_ 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, $field: expr)),*}, {$(($optional_type: expr, $optional_field: expr)),*}) => { {
  12                 #[allow(unused_imports)]
  13                 use util::ser::BigSize;
  14                 // Fields must be serialized in order, so we have to potentially switch between optional
  15                 // fields and normal fields while serializing. Thus, we end up having to loop over the type
  16                 // counts.
  17                 // Sadly, while LLVM does appear smart enough to make `max_field` a constant, it appears to
  18                 // refuse to unroll the loop. If we have enough entries that this is slow we can revisit
  19                 // this design in the future.
  20                 #[allow(unused_mut)]
  21                 let mut max_field: u64 = 0;
  22                 $(
  23                         if $type >= max_field { max_field = $type + 1; }
  24                 )*
  25                 $(
  26                         if $optional_type >= max_field { max_field = $optional_type + 1; }
  27                 )*
  28                 #[allow(unused_variables)]
  29                 for i in 0..max_field {
  30                         $(
  31                                 if i == $type {
  32                                         BigSize($type).write($stream)?;
  33                                         BigSize($field.serialized_length() as u64).write($stream)?;
  34                                         $field.write($stream)?;
  35                                 }
  36                         )*
  37                         $(
  38                                 if i == $optional_type {
  39                                         if let Some(ref field) = $optional_field {
  40                                                 BigSize($optional_type).write($stream)?;
  41                                                 BigSize(field.serialized_length() as u64).write($stream)?;
  42                                                 field.write($stream)?;
  43                                         }
  44                                 }
  45                         )*
  46                 }
  47         } }
  48 }
  49
  50 macro_rules! get_varint_length_prefixed_tlv_length {
  51         ({$(($type: expr, $field: expr)),*}, {$(($optional_type: expr, $optional_field: expr)),* $(,)*}) => { {
  52                 use util::ser::LengthCalculatingWriter;
  53                 #[allow(unused_mut)]
  54                 let mut len = LengthCalculatingWriter(0);
  55                 {
  56                         $(
  57                                 BigSize($type).write(&mut len).expect("No in-memory data may fail to serialize");
  58                                 let field_len = $field.serialized_length();
  59                                 BigSize(field_len as u64).write(&mut len).expect("No in-memory data may fail to serialize");
  60                                 len.0 += field_len;
  61                         )*
  62                         $(
  63                                 if let Some(ref field) = $optional_field {
  64                                         BigSize($optional_type).write(&mut len).expect("No in-memory data may fail to serialize");
  65                                         let field_len = field.serialized_length();
  66                                         BigSize(field_len as u64).write(&mut len).expect("No in-memory data may fail to serialize");
  67                                         len.0 += field_len;
  68                                 }
  69                         )*
  70                 }
  71                 len.0
  72         } }
  73 }
  74
  75 macro_rules! encode_varint_length_prefixed_tlv {
  76         ($stream: expr, {$(($type: expr, $field: expr)),*}, {$(($optional_type: expr, $optional_field: expr)),*}) => { {
  77                 use util::ser::BigSize;
  78                 let len = get_varint_length_prefixed_tlv_length!({ $(($type, $field)),* }, { $(($optional_type, $optional_field)),* });
  79                 BigSize(len as u64).write($stream)?;
  80                 encode_tlv!($stream, { $(($type, $field)),* }, { $(($optional_type, $optional_field)),* });
  81         } }
  82 }
  83
  84 macro_rules! decode_tlv {
  85         ($stream: expr, {$(($reqtype: expr, $reqfield: ident)),*}, {$(($type: expr, $field: ident)),*}) => { {
  86                 use ln::msgs::DecodeError;
  87                 let mut last_seen_type: Option<u64> = None;
  88                 'tlv_read: loop {
  89                         use util::ser;
  90
  91                         // First decode the type of this TLV:
  92                         let typ: ser::BigSize = {
  93                                 // We track whether any bytes were read during the consensus_decode call to
  94                                 // determine whether we should break or return ShortRead if we get an
  95                                 // UnexpectedEof. This should in every case be largely cosmetic, but its nice to
  96                                 // pass the TLV test vectors exactly, which requre this distinction.
  97                                 let mut tracking_reader = ser::ReadTrackingReader::new($stream);
  98                                 match ser::Readable::read(&mut tracking_reader) {
  99                                         Err(DecodeError::ShortRead) => {
 100                                                 if !tracking_reader.have_read {
 101                                                         break 'tlv_read
 102                                                 } else {
 103                                                         Err(DecodeError::ShortRead)?
 104                                                 }
 105                                         },
 106                                         Err(e) => Err(e)?,
 107                                         Ok(t) => t,
 108                                 }
 109                         };
 110
 111                         // Types must be unique and monotonically increasing:
 112                         match last_seen_type {
 113                                 Some(t) if typ.0 <= t => {
 114                                         Err(DecodeError::InvalidValue)?
 115                                 },
 116                                 _ => {},
 117                         }
 118                         // As we read types, make sure we hit every required type:
 119                         $({
 120                                 #[allow(unused_comparisons)] // Note that $reqtype may be 0 making the second comparison always true
 121                                 let invalid_order = (last_seen_type.is_none() || last_seen_type.unwrap() < $reqtype) && typ.0 > $reqtype;
 122                                 if invalid_order {
 123                                         Err(DecodeError::InvalidValue)?
 124                                 }
 125                         })*
 126                         last_seen_type = Some(typ.0);
 127
 128                         // Finally, read the length and value itself:
 129                         let length: ser::BigSize = Readable::read($stream)?;
 130                         let mut s = ser::FixedLengthReader::new($stream, length.0);
 131                         match typ.0 {
 132                                 $($reqtype => {
 133                                         $reqfield = ser::Readable::read(&mut s)?;
 134                                         if s.bytes_remain() {
 135                                                 s.eat_remaining()?; // Return ShortRead if there's actually not enough bytes
 136                                                 Err(DecodeError::InvalidValue)?
 137                                         }
 138                                 },)*
 139                                 $($type => {
 140                                         $field = Some(ser::Readable::read(&mut s)?);
 141                                         if s.bytes_remain() {
 142                                                 s.eat_remaining()?; // Return ShortRead if there's actually not enough bytes
 143                                                 Err(DecodeError::InvalidValue)?
 144                                         }
 145                                 },)*
 146                                 x if x % 2 == 0 => {
 147                                         Err(DecodeError::UnknownRequiredFeature)?
 148                                 },
 149                                 _ => {},
 150                         }
 151                         s.eat_remaining()?;
 152                 }
 153                 // Make sure we got to each required type after we've read every TLV:
 154                 $({
 155                         #[allow(unused_comparisons)] // Note that $reqtype may be 0 making the second comparison always true
 156                         let missing_req_type = last_seen_type.is_none() || last_seen_type.unwrap() < $reqtype;
 157                         if missing_req_type {
 158                                 Err(DecodeError::InvalidValue)?
 159                         }
 160                 })*
 161         } }
 162 }
 163
 164 macro_rules! impl_writeable {
 165         ($st:ident, $len: expr, {$($field:ident),*}) => {
 166                 impl ::util::ser::Writeable for $st {
 167                         fn write<W: ::util::ser::Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 168                                 if $len != 0 {
 169                                         w.size_hint($len);
 170                                 }
 171                                 #[cfg(any(test, feature = "fuzztarget"))]
 172                                 {
 173                                         // In tests, assert that the hard-coded length matches the actual one
 174                                         if $len != 0 {
 175                                                 use util::ser::LengthCalculatingWriter;
 176                                                 let mut len_calc = LengthCalculatingWriter(0);
 177                                                 $( self.$field.write(&mut len_calc).expect("No in-memory data may fail to serialize"); )*
 178                                                 assert_eq!(len_calc.0, $len);
 179                                                 assert_eq!(self.serialized_length(), $len);
 180                                         }
 181                                 }
 182                                 $( self.$field.write(w)?; )*
 183                                 Ok(())
 184                         }
 185
 186                         #[inline]
 187                         fn serialized_length(&self) -> usize {
 188                                 if $len == 0 || cfg!(any(test, feature = "fuzztarget")) {
 189                                         let mut len_calc = 0;
 190                                         $( len_calc += self.$field.serialized_length(); )*
 191                                         if $len != 0 {
 192                                                 // In tests, assert that the hard-coded length matches the actual one
 193                                                 assert_eq!(len_calc, $len);
 194                                         } else {
 195                                                 return len_calc;
 196                                         }
 197                                 }
 198                                 $len
 199                         }
 200                 }
 201
 202                 impl ::util::ser::Readable for $st {
 203                         fn read<R: ::std::io::Read>(r: &mut R) -> Result<Self, ::ln::msgs::DecodeError> {
 204                                 Ok(Self {
 205                                         $($field: ::util::ser::Readable::read(r)?),*
 206                                 })
 207                         }
 208                 }
 209         }
 210 }
 211 macro_rules! impl_writeable_len_match {
 212         ($struct: ident, $cmp: tt, ($calc_len: expr), {$({$match: pat, $length: expr}),*}, {$($field:ident),*}) => {
 213                 impl Writeable for $struct {
 214                         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 215                                 let len = match *self {
 216                                         $($match => $length,)*
 217                                 };
 218                                 w.size_hint(len);
 219                                 #[cfg(any(test, feature = "fuzztarget"))]
 220                                 {
 221                                         // In tests, assert that the hard-coded length matches the actual one
 222                                         use util::ser::LengthCalculatingWriter;
 223                                         let mut len_calc = LengthCalculatingWriter(0);
 224                                         $( self.$field.write(&mut len_calc).expect("No in-memory data may fail to serialize"); )*
 225                                         assert!(len_calc.0 $cmp len);
 226                                         assert_eq!(len_calc.0, self.serialized_length());
 227                                 }
 228                                 $( self.$field.write(w)?; )*
 229                                 Ok(())
 230                         }
 231
 232                         #[inline]
 233                         fn serialized_length(&self) -> usize {
 234                                 if $calc_len || cfg!(any(test, feature = "fuzztarget")) {
 235                                         let mut len_calc = 0;
 236                                         $( len_calc += self.$field.serialized_length(); )*
 237                                         if !$calc_len {
 238                                                 assert_eq!(len_calc, match *self {
 239                                                         $($match => $length,)*
 240                                                 });
 241                                         }
 242                                         return len_calc
 243                                 }
 244                                 match *self {
 245                                         $($match => $length,)*
 246                                 }
 247                         }
 248                 }
 249
 250                 impl ::util::ser::Readable for $struct {
 251                         fn read<R: ::std::io::Read>(r: &mut R) -> Result<Self, DecodeError> {
 252                                 Ok(Self {
 253                                         $($field: Readable::read(r)?),*
 254                                 })
 255                         }
 256                 }
 257         };
 258         ($struct: ident, $cmp: tt, {$({$match: pat, $length: expr}),*}, {$($field:ident),*}) => {
 259                 impl_writeable_len_match!($struct, $cmp, (true), { $({ $match, $length }),* }, { $($field),* });
 260         };
 261         ($struct: ident, {$({$match: pat, $length: expr}),*}, {$($field:ident),*}) => {
 262                 impl_writeable_len_match!($struct, ==, (false), { $({ $match, $length }),* }, { $($field),* });
 263         }
 264 }
 265
 266 /// Write out two bytes to indicate the version of an object.
 267 /// $this_version represents a unique version of a type. Incremented whenever the type's
 268 ///               serialization format has changed or has a new interpretation. Used by a type's
 269 ///               reader to determine how to interpret fields or if it can understand a serialized
 270 ///               object.
 271 /// $min_version_that_can_read_this is the minimum reader version which can understand this
 272 ///                                 serialized object. Previous versions will simply err with a
 273 ///                                 DecodeError::UnknownVersion.
 274 ///
 275 /// Updates to either $this_version or $min_version_that_can_read_this should be included in
 276 /// release notes.
 277 ///
 278 /// Both version fields can be specific to this type of object.
 279 macro_rules! write_ver_prefix {
 280         ($stream: expr, $this_version: expr, $min_version_that_can_read_this: expr) => {
 281                 $stream.write_all(&[$this_version; 1])?;
 282                 $stream.write_all(&[$min_version_that_can_read_this; 1])?;
 283         }
 284 }
 285
 286 /// Writes out a suffix to an object which contains potentially backwards-compatible, optional
 287 /// fields which old nodes can happily ignore.
 288 ///
 289 /// It is written out in TLV format and, as with all TLV fields, unknown even fields cause a
 290 /// DecodeError::UnknownRequiredFeature error, with unknown odd fields ignored.
 291 ///
 292 /// This is the preferred method of adding new fields that old nodes can ignore and still function
 293 /// correctly.
 294 macro_rules! write_tlv_fields {
 295         ($stream: expr, {$(($type: expr, $field: expr)),* $(,)*}, {$(($optional_type: expr, $optional_field: expr)),* $(,)*}) => {
 296                 encode_varint_length_prefixed_tlv!($stream, {$(($type, $field)),*} , {$(($optional_type, $optional_field)),*});
 297         }
 298 }
 299
 300 /// Reads a prefix added by write_ver_prefix!(), above. Takes the current version of the
 301 /// serialization logic for this object. This is compared against the
 302 /// $min_version_that_can_read_this added by write_ver_prefix!().
 303 macro_rules! read_ver_prefix {
 304         ($stream: expr, $this_version: expr) => { {
 305                 let ver: u8 = Readable::read($stream)?;
 306                 let min_ver: u8 = Readable::read($stream)?;
 307                 if min_ver > $this_version {
 308                         return Err(DecodeError::UnknownVersion);
 309                 }
 310                 ver
 311         } }
 312 }
 313
 314 /// Reads a suffix added by write_tlv_fields.
 315 macro_rules! read_tlv_fields {
 316         ($stream: expr, {$(($reqtype: expr, $reqfield: ident)),* $(,)*}, {$(($type: expr, $field: ident)),* $(,)*}) => { {
 317                 let tlv_len = ::util::ser::BigSize::read($stream)?;
 318                 let mut rd = ::util::ser::FixedLengthReader::new($stream, tlv_len.0);
 319                 decode_tlv!(&mut rd, {$(($reqtype, $reqfield)),*}, {$(($type, $field)),*});
 320                 rd.eat_remaining().map_err(|_| ::ln::msgs::DecodeError::ShortRead)?;
 321         } }
 322 }
 323
 324 // If we naively create a struct in impl_writeable_tlv_based below, we may end up returning
 325 // `Self { ,,vecfield: vecfield }` which is obviously incorrect. Instead, we have to match here to
 326 // detect at least one empty field set and skip the potentially-extra comma.
 327 macro_rules! _init_tlv_based_struct {
 328         ($($type: ident)::*, {}, {$($field: ident),*}, {$($vecfield: ident),*}) => {
 329                 Ok($($type)::* {
 330                         $($field),*,
 331                         $($vecfield: $vecfield.unwrap().0),*
 332                 })
 333         };
 334         ($($type: ident)::*, {$($reqfield: ident),*}, {}, {$($vecfield: ident),*}) => {
 335                 Ok($($type)::* {
 336                         $($reqfield: $reqfield.0.unwrap()),*,
 337                         $($vecfield: $vecfield.unwrap().0),*
 338                 })
 339         };
 340         ($($type: ident)::*, {$($reqfield: ident),*}, {$($field: ident),*}, {}) => {
 341                 Ok($($type)::* {
 342                         $($reqfield: $reqfield.0.unwrap()),*,
 343                         $($field),*
 344                 })
 345         };
 346         ($($type: ident)::*, {$($reqfield: ident),*}, {$($field: ident),*}, {$($vecfield: ident),*}) => {
 347                 Ok($($type)::* {
 348                         $($reqfield: $reqfield.0.unwrap()),*,
 349                         $($field),*,
 350                         $($vecfield: $vecfield.unwrap().0),*
 351                 })
 352         }
 353 }
 354
 355 // If we don't have any optional types below, but do have some vec types, we end up calling
 356 // `write_tlv_field!($stream, {..}, {, (vec_ty, vec_val)})`, which is obviously broken.
 357 // Instead, for write and read we match the missing values and skip the extra comma.
 358 macro_rules! _write_tlv_fields {
 359         ($stream: expr, {$(($type: expr, $field: expr)),* $(,)*}, {}, {$(($optional_type: expr, $optional_field: expr)),* $(,)*}) => {
 360                 write_tlv_fields!($stream, {$(($type, $field)),*} , {$(($optional_type, $optional_field)),*});
 361         };
 362         ($stream: expr, {$(($type: expr, $field: expr)),* $(,)*}, {$(($optional_type: expr, $optional_field: expr)),* $(,)*}, {$(($optional_type_2: expr, $optional_field_2: expr)),* $(,)*}) => {
 363                 write_tlv_fields!($stream, {$(($type, $field)),*} , {$(($optional_type, $optional_field)),*, $(($optional_type_2, $optional_field_2)),*});
 364         }
 365 }
 366 macro_rules! _get_tlv_len {
 367         ({$(($type: expr, $field: expr)),* $(,)*}, {}, {$(($optional_type: expr, $optional_field: expr)),* $(,)*}) => {
 368                 get_varint_length_prefixed_tlv_length!({$(($type, $field)),*} , {$(($optional_type, $optional_field)),*})
 369         };
 370         ({$(($type: expr, $field: expr)),* $(,)*}, {$(($optional_type: expr, $optional_field: expr)),* $(,)*}, {$(($optional_type_2: expr, $optional_field_2: expr)),* $(,)*}) => {
 371                 get_varint_length_prefixed_tlv_length!({$(($type, $field)),*} , {$(($optional_type, $optional_field)),*, $(($optional_type_2, $optional_field_2)),*})
 372         }
 373 }
 374 macro_rules! _read_tlv_fields {
 375         ($stream: expr, {$(($reqtype: expr, $reqfield: ident)),* $(,)*}, {}, {$(($type: expr, $field: ident)),* $(,)*}) => {
 376                 read_tlv_fields!($stream, {$(($reqtype, $reqfield)),*}, {$(($type, $field)),*});
 377         };
 378         ($stream: expr, {$(($reqtype: expr, $reqfield: ident)),* $(,)*}, {$(($type: expr, $field: ident)),* $(,)*}, {$(($type_2: expr, $field_2: ident)),* $(,)*}) => {
 379                 read_tlv_fields!($stream, {$(($reqtype, $reqfield)),*}, {$(($type, $field)),*, $(($type_2, $field_2)),*});
 380         }
 381 }
 382
 383 /// Implements Readable/Writeable for a struct storing it as a set of TLVs
 384 /// First block includes all the required fields including a dummy value which is used during
 385 /// deserialization but which will never be exposed to other code.
 386 /// The second block includes optional fields.
 387 /// The third block includes any Vecs which need to have their individual elements serialized.
 388 macro_rules! impl_writeable_tlv_based {
 389         ($st: ident, {$(($reqtype: expr, $reqfield: ident)),* $(,)*}, {$(($type: expr, $field: ident)),* $(,)*}, {$(($vectype: expr, $vecfield: ident)),* $(,)*}) => {
 390                 impl ::util::ser::Writeable for $st {
 391                         fn write<W: ::util::ser::Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 392                                 _write_tlv_fields!(writer, {
 393                                         $(($reqtype, self.$reqfield)),*
 394                                 }, {
 395                                         $(($type, self.$field)),*
 396                                 }, {
 397                                         $(($vectype, Some(::util::ser::VecWriteWrapper(&self.$vecfield)))),*
 398                                 });
 399                                 Ok(())
 400                         }
 401
 402                         #[inline]
 403                         fn serialized_length(&self) -> usize {
 404                                 let len = _get_tlv_len!({
 405                                         $(($reqtype, self.$reqfield)),*
 406                                 }, {
 407                                         $(($type, self.$field)),*
 408                                 }, {
 409                                         $(($vectype, Some(::util::ser::VecWriteWrapper(&self.$vecfield)))),*
 410                                 });
 411                                 use util::ser::{BigSize, LengthCalculatingWriter};
 412                                 let mut len_calc = LengthCalculatingWriter(0);
 413                                 BigSize(len as u64).write(&mut len_calc).expect("No in-memory data may fail to serialize");
 414                                 len + len_calc.0
 415                         }
 416                 }
 417
 418                 impl ::util::ser::Readable for $st {
 419                         fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, ::ln::msgs::DecodeError> {
 420                                 $(
 421                                         let mut $reqfield = ::util::ser::OptionDeserWrapper(None);
 422                                 )*
 423                                 $(
 424                                         let mut $field = None;
 425                                 )*
 426                                 $(
 427                                         let mut $vecfield = Some(::util::ser::VecReadWrapper(Vec::new()));
 428                                 )*
 429                                 _read_tlv_fields!(reader, {
 430                                         $(($reqtype, $reqfield)),*
 431                                 }, {
 432                                         $(($type, $field)),*
 433                                 }, {
 434                                         $(($vectype, $vecfield)),*
 435                                 });
 436                                 _init_tlv_based_struct!($st, {$($reqfield),*}, {$($field),*}, {$($vecfield),*})
 437                         }
 438                 }
 439         }
 440 }
 441
 442 /// Implement Readable and Writeable for an enum, with struct variants stored as TLVs and tuple
 443 /// variants stored directly.
 444 /// The format is, for example
 445 /// impl_writeable_tlv_based_enum!(EnumName,
 446 ///   (0, StructVariantA) => {(0, variant_field)}, {(1, variant_optional_field)}, {},
 447 ///   (1, StructVariantB) => {(0, variant_field_a), (1, variant_field_b)}, {}, {(2, variant_vec_field)};
 448 ///   (2, TupleVariantA), (3, TupleVariantB),
 449 /// );
 450 /// The type is written as a single byte, followed by any variant data.
 451 /// Attempts to read an unknown type byte result in DecodeError::UnknownRequiredFeature.
 452 macro_rules! impl_writeable_tlv_based_enum {
 453         ($st: ident, $(($variant_id: expr, $variant_name: ident) =>
 454                 {$(($reqtype: expr, $reqfield: ident)),* $(,)*},
 455                 {$(($type: expr, $field: ident)),* $(,)*},
 456                 {$(($vectype: expr, $vecfield: ident)),* $(,)*}
 457         ),* $(,)*;
 458         $(($tuple_variant_id: expr, $tuple_variant_name: ident)),*  $(,)*) => {
 459                 impl ::util::ser::Writeable for $st {
 460                         fn write<W: ::util::ser::Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 461                                 match self {
 462                                         $($st::$variant_name { $(ref $reqfield),* $(ref $field),*, $(ref $vecfield),* } => {
 463                                                 let id: u8 = $variant_id;
 464                                                 id.write(writer)?;
 465                                                 _write_tlv_fields!(writer, {
 466                                                         $(($reqtype, $reqfield)),*
 467                                                 }, {
 468                                                         $(($type, $field)),*
 469                                                 }, {
 470                                                         $(($vectype, Some(::util::ser::VecWriteWrapper(&$vecfield)))),*
 471                                                 });
 472                                         }),*
 473                                         $($st::$tuple_variant_name (ref field) => {
 474                                                 let id: u8 = $tuple_variant_id;
 475                                                 id.write(writer)?;
 476                                                 field.write(writer)?;
 477                                         }),*
 478                                 }
 479                                 Ok(())
 480                         }
 481                 }
 482
 483                 impl ::util::ser::Readable for $st {
 484                         fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, ::ln::msgs::DecodeError> {
 485                                 let id: u8 = ::util::ser::Readable::read(reader)?;
 486                                 match id {
 487                                         $($variant_id => {
 488                                                 // Because read_tlv_fields creates a labeled loop, we cannot call it twice
 489                                                 // in the same function body. Instead, we define a closure and call it.
 490                                                 let f = || {
 491                                                         $(
 492                                                                 let mut $reqfield = ::util::ser::OptionDeserWrapper(None);
 493                                                         )*
 494                                                         $(
 495                                                                 let mut $field = None;
 496                                                         )*
 497                                                         $(
 498                                                                 let mut $vecfield = Some(::util::ser::VecReadWrapper(Vec::new()));
 499                                                         )*
 500                                                         _read_tlv_fields!(reader, {
 501                                                                 $(($reqtype, $reqfield)),*
 502                                                         }, {
 503                                                                 $(($type, $field)),*
 504                                                         }, {
 505                                                                 $(($vectype, $vecfield)),*
 506                                                         });
 507                                                         _init_tlv_based_struct!($st::$variant_name, {$($reqfield),*}, {$($field),*}, {$($vecfield),*})
 508                                                 };
 509                                                 f()
 510                                         }),*
 511                                         $($tuple_variant_id => {
 512                                                 Ok($st::$tuple_variant_name(Readable::read(reader)?))
 513                                         }),*
 514                                         _ => {
 515                                                 Err(DecodeError::UnknownRequiredFeature)?
 516                                         },
 517                                 }
 518                         }
 519                 }
 520         }
 521 }
 522
 523 #[cfg(test)]
 524 mod tests {
 525         use prelude::*;
 526         use std::io::Cursor;
 527         use ln::msgs::DecodeError;
 528         use util::ser::{Readable, Writeable, HighZeroBytesDroppedVarInt, VecWriter};
 529         use bitcoin::secp256k1::PublicKey;
 530
 531         // The BOLT TLV test cases don't include any tests which use our "required-value" logic since
 532         // the encoding layer in the BOLTs has no such concept, though it makes our macros easier to
 533         // work with so they're baked into the decoder. Thus, we have a few additional tests below
 534         fn tlv_reader(s: &[u8]) -> Result<(u64, u32, Option<u32>), DecodeError> {
 535                 let mut s = Cursor::new(s);
 536                 let mut a: u64 = 0;
 537                 let mut b: u32 = 0;
 538                 let mut c: Option<u32> = None;
 539                 decode_tlv!(&mut s, {(2, a), (3, b)}, {(4, c)});
 540                 Ok((a, b, c))
 541         }
 542
 543         #[test]
 544         fn tlv_v_short_read() {
 545                 // We only expect a u32 for type 3 (which we are given), but the L says its 8 bytes.
 546                 if let Err(DecodeError::ShortRead) = tlv_reader(&::hex::decode(
 547                                 concat!("0100", "0208deadbeef1badbeef", "0308deadbeef")
 548                                 ).unwrap()[..]) {
 549                 } else { panic!(); }
 550         }
 551
 552         #[test]
 553         fn tlv_types_out_of_order() {
 554                 if let Err(DecodeError::InvalidValue) = tlv_reader(&::hex::decode(
 555                                 concat!("0100", "0304deadbeef", "0208deadbeef1badbeef")
 556                                 ).unwrap()[..]) {
 557                 } else { panic!(); }
 558                 // ...even if its some field we don't understand
 559                 if let Err(DecodeError::InvalidValue) = tlv_reader(&::hex::decode(
 560                                 concat!("0208deadbeef1badbeef", "0100", "0304deadbeef")
 561                                 ).unwrap()[..]) {
 562                 } else { panic!(); }
 563         }
 564
 565         #[test]
 566         fn tlv_req_type_missing_or_extra() {
 567                 // It's also bad if they included even fields we don't understand
 568                 if let Err(DecodeError::UnknownRequiredFeature) = tlv_reader(&::hex::decode(
 569                                 concat!("0100", "0208deadbeef1badbeef", "0304deadbeef", "0600")
 570                                 ).unwrap()[..]) {
 571                 } else { panic!(); }
 572                 // ... or if they're missing fields we need
 573                 if let Err(DecodeError::InvalidValue) = tlv_reader(&::hex::decode(
 574                                 concat!("0100", "0208deadbeef1badbeef")
 575                                 ).unwrap()[..]) {
 576                 } else { panic!(); }
 577                 // ... even if that field is even
 578                 if let Err(DecodeError::InvalidValue) = tlv_reader(&::hex::decode(
 579                                 concat!("0304deadbeef", "0500")
 580                                 ).unwrap()[..]) {
 581                 } else { panic!(); }
 582         }
 583
 584         #[test]
 585         fn tlv_simple_good_cases() {
 586                 assert_eq!(tlv_reader(&::hex::decode(
 587                                 concat!("0208deadbeef1badbeef", "03041bad1dea")
 588                                 ).unwrap()[..]).unwrap(),
 589                         (0xdeadbeef1badbeef, 0x1bad1dea, None));
 590                 assert_eq!(tlv_reader(&::hex::decode(
 591                                 concat!("0208deadbeef1badbeef", "03041bad1dea", "040401020304")
 592                                 ).unwrap()[..]).unwrap(),
 593                         (0xdeadbeef1badbeef, 0x1bad1dea, Some(0x01020304)));
 594         }
 595
 596         // BOLT TLV test cases
 597         fn tlv_reader_n1(s: &[u8]) -> Result<(Option<HighZeroBytesDroppedVarInt<u64>>, Option<u64>, Option<(PublicKey, u64, u64)>, Option<u16>), DecodeError> {
 598                 let mut s = Cursor::new(s);
 599                 let mut tlv1: Option<HighZeroBytesDroppedVarInt<u64>> = None;
 600                 let mut tlv2: Option<u64> = None;
 601                 let mut tlv3: Option<(PublicKey, u64, u64)> = None;
 602                 let mut tlv4: Option<u16> = None;
 603                 decode_tlv!(&mut s, {}, {(1, tlv1), (2, tlv2), (3, tlv3), (254, tlv4)});
 604                 Ok((tlv1, tlv2, tlv3, tlv4))
 605         }
 606
 607         #[test]
 608         fn bolt_tlv_bogus_stream() {
 609                 macro_rules! do_test {
 610                         ($stream: expr, $reason: ident) => {
 611                                 if let Err(DecodeError::$reason) = tlv_reader_n1(&::hex::decode($stream).unwrap()[..]) {
 612                                 } else { panic!(); }
 613                         }
 614                 }
 615
 616                 // TLVs from the BOLT test cases which should not decode as either n1 or n2
 617                 do_test!(concat!("fd01"), ShortRead);
 618                 do_test!(concat!("fd0001", "00"), InvalidValue);
 619                 do_test!(concat!("fd0101"), ShortRead);
 620                 do_test!(concat!("0f", "fd"), ShortRead);
 621                 do_test!(concat!("0f", "fd26"), ShortRead);
 622                 do_test!(concat!("0f", "fd2602"), ShortRead);
 623                 do_test!(concat!("0f", "fd0001", "00"), InvalidValue);
 624                 do_test!(concat!("0f", "fd0201", "000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"), ShortRead);
 625
 626                 do_test!(concat!("12", "00"), UnknownRequiredFeature);
 627                 do_test!(concat!("fd0102", "00"), UnknownRequiredFeature);
 628                 do_test!(concat!("fe01000002", "00"), UnknownRequiredFeature);
 629                 do_test!(concat!("ff0100000000000002", "00"), UnknownRequiredFeature);
 630         }
 631
 632         #[test]
 633         fn bolt_tlv_bogus_n1_stream() {
 634                 macro_rules! do_test {
 635                         ($stream: expr, $reason: ident) => {
 636                                 if let Err(DecodeError::$reason) = tlv_reader_n1(&::hex::decode($stream).unwrap()[..]) {
 637                                 } else { panic!(); }
 638                         }
 639                 }
 640
 641                 // TLVs from the BOLT test cases which should not decode as n1
 642                 do_test!(concat!("01", "09", "ffffffffffffffffff"), InvalidValue);
 643                 do_test!(concat!("01", "01", "00"), InvalidValue);
 644                 do_test!(concat!("01", "02", "0001"), InvalidValue);
 645                 do_test!(concat!("01", "03", "000100"), InvalidValue);
 646                 do_test!(concat!("01", "04", "00010000"), InvalidValue);
 647                 do_test!(concat!("01", "05", "0001000000"), InvalidValue);
 648                 do_test!(concat!("01", "06", "000100000000"), InvalidValue);
 649                 do_test!(concat!("01", "07", "00010000000000"), InvalidValue);
 650                 do_test!(concat!("01", "08", "0001000000000000"), InvalidValue);
 651                 do_test!(concat!("02", "07", "01010101010101"), ShortRead);
 652                 do_test!(concat!("02", "09", "010101010101010101"), InvalidValue);
 653                 do_test!(concat!("03", "21", "023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb"), ShortRead);
 654                 do_test!(concat!("03", "29", "023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb0000000000000001"), ShortRead);
 655                 do_test!(concat!("03", "30", "023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb000000000000000100000000000001"), ShortRead);
 656                 do_test!(concat!("03", "31", "043da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb00000000000000010000000000000002"), InvalidValue);
 657                 do_test!(concat!("03", "32", "023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb0000000000000001000000000000000001"), InvalidValue);
 658                 do_test!(concat!("fd00fe", "00"), ShortRead);
 659                 do_test!(concat!("fd00fe", "01", "01"), ShortRead);
 660                 do_test!(concat!("fd00fe", "03", "010101"), InvalidValue);
 661                 do_test!(concat!("00", "00"), UnknownRequiredFeature);
 662
 663                 do_test!(concat!("02", "08", "0000000000000226", "01", "01", "2a"), InvalidValue);
 664                 do_test!(concat!("02", "08", "0000000000000231", "02", "08", "0000000000000451"), InvalidValue);
 665                 do_test!(concat!("1f", "00", "0f", "01", "2a"), InvalidValue);
 666                 do_test!(concat!("1f", "00", "1f", "01", "2a"), InvalidValue);
 667
 668                 // The last BOLT test modified to not require creating a new decoder for one trivial test.
 669                 do_test!(concat!("ffffffffffffffffff", "00", "01", "00"), InvalidValue);
 670         }
 671
 672         #[test]
 673         fn bolt_tlv_valid_n1_stream() {
 674                 macro_rules! do_test {
 675                         ($stream: expr, $tlv1: expr, $tlv2: expr, $tlv3: expr, $tlv4: expr) => {
 676                                 if let Ok((tlv1, tlv2, tlv3, tlv4)) = tlv_reader_n1(&::hex::decode($stream).unwrap()[..]) {
 677                                         assert_eq!(tlv1.map(|v| v.0), $tlv1);
 678                                         assert_eq!(tlv2, $tlv2);
 679                                         assert_eq!(tlv3, $tlv3);
 680                                         assert_eq!(tlv4, $tlv4);
 681                                 } else { panic!(); }
 682                         }
 683                 }
 684
 685                 do_test!(concat!(""), None, None, None, None);
 686                 do_test!(concat!("21", "00"), None, None, None, None);
 687                 do_test!(concat!("fd0201", "00"), None, None, None, None);
 688                 do_test!(concat!("fd00fd", "00"), None, None, None, None);
 689                 do_test!(concat!("fd00ff", "00"), None, None, None, None);
 690                 do_test!(concat!("fe02000001", "00"), None, None, None, None);
 691                 do_test!(concat!("ff0200000000000001", "00"), None, None, None, None);
 692
 693                 do_test!(concat!("01", "00"), Some(0), None, None, None);
 694                 do_test!(concat!("01", "01", "01"), Some(1), None, None, None);
 695                 do_test!(concat!("01", "02", "0100"), Some(256), None, None, None);
 696                 do_test!(concat!("01", "03", "010000"), Some(65536), None, None, None);
 697                 do_test!(concat!("01", "04", "01000000"), Some(16777216), None, None, None);
 698                 do_test!(concat!("01", "05", "0100000000"), Some(4294967296), None, None, None);
 699                 do_test!(concat!("01", "06", "010000000000"), Some(1099511627776), None, None, None);
 700                 do_test!(concat!("01", "07", "01000000000000"), Some(281474976710656), None, None, None);
 701                 do_test!(concat!("01", "08", "0100000000000000"), Some(72057594037927936), None, None, None);
 702                 do_test!(concat!("02", "08", "0000000000000226"), None, Some((0 << 30) | (0 << 5) | (550 << 0)), None, None);
 703                 do_test!(concat!("03", "31", "023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb00000000000000010000000000000002"),
 704                         None, None, Some((
 705                                 PublicKey::from_slice(&::hex::decode("023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb").unwrap()[..]).unwrap(), 1, 2)),
 706                         None);
 707                 do_test!(concat!("fd00fe", "02", "0226"), None, None, None, Some(550));
 708         }
 709
 710         fn do_simple_test_tlv_write() -> Result<(), ::std::io::Error> {
 711                 let mut stream = VecWriter(Vec::new());
 712
 713                 stream.0.clear();
 714                 encode_varint_length_prefixed_tlv!(&mut stream, { (1, 1u8) }, { (42, None::<u64>) });
 715                 assert_eq!(stream.0, ::hex::decode("03010101").unwrap());
 716
 717                 stream.0.clear();
 718                 encode_varint_length_prefixed_tlv!(&mut stream, { }, { (1, Some(1u8)) });
 719                 assert_eq!(stream.0, ::hex::decode("03010101").unwrap());
 720
 721                 stream.0.clear();
 722                 encode_varint_length_prefixed_tlv!(&mut stream, { (4, 0xabcdu16) }, { (42, None::<u64>) });
 723                 assert_eq!(stream.0, ::hex::decode("040402abcd").unwrap());
 724
 725                 stream.0.clear();
 726                 encode_varint_length_prefixed_tlv!(&mut stream, { (0xff, 0xabcdu16) }, { (42, None::<u64>) });
 727                 assert_eq!(stream.0, ::hex::decode("06fd00ff02abcd").unwrap());
 728
 729                 stream.0.clear();
 730                 encode_varint_length_prefixed_tlv!(&mut stream, { (0, 1u64), (0xff, HighZeroBytesDroppedVarInt(0u64)) }, { (42, None::<u64>) });
 731                 assert_eq!(stream.0, ::hex::decode("0e00080000000000000001fd00ff00").unwrap());
 732
 733                 stream.0.clear();
 734                 encode_varint_length_prefixed_tlv!(&mut stream, { (0xff, HighZeroBytesDroppedVarInt(0u64)) }, { (0, Some(1u64)) });
 735                 assert_eq!(stream.0, ::hex::decode("0e00080000000000000001fd00ff00").unwrap());
 736
 737                 Ok(())
 738         }
 739
 740         #[test]
 741         fn simple_test_tlv_write() {
 742                 do_simple_test_tlv_write().unwrap();
 743         }
 744 }