1 //! A very simple serialization framework which is used to serialize/deserialize messages as well
2 //! as ChannelsManagers and ChannelMonitors.
4 use std::result::Result;
5 use std::io::{Read, Write};
6 use std::collections::HashMap;
11 use secp256k1::Signature;
12 use secp256k1::key::{PublicKey, SecretKey};
13 use bitcoin::blockdata::script::Script;
14 use bitcoin::blockdata::transaction::{OutPoint, Transaction};
15 use bitcoin::consensus;
16 use bitcoin::consensus::Encodable;
17 use bitcoin_hashes::sha256d::Hash as Sha256dHash;
18 use std::marker::Sized;
19 use ln::msgs::DecodeError;
20 use ln::channelmanager::{PaymentPreimage, PaymentHash};
23 use util::byte_utils::{be64_to_array, be48_to_array, be32_to_array, be16_to_array, slice_to_be16, slice_to_be32, slice_to_be48, slice_to_be64};
25 const MAX_BUF_SIZE: usize = 64 * 1024;
27 /// A trait that is similar to std::io::Write but has one extra function which can be used to size
28 /// buffers being written into.
29 /// An impl is provided for any type that also impls std::io::Write which simply ignores size
32 /// Writes the given buf out. See std::io::Write::write_all for more
33 fn write_all(&mut self, buf: &[u8]) -> Result<(), ::std::io::Error>;
34 /// Hints that data of the given size is about the be written. This may not always be called
35 /// prior to data being written and may be safely ignored.
36 fn size_hint(&mut self, size: usize);
39 impl<W: Write> Writer for W {
41 fn write_all(&mut self, buf: &[u8]) -> Result<(), ::std::io::Error> {
42 <Self as ::std::io::Write>::write_all(self, buf)
45 fn size_hint(&mut self, _size: usize) { }
48 pub(crate) struct WriterWriteAdaptor<'a, W: Writer + 'a>(pub &'a mut W);
49 impl<'a, W: Writer + 'a> Write for WriterWriteAdaptor<'a, W> {
50 fn write_all(&mut self, buf: &[u8]) -> Result<(), ::std::io::Error> {
53 fn write(&mut self, buf: &[u8]) -> Result<usize, ::std::io::Error> {
54 self.0.write_all(buf)?;
57 fn flush(&mut self) -> Result<(), ::std::io::Error> {
62 pub(crate) struct VecWriter(pub Vec<u8>);
63 impl Writer for VecWriter {
64 fn write_all(&mut self, buf: &[u8]) -> Result<(), ::std::io::Error> {
65 self.0.extend_from_slice(buf);
68 fn size_hint(&mut self, size: usize) {
69 self.0.reserve_exact(size);
73 /// Writer that only tracks the amount of data written - useful if you need to calculate the length
74 /// of some data when serialized but don't yet need the full data.
75 pub(crate) struct LengthCalculatingWriter(pub usize);
76 impl Writer for LengthCalculatingWriter {
78 fn write_all(&mut self, buf: &[u8]) -> Result<(), ::std::io::Error> {
83 fn size_hint(&mut self, _size: usize) {}
86 /// Essentially std::io::Take but a bit simpler and with a method to walk the underlying stream
87 /// forward to ensure we always consume exactly the fixed length specified.
88 pub(crate) struct FixedLengthReader<R: Read> {
93 impl<R: Read> FixedLengthReader<R> {
94 pub fn new(read: R, total_bytes: u64) -> Self {
95 Self { read, bytes_read: 0, total_bytes }
98 pub fn bytes_remain(&mut self) -> bool {
99 self.bytes_read != self.total_bytes
102 pub fn eat_remaining(&mut self) -> Result<(), DecodeError> {
103 ::std::io::copy(self, &mut ::std::io::sink()).unwrap();
104 if self.bytes_read != self.total_bytes {
105 Err(DecodeError::ShortRead)
111 impl<R: Read> Read for FixedLengthReader<R> {
112 fn read(&mut self, dest: &mut [u8]) -> Result<usize, ::std::io::Error> {
113 if self.total_bytes == self.bytes_read {
116 let read_len = cmp::min(dest.len() as u64, self.total_bytes - self.bytes_read);
117 match self.read.read(&mut dest[0..(read_len as usize)]) {
119 self.bytes_read += v as u64;
128 /// A Read which tracks whether any bytes have been read at all. This allows us to distinguish
129 /// between "EOF reached before we started" and "EOF reached mid-read".
130 pub(crate) struct ReadTrackingReader<R: Read> {
134 impl<R: Read> ReadTrackingReader<R> {
135 pub fn new(read: R) -> Self {
136 Self { read, have_read: false }
139 impl<R: Read> Read for ReadTrackingReader<R> {
140 fn read(&mut self, dest: &mut [u8]) -> Result<usize, ::std::io::Error> {
141 match self.read.read(dest) {
144 self.have_read = true;
152 /// A trait that various rust-lightning types implement allowing them to be written out to a Writer
153 pub trait Writeable {
154 /// Writes self out to the given Writer
155 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error>;
157 /// Writes self out to a Vec<u8>
158 fn encode(&self) -> Vec<u8> {
159 let mut msg = VecWriter(Vec::new());
160 self.write(&mut msg).unwrap();
164 /// Writes self out to a Vec<u8>
165 fn encode_with_len(&self) -> Vec<u8> {
166 let mut msg = VecWriter(Vec::new());
167 0u16.write(&mut msg).unwrap();
168 self.write(&mut msg).unwrap();
169 let len = msg.0.len();
170 msg.0[..2].copy_from_slice(&byte_utils::be16_to_array(len as u16 - 2));
175 /// A trait that various rust-lightning types implement allowing them to be read in from a Read
176 pub trait Readable<R>
180 /// Reads a Self in from the given Read
181 fn read(reader: &mut R) -> Result<Self, DecodeError>;
184 /// A trait that various higher-level rust-lightning types implement allowing them to be read in
185 /// from a Read given some additional set of arguments which is required to deserialize.
186 pub trait ReadableArgs<R, P>
190 /// Reads a Self in from the given Read
191 fn read(reader: &mut R, params: P) -> Result<Self, DecodeError>;
194 pub(crate) struct U48(pub u64);
195 impl Writeable for U48 {
197 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
198 writer.write_all(&be48_to_array(self.0))
201 impl<R: Read> Readable<R> for U48 {
203 fn read(reader: &mut R) -> Result<U48, DecodeError> {
204 let mut buf = [0; 6];
205 reader.read_exact(&mut buf)?;
206 Ok(U48(slice_to_be48(&buf)))
210 /// Lightning TLV uses a custom variable-length integer called BigSize. It is similar to Bitcoin's
211 /// variable-length integers except that it is serialized in big-endian instead of little-endian.
213 /// Like Bitcoin's variable-length integer, it exhibits ambiguity in that certain values can be
214 /// encoded in several different ways, which we must check for at deserialization-time. Thus, if
215 /// you're looking for an example of a variable-length integer to use for your own project, move
216 /// along, this is a rather poor design.
217 pub(crate) struct BigSize(pub u64);
218 impl Writeable for BigSize {
220 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
223 (self.0 as u8).write(writer)
226 0xFDu8.write(writer)?;
227 (self.0 as u16).write(writer)
229 0x10000...0xFFFFFFFF => {
230 0xFEu8.write(writer)?;
231 (self.0 as u32).write(writer)
234 0xFFu8.write(writer)?;
235 (self.0 as u64).write(writer)
240 impl<R: Read> Readable<R> for BigSize {
242 fn read(reader: &mut R) -> Result<BigSize, DecodeError> {
243 let n: u8 = Readable::read(reader)?;
246 let x: u64 = Readable::read(reader)?;
248 Err(DecodeError::InvalidValue)
254 let x: u32 = Readable::read(reader)?;
256 Err(DecodeError::InvalidValue)
258 Ok(BigSize(x as u64))
262 let x: u16 = Readable::read(reader)?;
264 Err(DecodeError::InvalidValue)
266 Ok(BigSize(x as u64))
269 n => Ok(BigSize(n as u64))
274 /// In TLV we occasionally send fields which only consist of, or potentially end with, a
275 /// variable-length integer which is simply truncated by skipping high zero bytes. This type
276 /// encapsulates such integers implementing Readable/Writeable for them.
277 #[cfg_attr(test, derive(PartialEq, Debug))]
278 pub(crate) struct HighZeroBytesDroppedVarInt<T>(pub T);
280 macro_rules! impl_writeable_primitive {
281 ($val_type:ty, $meth_write:ident, $len: expr, $meth_read:ident) => {
282 impl Writeable for $val_type {
284 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
285 writer.write_all(&$meth_write(*self))
288 impl Writeable for HighZeroBytesDroppedVarInt<$val_type> {
290 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
291 // Skip any full leading 0 bytes when writing (in BE):
292 writer.write_all(&$meth_write(self.0)[(self.0.leading_zeros()/8) as usize..$len])
295 impl<R: Read> Readable<R> for $val_type {
297 fn read(reader: &mut R) -> Result<$val_type, DecodeError> {
298 let mut buf = [0; $len];
299 reader.read_exact(&mut buf)?;
303 impl<R: Read> Readable<R> for HighZeroBytesDroppedVarInt<$val_type> {
305 fn read(reader: &mut R) -> Result<HighZeroBytesDroppedVarInt<$val_type>, DecodeError> {
306 // We need to accept short reads (read_len == 0) as "EOF" and handle them as simply
307 // the high bytes being dropped. To do so, we start reading into the middle of buf
308 // and then convert the appropriate number of bytes with extra high bytes out of
310 let mut buf = [0; $len*2];
311 let mut read_len = reader.read(&mut buf[$len..])?;
312 let mut total_read_len = read_len;
313 while read_len != 0 && total_read_len != $len {
314 read_len = reader.read(&mut buf[($len + total_read_len)..])?;
315 total_read_len += read_len;
317 if total_read_len == 0 || buf[$len] != 0 {
318 let first_byte = $len - ($len - total_read_len);
319 Ok(HighZeroBytesDroppedVarInt($meth_read(&buf[first_byte..first_byte + $len])))
321 // If the encoding had extra zero bytes, return a failure even though we know
322 // what they meant (as the TLV test vectors require this)
323 Err(DecodeError::InvalidValue)
330 impl_writeable_primitive!(u64, be64_to_array, 8, slice_to_be64);
331 impl_writeable_primitive!(u32, be32_to_array, 4, slice_to_be32);
332 impl_writeable_primitive!(u16, be16_to_array, 2, slice_to_be16);
334 impl Writeable for u8 {
336 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
337 writer.write_all(&[*self])
340 impl<R: Read> Readable<R> for u8 {
342 fn read(reader: &mut R) -> Result<u8, DecodeError> {
343 let mut buf = [0; 1];
344 reader.read_exact(&mut buf)?;
349 impl Writeable for bool {
351 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
352 writer.write_all(&[if *self {1} else {0}])
355 impl<R: Read> Readable<R> for bool {
357 fn read(reader: &mut R) -> Result<bool, DecodeError> {
358 let mut buf = [0; 1];
359 reader.read_exact(&mut buf)?;
360 if buf[0] != 0 && buf[0] != 1 {
361 return Err(DecodeError::InvalidValue);
368 macro_rules! impl_array {
370 impl Writeable for [u8; $size]
373 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
378 impl<R: Read> Readable<R> for [u8; $size]
381 fn read(r: &mut R) -> Result<Self, DecodeError> {
382 let mut buf = [0u8; $size];
383 r.read_exact(&mut buf)?;
390 //TODO: performance issue with [u8; size] with impl_array!()
391 impl_array!(3); // for rgb
392 impl_array!(4); // for IPv4
393 impl_array!(10); // for OnionV2
394 impl_array!(16); // for IPv6
395 impl_array!(32); // for channel id & hmac
396 impl_array!(33); // for PublicKey
397 impl_array!(64); // for Signature
398 impl_array!(1300); // for OnionPacket.hop_data
401 impl<K, V> Writeable for HashMap<K, V>
402 where K: Writeable + Eq + Hash,
406 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
407 (self.len() as u16).write(w)?;
408 for (key, value) in self.iter() {
416 impl<R, K, V> Readable<R> for HashMap<K, V>
418 K: Readable<R> + Eq + Hash,
422 fn read(r: &mut R) -> Result<Self, DecodeError> {
423 let len: u16 = Readable::read(r)?;
424 let mut ret = HashMap::with_capacity(len as usize);
426 ret.insert(K::read(r)?, V::read(r)?);
433 impl Writeable for Vec<u8> {
435 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
436 (self.len() as u16).write(w)?;
441 impl<R: Read> Readable<R> for Vec<u8> {
443 fn read(r: &mut R) -> Result<Self, DecodeError> {
444 let len: u16 = Readable::read(r)?;
445 let mut ret = Vec::with_capacity(len as usize);
446 ret.resize(len as usize, 0);
447 r.read_exact(&mut ret)?;
451 impl Writeable for Vec<Signature> {
453 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
454 (self.len() as u16).write(w)?;
455 for e in self.iter() {
462 impl<R: Read> Readable<R> for Vec<Signature> {
464 fn read(r: &mut R) -> Result<Self, DecodeError> {
465 let len: u16 = Readable::read(r)?;
466 let byte_size = (len as usize)
468 .ok_or(DecodeError::BadLengthDescriptor)?;
469 if byte_size > MAX_BUF_SIZE {
470 return Err(DecodeError::BadLengthDescriptor);
472 let mut ret = Vec::with_capacity(len as usize);
473 for _ in 0..len { ret.push(Signature::read(r)?); }
478 impl Writeable for Script {
479 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
480 (self.len() as u16).write(w)?;
481 w.write_all(self.as_bytes())
485 impl<R: Read> Readable<R> for Script {
486 fn read(r: &mut R) -> Result<Self, DecodeError> {
487 let len = <u16 as Readable<R>>::read(r)? as usize;
488 let mut buf = vec![0; len];
489 r.read_exact(&mut buf)?;
490 Ok(Script::from(buf))
494 impl Writeable for PublicKey {
495 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
496 self.serialize().write(w)
500 impl<R: Read> Readable<R> for PublicKey {
501 fn read(r: &mut R) -> Result<Self, DecodeError> {
502 let buf: [u8; 33] = Readable::read(r)?;
503 match PublicKey::from_slice(&buf) {
505 Err(_) => return Err(DecodeError::InvalidValue),
510 impl Writeable for SecretKey {
511 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
512 let mut ser = [0; 32];
513 ser.copy_from_slice(&self[..]);
518 impl<R: Read> Readable<R> for SecretKey {
519 fn read(r: &mut R) -> Result<Self, DecodeError> {
520 let buf: [u8; 32] = Readable::read(r)?;
521 match SecretKey::from_slice(&buf) {
523 Err(_) => return Err(DecodeError::InvalidValue),
528 impl Writeable for Sha256dHash {
529 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
530 w.write_all(&self[..])
534 impl<R: Read> Readable<R> for Sha256dHash {
535 fn read(r: &mut R) -> Result<Self, DecodeError> {
536 use bitcoin_hashes::Hash;
538 let buf: [u8; 32] = Readable::read(r)?;
539 Ok(Sha256dHash::from_slice(&buf[..]).unwrap())
543 impl Writeable for Signature {
544 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
545 self.serialize_compact().write(w)
549 impl<R: Read> Readable<R> for Signature {
550 fn read(r: &mut R) -> Result<Self, DecodeError> {
551 let buf: [u8; 64] = Readable::read(r)?;
552 match Signature::from_compact(&buf) {
554 Err(_) => return Err(DecodeError::InvalidValue),
559 impl Writeable for PaymentPreimage {
560 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
565 impl<R: Read> Readable<R> for PaymentPreimage {
566 fn read(r: &mut R) -> Result<Self, DecodeError> {
567 let buf: [u8; 32] = Readable::read(r)?;
568 Ok(PaymentPreimage(buf))
572 impl Writeable for PaymentHash {
573 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
578 impl<R: Read> Readable<R> for PaymentHash {
579 fn read(r: &mut R) -> Result<Self, DecodeError> {
580 let buf: [u8; 32] = Readable::read(r)?;
585 impl<T: Writeable> Writeable for Option<T> {
586 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
588 None => 0u8.write(w)?,
598 impl<R, T> Readable<R> for Option<T>
602 fn read(r: &mut R) -> Result<Self, DecodeError> {
603 match <u8 as Readable<R>>::read(r)? {
605 1 => Ok(Some(Readable::read(r)?)),
606 _ => return Err(DecodeError::InvalidValue),
611 impl Writeable for OutPoint {
612 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
619 impl<R: Read> Readable<R> for OutPoint {
620 fn read(r: &mut R) -> Result<Self, DecodeError> {
621 let txid = Readable::read(r)?;
622 let vout = Readable::read(r)?;
630 impl Writeable for Transaction {
631 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
632 match self.consensus_encode(WriterWriteAdaptor(writer)) {
634 Err(consensus::encode::Error::Io(e)) => Err(e),
635 Err(_) => panic!("We shouldn't get a consensus::encode::Error unless our Write generated an std::io::Error"),
640 impl<R: Read> Readable<R> for Transaction {
641 fn read(r: &mut R) -> Result<Self, DecodeError> {
642 match consensus::encode::Decodable::consensus_decode(r) {
644 Err(consensus::encode::Error::Io(ref e)) if e.kind() == ::std::io::ErrorKind::UnexpectedEof => Err(DecodeError::ShortRead),
645 Err(consensus::encode::Error::Io(e)) => Err(DecodeError::Io(e)),
646 Err(_) => Err(DecodeError::InvalidValue),
651 impl<R: Read, T: Readable<R>> Readable<R> for Mutex<T> {
652 fn read(r: &mut R) -> Result<Self, DecodeError> {
653 let t: T = Readable::read(r)?;
657 impl<T: Writeable> Writeable for Mutex<T> {
658 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
659 self.lock().unwrap().write(w)
663 impl<R: Read, A: Readable<R>, B: Readable<R>> Readable<R> for (A, B) {
664 fn read(r: &mut R) -> Result<Self, DecodeError> {
665 let a: A = Readable::read(r)?;
666 let b: B = Readable::read(r)?;
670 impl<A: Writeable, B: Writeable> Writeable for (A, B) {
671 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {