expr, $tlv2: expr, $tlv3: expr, $tlv4: expr) => {
 843                                 if let Ok((tlv1, tlv2, tlv3, tlv4)) = tlv_reader_n1(&::hex::decode($stream).unwrap()[..]) {
 844                                         assert_eq!(tlv1.map(|v| v.0), $tlv1);
 845                                         assert_eq!(tlv2, $tlv2);
 846                                         assert_eq!(tlv3, $tlv3);
 847                                         assert_eq!(tlv4, $tlv4);
 848                                 } else { panic!(); }
 849                         }
 850                 }
 851
 852                 do_test!(concat!(""), None, None, None, None);
 853                 do_test!(concat!("21", "00"), None, None, None, None);
 854                 do_test!(concat!("fd0201", "00"), None, None, None, None);
 855                 do_test!(concat!("fd00fd", "00"), None, None, None, None);
 856                 do_test!(concat!("fd00ff", "00"), None, None, None, None);
 857                 do_test!(concat!("fe02000001", "00"), None, None, None, None);
 858                 do_test!(concat!("ff0200000000000001", "00"), None, None, None, None);
 859
 860                 do_test!(concat!("01", "00"), Some(0), None, None, None);
 861                 do_test!(concat!("01", "01", "01"), Some(1), None, None, None);
 862                 do_test!(concat!("01", "02", "0100"), Some(256), None, None, None);
 863                 do_test!(concat!("01", "03", "010000"), Some(65536), None, None, None);
 864                 do_test!(concat!("01", "04", "01000000"), Some(16777216), None, None, None);
 865                 do_test!(concat!("01", "05", "0100000000"), Some(4294967296), None, None, None);
 866                 do_test!(concat!("01", "06", "010000000000"), Some(1099511627776), None, None, None);
 867                 do_test!(concat!("01", "07", "01000000000000"), Some(281474976710656), None, None, None);
 868                 do_test!(concat!("01", "08", "0100000000000000"), Some(72057594037927936), None, None, None);
 869                 do_test!(concat!("02", "08", "0000000000000226"), None, Some((0 << 30) | (0 << 5) | (550 << 0)), None, None);
 870                 do_test!(concat!("03", "31", "023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb00000000000000010000000000000002"),
 871                         None, None, Some((
 872                                 PublicKey::from_slice(&::hex::decode("023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb").unwrap()[..]).unwrap(), 1, 2)),
 873                         None);
 874                 do_test!(concat!("fd00fe", "02", "0226"), None, None, None, Some(550));
 875         }
 876
 877         fn do_simple_test_tlv_write() -> Result<(), io::Error> {
 878                 let mut stream = VecWriter(Vec::new());
 879
 880                 stream.0.clear();
 881                 encode_varint_length_prefixed_tlv!(&mut stream, {(1, 1u8, required), (42, None::<u64>, option)});
 882                 assert_eq!(stream.0, ::hex::decode("03010101").unwrap());
 883
 884                 stream.0.clear();
 885                 encode_varint_length_prefixed_tlv!(&mut stream, {(1, Some(1u8), option)});
 886                 assert_eq!(stream.0, ::hex::decode("03010101").unwrap());
 887
 888                 stream.0.clear();
 889                 encode_varint_length_prefixed_tlv!(&mut stream, {(4, 0xabcdu16, required), (42, None::<u64>, option)});
 890                 assert_eq!(stream.0, ::hex::decode("040402abcd").unwrap());
 891
 892                 stream.0.clear();
 893                 encode_varint_length_prefixed_tlv!(&mut stream, {(42, None::<u64>, option), (0xff, 0xabcdu16, required)});
 894                 assert_eq!(stream.0, ::hex::decode("06fd00ff02abcd").unwrap());
 895
 896                 stream.0.clear();
 897                 encode_varint_length_prefixed_tlv!(&mut stream, {(0, 1u64, required), (42, None::<u64>, option), (0xff, HighZeroBytesDroppedBigSize(0u64), required)});
 898                 assert_eq!(stream.0, ::hex::decode("0e00080000000000000001fd00ff00").unwrap());
 899
 900                 stream.0.clear();
 901                 encode_varint_length_prefixed_tlv!(&mut stream, {(0, Some(1u64), option), (0xff, HighZeroBytesDroppedBigSize(0u64), required)});
 902                 assert_eq!(stream.0, ::hex::decode("0e00080000000000000001fd00ff00").unwrap());
 903
 904                 Ok(())
 905         }
 906
 907         #[test]
 908         fn simple_test_tlv_write() {
 909                 do_simple_test_tlv_write().unwrap();
 910         }
 911 }