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