add LEB128 types

This commit is contained in:
Jean-Marie Mineau 2023-08-22 15:46:14 +02:00
parent 1a9030267c
commit 33e770e04a
Signed by: histausse
GPG key ID: B66AEEDA9B645AD2
5 changed files with 430 additions and 17 deletions

View file

@ -0,0 +1,318 @@
//! The implementation of serializable for LEB128 types.
use std::io::Write;
use crate::{Error, ReadSeek, Result, Serializable};
/// Signed LEB128, variable-length
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct Sleb128(i32);
/// Unsigned LEB128, variable-length
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct Uleb128(u32);
/// Unsigned LEB128 plus 1, variable-length
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct Uleb128p1(u32);
impl Sleb128 {
fn get_serialized_bytes(&self) -> Vec<u8> {
let Self(mut val) = self;
let mut bytes = vec![];
loop {
let byte = val as u8 & 0b0111_1111;
val /= 64;
if val == 0 || val == -1 {
bytes.push(byte);
return bytes;
} else {
val /= 2;
}
bytes.push(byte | 0b1000_0000);
}
}
}
impl Serializable for Sleb128 {
fn serialize(&self, output: &mut dyn Write) -> Result<()> {
output
.write_all(&self.get_serialized_bytes())
.map_err(|err| {
Error::SerializationError(format!(
"Failed to write serialize Sleb128 to output: {err}"
))
})?;
Ok(())
}
fn deserialize(input: &mut dyn ReadSeek) -> Result<Self> {
let mut shift = 0;
let mut uvalue: u64 = 0;
let mut buffer = [0u8; 1];
for _ in 0..5 {
input.read_exact(&mut buffer).map_err(|_| {
Error::InputTooSmall("Failed to read all bytes for Sleb128 from the input".into())
})?;
let byte = buffer[0];
let is_last_byte = byte & 0b1000_0000 == 0;
if is_last_byte {
uvalue += ((byte & 0b0011_1111) as u64) << shift;
let sign = ((byte & 0b0100_0000) as u64) << shift;
let value = uvalue as i64 - sign as i64;
let value: i32 = value.try_into().map_err(|err| Error::DeserializationError(
format!("Failed to parse the Sleb128 value, the encoded value is supposed to fit in 32 bits: {err}")
))?;
return Ok(Self(value));
} else {
uvalue |= ((byte & 0b0111_1111) as u64) << shift;
shift += 7;
}
}
Err(Error::DeserializationError(
"Malfored LEB128 encoding: the value cannot be longer than 5 bytes".into(),
))
}
fn size(&self) -> usize {
self.get_serialized_bytes().len()
}
}
impl Uleb128 {
fn get_serialized_bytes(&self) -> Vec<u8> {
let Self(mut val) = self;
let mut bytes = vec![];
loop {
let byte = val as u8 & 0b0111_1111;
val /= 128;
if val == 0 {
bytes.push(byte);
return bytes;
}
bytes.push(byte | 0b1000_0000);
}
}
}
impl Serializable for Uleb128 {
fn serialize(&self, output: &mut dyn Write) -> Result<()> {
output
.write_all(&self.get_serialized_bytes())
.map_err(|err| {
Error::SerializationError(format!(
"Failed to write serialize Uleb128 to output: {err}"
))
})?;
Ok(())
}
fn deserialize(input: &mut dyn ReadSeek) -> Result<Self> {
let mut shift = 0;
let mut value: u32 = 0;
let mut buffer = [0u8; 1];
for _ in 0..5 {
input.read_exact(&mut buffer).map_err(|_| {
Error::InputTooSmall("Failed to read all bytes for Uleb128 from the input".into())
})?;
let byte = buffer[0];
let is_last_byte = byte & 0b1000_0000 == 0;
value += ((byte & 0b0111_1111) as u32) << shift;
if is_last_byte {
return Ok(Self(value));
}
shift += 7;
}
Err(Error::DeserializationError(
"Malfored LEB128 encoding: the value cannot be longer than 5 bytes".into(),
))
}
fn size(&self) -> usize {
self.get_serialized_bytes().len()
}
}
impl Uleb128p1 {
pub const MINUS_ONE: Uleb128p1 = Uleb128p1(0xFFFFFFFF);
}
impl Serializable for Uleb128p1 {
fn serialize(&self, output: &mut dyn Write) -> Result<()> {
let Self(val) = self;
Uleb128(val.overflowing_add(1).0).serialize(output)
}
fn deserialize(input: &mut dyn ReadSeek) -> Result<Self> {
let Uleb128(val) = Uleb128::deserialize(input)?;
Ok(Self(val.overflowing_sub(1).0))
}
fn size(&self) -> usize {
let Self(val) = self;
Uleb128(val.overflowing_add(1).0).size()
}
}
impl From<i32> for Sleb128 {
fn from(item: i32) -> Self {
Self(item)
}
}
impl From<u32> for Uleb128 {
fn from(item: u32) -> Self {
Self(item)
}
}
impl From<u32> for Uleb128p1 {
fn from(item: u32) -> Self {
Self(item)
}
}
impl From<Sleb128> for i32 {
fn from(item: Sleb128) -> Self {
item.0
}
}
impl From<Uleb128> for u32 {
fn from(item: Uleb128) -> Self {
item.0
}
}
impl From<Uleb128p1> for u32 {
fn from(item: Uleb128p1) -> Self {
item.0
}
}
#[cfg(test)]
mod test {
use super::*;
#[test]
fn serialize_sleb128() {
assert_eq!(Sleb128(0).serialize_to_vec().unwrap(), vec![0x00u8]);
assert_eq!(Sleb128(1).serialize_to_vec().unwrap(), vec![0x01u8]);
assert_eq!(Sleb128(-1).serialize_to_vec().unwrap(), vec![0x7Fu8]);
assert_eq!(
Sleb128(-128).serialize_to_vec().unwrap(),
vec![0x80u8, 0x7F]
);
}
#[test]
fn deserialize_sleb128() {
assert_eq!(
Sleb128::deserialize_from_slice(&[0x00u8]).unwrap(),
Sleb128(0)
);
assert_eq!(
Sleb128::deserialize_from_slice(&[0x01u8]).unwrap(),
Sleb128(1)
);
assert_eq!(
Sleb128::deserialize_from_slice(&[0x7Fu8]).unwrap(),
Sleb128(-1)
);
assert_eq!(
Sleb128::deserialize_from_slice(&[0x80u8, 0x7Fu8]).unwrap(),
Sleb128(-128)
);
}
#[test]
fn size_sleb128() {
assert_eq!(Sleb128(0).size(), 1);
assert_eq!(Sleb128(1).size(), 1);
assert_eq!(Sleb128(-1).size(), 1);
assert_eq!(Sleb128(-128).size(), 2);
}
#[test]
fn serialize_uleb128() {
assert_eq!(Uleb128(0).serialize_to_vec().unwrap(), vec![0x00u8]);
assert_eq!(Uleb128(1).serialize_to_vec().unwrap(), vec![0x01u8]);
assert_eq!(Uleb128(127).serialize_to_vec().unwrap(), vec![0x7Fu8]);
assert_eq!(
Uleb128(16256).serialize_to_vec().unwrap(),
vec![0x80u8, 0x7F]
);
}
#[test]
fn deserialize_uleb128() {
assert_eq!(
Uleb128::deserialize_from_slice(&[0x00u8]).unwrap(),
Uleb128(0)
);
assert_eq!(
Uleb128::deserialize_from_slice(&[0x01u8]).unwrap(),
Uleb128(1)
);
assert_eq!(
Uleb128::deserialize_from_slice(&[0x7Fu8]).unwrap(),
Uleb128(127)
);
assert_eq!(
Uleb128::deserialize_from_slice(&[0x80u8, 0x7Fu8]).unwrap(),
Uleb128(16256)
);
}
#[test]
fn size_uleb128() {
assert_eq!(Uleb128(0).size(), 1);
assert_eq!(Uleb128(1).size(), 1);
assert_eq!(Uleb128(127).size(), 1);
assert_eq!(Uleb128(16256).size(), 2);
}
#[test]
fn serialize_uleb128p1() {
assert_eq!(
Uleb128p1::MINUS_ONE.serialize_to_vec().unwrap(),
vec![0x00u8]
);
assert_eq!(Uleb128p1(0).serialize_to_vec().unwrap(), vec![0x01u8]);
assert_eq!(Uleb128p1(126).serialize_to_vec().unwrap(), vec![0x7Fu8]);
assert_eq!(
Uleb128p1(16255).serialize_to_vec().unwrap(),
vec![0x80u8, 0x7F]
);
}
#[test]
fn deserialize_uleb128p1() {
assert_eq!(
Uleb128p1::deserialize_from_slice(&[0x00u8]).unwrap(),
Uleb128p1::MINUS_ONE
);
assert_eq!(
Uleb128p1::deserialize_from_slice(&[0x01u8]).unwrap(),
Uleb128p1(0)
);
assert_eq!(
Uleb128p1::deserialize_from_slice(&[0x7Fu8]).unwrap(),
Uleb128p1(126)
);
assert_eq!(
Uleb128p1::deserialize_from_slice(&[0x80u8, 0x7Fu8]).unwrap(),
Uleb128p1(16255)
);
}
#[test]
fn size_uleb128p1() {
assert_eq!(Uleb128p1::MINUS_ONE.size(), 1);
assert_eq!(Uleb128p1(0).size(), 1);
assert_eq!(Uleb128p1(126).size(), 1);
assert_eq!(Uleb128p1(16255).size(), 2);
}
}

View file

@ -5,10 +5,14 @@ use std::io::{Cursor, Read, Seek, SeekFrom, Write};
pub use androscalpel_serializer_derive::*;
mod leb;
pub use leb::*;
#[derive(Debug, PartialEq, Eq)]
pub enum Error {
InputTooSmall(String), // TODO: find a better name
SerializeationError(String),
SerializationError(String),
DeserializationError(String),
}
pub type Result<T> = core::result::Result<T, Error>;
@ -20,7 +24,8 @@ impl std::fmt::Display for Error {
fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
match self {
Self::InputTooSmall(msg) => write!(f, "Error: {}", msg),
Self::SerializeationError(msg) => write!(f, "Error: {}", msg),
Self::SerializationError(msg) => write!(f, "Error: {}", msg),
Self::DeserializationError(msg) => write!(f, "Error: {}", msg),
}
}
}
@ -85,15 +90,13 @@ impl<D: Serializable, U: Serializable + Eq> SerializableUntil<D, U> for Vec<D> {
let mut data = Self::new();
loop {
let pos = input.stream_position().map_err(|err| {
Error::SerializeationError(format!("Failled to get position in steam: {err}"))
Error::SerializationError(format!("Failled to get position in steam: {err}"))
})?;
match U::deserialize(input) {
Ok(val) if val == end_val => break Ok(data),
Err(err) => break Err(err),
Ok(_) => input.seek(SeekFrom::Start(pos)).map_err(|err| {
Error::SerializeationError(format!(
"Failled to get to position in steam: {err}"
))
Error::SerializationError(format!("Failled to get to position in steam: {err}"))
})?,
};
data.push(D::deserialize(input)?);
@ -108,7 +111,7 @@ impl<D: Serializable, U: Serializable + Eq> SerializableUntil<D, U> for Vec<D> {
impl Serializable for u8 {
fn serialize(&self, output: &mut dyn Write) -> Result<()> {
output.write_all(&self.to_be_bytes()).map_err(|err| {
Error::SerializeationError(format!("Failed to write serialize u8 to output: {err}"))
Error::SerializationError(format!("Failed to write serialize u8 to output: {err}"))
})?;
Ok(())
}
@ -129,7 +132,7 @@ impl Serializable for u8 {
impl Serializable for i8 {
fn serialize(&self, output: &mut dyn Write) -> Result<()> {
output.write_all(&self.to_be_bytes()).map_err(|err| {
Error::SerializeationError(format!("Failed to write serialize i8 to output: {err}"))
Error::SerializationError(format!("Failed to write serialize i8 to output: {err}"))
})?;
Ok(())
}
@ -150,7 +153,7 @@ impl Serializable for i8 {
impl Serializable for u16 {
fn serialize(&self, output: &mut dyn Write) -> Result<()> {
output.write_all(&self.to_be_bytes()).map_err(|err| {
Error::SerializeationError(format!("Failed to write serialize u16 to output: {err}"))
Error::SerializationError(format!("Failed to write serialize u16 to output: {err}"))
})?;
Ok(())
}
@ -171,7 +174,7 @@ impl Serializable for u16 {
impl Serializable for i16 {
fn serialize(&self, output: &mut dyn Write) -> Result<()> {
output.write_all(&self.to_be_bytes()).map_err(|err| {
Error::SerializeationError(format!("Failed to write serialize i16 to output: {err}"))
Error::SerializationError(format!("Failed to write serialize i16 to output: {err}"))
})?;
Ok(())
}
@ -192,7 +195,7 @@ impl Serializable for i16 {
impl Serializable for u32 {
fn serialize(&self, output: &mut dyn Write) -> Result<()> {
output.write_all(&self.to_be_bytes()).map_err(|err| {
Error::SerializeationError(format!("Failed to write serialize u32 to output: {err}"))
Error::SerializationError(format!("Failed to write serialize u32 to output: {err}"))
})?;
Ok(())
}
@ -213,7 +216,7 @@ impl Serializable for u32 {
impl Serializable for i32 {
fn serialize(&self, output: &mut dyn Write) -> Result<()> {
output.write_all(&self.to_be_bytes()).map_err(|err| {
Error::SerializeationError(format!("Failed to write serialize i32 to output: {err}"))
Error::SerializationError(format!("Failed to write serialize i32 to output: {err}"))
})?;
Ok(())
}
@ -234,7 +237,7 @@ impl Serializable for i32 {
impl Serializable for u64 {
fn serialize(&self, output: &mut dyn Write) -> Result<()> {
output.write_all(&self.to_be_bytes()).map_err(|err| {
Error::SerializeationError(format!("Failed to write serialize u64 to output: {err}"))
Error::SerializationError(format!("Failed to write serialize u64 to output: {err}"))
})?;
Ok(())
}
@ -255,7 +258,7 @@ impl Serializable for u64 {
impl Serializable for i64 {
fn serialize(&self, output: &mut dyn Write) -> Result<()> {
output.write_all(&self.to_be_bytes()).map_err(|err| {
Error::SerializeationError(format!("Failed to write serialize i64 to output: {err}"))
Error::SerializationError(format!("Failed to write serialize i64 to output: {err}"))
})?;
Ok(())
}
@ -276,7 +279,7 @@ impl Serializable for i64 {
impl Serializable for u128 {
fn serialize(&self, output: &mut dyn Write) -> Result<()> {
output.write_all(&self.to_be_bytes()).map_err(|err| {
Error::SerializeationError(format!("Failed to write serialize u128 to output: {err}"))
Error::SerializationError(format!("Failed to write serialize u128 to output: {err}"))
})?;
Ok(())
}
@ -297,7 +300,7 @@ impl Serializable for u128 {
impl Serializable for i128 {
fn serialize(&self, output: &mut dyn Write) -> Result<()> {
output.write_all(&self.to_be_bytes()).map_err(|err| {
Error::SerializeationError(format!("Failed to write serialize i128 to output: {err}"))
Error::SerializationError(format!("Failed to write serialize i128 to output: {err}"))
})?;
Ok(())
}

View file

@ -508,7 +508,7 @@ fn get_implem_deserialize(data: &Data, params: &ParamsStruct) -> TokenStream {
let prefix = <#prefix_ty as androscalpel_serializer::Serializable>::deserialize(input)?;
#(#recurse)*
Err(androscalpel_serializer::Error::SerializeationError(format!(
Err(androscalpel_serializer::Error::SerializationError(format!(
"Found prefix {:?} that did not match any variant.", prefix
)))
}

61
flake.lock generated Normal file
View file

@ -0,0 +1,61 @@
{
"nodes": {
"flake-utils": {
"inputs": {
"systems": "systems"
},
"locked": {
"lastModified": 1689068808,
"narHash": "sha256-6ixXo3wt24N/melDWjq70UuHQLxGV8jZvooRanIHXw0=",
"owner": "numtide",
"repo": "flake-utils",
"rev": "919d646de7be200f3bf08cb76ae1f09402b6f9b4",
"type": "github"
},
"original": {
"owner": "numtide",
"repo": "flake-utils",
"type": "github"
}
},
"nixpkgs": {
"locked": {
"lastModified": 1692447944,
"narHash": "sha256-fkJGNjEmTPvqBs215EQU4r9ivecV5Qge5cF/QDLVn3U=",
"owner": "NixOS",
"repo": "nixpkgs",
"rev": "d680ded26da5cf104dd2735a51e88d2d8f487b4d",
"type": "github"
},
"original": {
"owner": "NixOS",
"ref": "nixos-unstable",
"repo": "nixpkgs",
"type": "github"
}
},
"root": {
"inputs": {
"flake-utils": "flake-utils",
"nixpkgs": "nixpkgs"
}
},
"systems": {
"locked": {
"lastModified": 1681028828,
"narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
"owner": "nix-systems",
"repo": "default",
"rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
"type": "github"
},
"original": {
"owner": "nix-systems",
"repo": "default",
"type": "github"
}
}
},
"root": "root",
"version": 7
}

31
flake.nix Normal file
View file

@ -0,0 +1,31 @@
{
description = "An android bytecode manipulation library";
inputs.flake-utils.url = "github:numtide/flake-utils";
inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
outputs = { self, nixpkgs, flake-utils }:
flake-utils.lib.eachDefaultSystem (system:
let
pkgs = nixpkgs.legacyPackages.${system};
in
{
# packages = {
# androscalpel = { };
# docker = pkgs.dockerTools.buildImage {
# name = "androscalpel";
# tag = "latest";
# copyToRoot = pkgs.buildEnv {
# name = "androscalpel_root_img";
# paths = [ self.packages.${system}.androscalpel ];
# pathsToLink = [ "/bin" ];
# };
# };
# default = self.packages.${system}.androscalpel;
# };
devShells.default = pkgs.mkShell {
packages = [ pkgs.rustc pkgs.cargo ];
};
});
}