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