use std::collections::HashMap;
use std::hash::Hash;
use std::sync::Mutex;
+use std::cmp;
use secp256k1::Signature;
use secp256k1::key::{PublicKey, SecretKey};
}
}
+/// Writer that only tracks the amount of data written - useful if you need to calculate the length
+/// of some data when serialized but don't yet need the full data.
+pub(crate) struct LengthCalculatingWriter(pub usize);
+impl Writer for LengthCalculatingWriter {
+ #[inline]
+ fn write_all(&mut self, buf: &[u8]) -> Result<(), ::std::io::Error> {
+ self.0 += buf.len();
+ Ok(())
+ }
+ #[inline]
+ fn size_hint(&mut self, _size: usize) {}
+}
+
+/// Essentially std::io::Take but a bit simpler and with a method to walk the underlying stream
+/// forward to ensure we always consume exactly the fixed length specified.
+pub(crate) struct FixedLengthReader<R: Read> {
+ read: R,
+ bytes_read: u64,
+ total_bytes: u64,
+}
+impl<R: Read> FixedLengthReader<R> {
+ pub fn new(read: R, total_bytes: u64) -> Self {
+ Self { read, bytes_read: 0, total_bytes }
+ }
+
+ pub fn bytes_remain(&mut self) -> bool {
+ self.bytes_read != self.total_bytes
+ }
+
+ pub fn eat_remaining(&mut self) -> Result<(), DecodeError> {
+ ::std::io::copy(self, &mut ::std::io::sink()).unwrap();
+ if self.bytes_read != self.total_bytes {
+ Err(DecodeError::ShortRead)
+ } else {
+ Ok(())
+ }
+ }
+}
+impl<R: Read> Read for FixedLengthReader<R> {
+ fn read(&mut self, dest: &mut [u8]) -> Result<usize, ::std::io::Error> {
+ if self.total_bytes == self.bytes_read {
+ Ok(0)
+ } else {
+ let read_len = cmp::min(dest.len() as u64, self.total_bytes - self.bytes_read);
+ match self.read.read(&mut dest[0..(read_len as usize)]) {
+ Ok(v) => {
+ self.bytes_read += v as u64;
+ Ok(v)
+ },
+ Err(e) => Err(e),
+ }
+ }
+ }
+}
+
+/// A Read which tracks whether any bytes have been read at all. This allows us to distinguish
+/// between "EOF reached before we started" and "EOF reached mid-read".
+pub(crate) struct ReadTrackingReader<R: Read> {
+ read: R,
+ pub have_read: bool,
+}
+impl<R: Read> ReadTrackingReader<R> {
+ pub fn new(read: R) -> Self {
+ Self { read, have_read: false }
+ }
+}
+impl<R: Read> Read for ReadTrackingReader<R> {
+ fn read(&mut self, dest: &mut [u8]) -> Result<usize, ::std::io::Error> {
+ match self.read.read(dest) {
+ Ok(0) => Ok(0),
+ Ok(len) => {
+ self.have_read = true;
+ Ok(len)
+ },
+ Err(e) => Err(e),
+ }
+ }
+}
+
/// A trait that various rust-lightning types implement allowing them to be written out to a Writer
pub trait Writeable {
/// Writes self out to the given Writer
}
}
+/// Lightning TLV uses a custom variable-length integer called BigSize. It is similar to Bitcoin's
+/// variable-length integers except that it is serialized in big-endian instead of little-endian.
+///
+/// Like Bitcoin's variable-length integer, it exhibits ambiguity in that certain values can be
+/// encoded in several different ways, which we must check for at deserialization-time. Thus, if
+/// you're looking for an example of a variable-length integer to use for your own project, move
+/// along, this is a rather poor design.
+pub(crate) struct BigSize(pub u64);
+impl Writeable for BigSize {
+ #[inline]
+ fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
+ match self.0 {
+ 0...0xFC => {
+ (self.0 as u8).write(writer)
+ },
+ 0xFD...0xFFFF => {
+ 0xFDu8.write(writer)?;
+ (self.0 as u16).write(writer)
+ },
+ 0x10000...0xFFFFFFFF => {
+ 0xFEu8.write(writer)?;
+ (self.0 as u32).write(writer)
+ },
+ _ => {
+ 0xFFu8.write(writer)?;
+ (self.0 as u64).write(writer)
+ },
+ }
+ }
+}
+impl<R: Read> Readable<R> for BigSize {
+ #[inline]
+ fn read(reader: &mut R) -> Result<BigSize, DecodeError> {
+ let n: u8 = Readable::read(reader)?;
+ match n {
+ 0xFF => {
+ let x: u64 = Readable::read(reader)?;
+ if x < 0x100000000 {
+ Err(DecodeError::InvalidValue)
+ } else {
+ Ok(BigSize(x))
+ }
+ }
+ 0xFE => {
+ let x: u32 = Readable::read(reader)?;
+ if x < 0x10000 {
+ Err(DecodeError::InvalidValue)
+ } else {
+ Ok(BigSize(x as u64))
+ }
+ }
+ 0xFD => {
+ let x: u16 = Readable::read(reader)?;
+ if x < 0xFD {
+ Err(DecodeError::InvalidValue)
+ } else {
+ Ok(BigSize(x as u64))
+ }
+ }
+ n => Ok(BigSize(n as u64))
+ }
+ }
+}
+
+/// In TLV we occasionally send fields which only consist of, or potentially end with, a
+/// variable-length integer which is simply truncated by skipping high zero bytes. This type
+/// encapsulates such integers implementing Readable/Writeable for them.
+#[cfg_attr(test, derive(PartialEq, Debug))]
+pub(crate) struct HighZeroBytesDroppedVarInt<T>(pub T);
+
macro_rules! impl_writeable_primitive {
($val_type:ty, $meth_write:ident, $len: expr, $meth_read:ident) => {
impl Writeable for $val_type {
writer.write_all(&$meth_write(*self))
}
}
+ impl Writeable for HighZeroBytesDroppedVarInt<$val_type> {
+ #[inline]
+ fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
+ // Skip any full leading 0 bytes when writing (in BE):
+ writer.write_all(&$meth_write(self.0)[(self.0.leading_zeros()/8) as usize..$len])
+ }
+ }
impl<R: Read> Readable<R> for $val_type {
#[inline]
fn read(reader: &mut R) -> Result<$val_type, DecodeError> {
Ok($meth_read(&buf))
}
}
+ impl<R: Read> Readable<R> for HighZeroBytesDroppedVarInt<$val_type> {
+ #[inline]
+ fn read(reader: &mut R) -> Result<HighZeroBytesDroppedVarInt<$val_type>, DecodeError> {
+ // We need to accept short reads (read_len == 0) as "EOF" and handle them as simply
+ // the high bytes being dropped. To do so, we start reading into the middle of buf
+ // and then convert the appropriate number of bytes with extra high bytes out of
+ // buf.
+ let mut buf = [0; $len*2];
+ let mut read_len = reader.read(&mut buf[$len..])?;
+ let mut total_read_len = read_len;
+ while read_len != 0 && total_read_len != $len {
+ read_len = reader.read(&mut buf[($len + total_read_len)..])?;
+ total_read_len += read_len;
+ }
+ if total_read_len == 0 || buf[$len] != 0 {
+ let first_byte = $len - ($len - total_read_len);
+ Ok(HighZeroBytesDroppedVarInt($meth_read(&buf[first_byte..first_byte + $len])))
+ } else {
+ // If the encoding had extra zero bytes, return a failure even though we know
+ // what they meant (as the TLV test vectors require this)
+ Err(DecodeError::InvalidValue)
+ }
+ }
+ }
}
}
projects / rust-lightning / commitdiff