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extract parse fat arch code
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@flier
flier committed Jun 18, 2022
1 parent 32501c8 commit 9e8869d
Showing 1 changed file with 82 additions and 59 deletions.
141 changes: 82 additions & 59 deletions src/loader.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -9,18 +9,6 @@ use crate::commands::{LoadCommand, ReadStringExt};
use crate::consts::*;
use crate::errors::{Error::*, Result};

/// The architecture of mach header
///
pub trait MachArch {
/// parse mach header
fn parse_mach_header<T: BufRead, O: ByteOrder>(magic: u32, buf: &mut T) -> Result<MachHeader>;
}

/// The 32-bit mach header
pub enum Arch32 {}
/// The 64-bit mach header
pub enum Arch64 {}

#[cfg(windows)]
type uid_t = libc::uint32_t;
#[cfg(windows)]
Expand All @@ -34,7 +22,19 @@ type gid_t = libc::gid_t;
#[cfg(not(windows))]
type mode_t = libc::mode_t;

impl MachArch for Arch32 {
/// The 32-bit mach/fat header
pub enum Arch32 {}
/// The 64-bit mach/fat header
pub enum Arch64 {}

/// The architecture of mach header
///
pub trait MachHeaderParser {
/// parse mach header
fn parse_mach_header<T: BufRead, O: ByteOrder>(magic: u32, buf: &mut T) -> Result<MachHeader>;
}

impl MachHeaderParser for Arch32 {
fn parse_mach_header<T: BufRead, O: ByteOrder>(magic: u32, buf: &mut T) -> Result<MachHeader> {
let header = MachHeader {
magic,
Expand All @@ -50,7 +50,7 @@ impl MachArch for Arch32 {
}
}

impl MachArch for Arch64 {
impl MachHeaderParser for Arch64 {
fn parse_mach_header<T: BufRead, O: ByteOrder>(magic: u32, buf: &mut T) -> Result<MachHeader> {
let header = MachHeader {
magic,
Expand Down Expand Up @@ -124,6 +124,41 @@ pub struct FatHeader {
pub archs: Vec<FatArch>,
}

/// The architecture of mach header
///
pub trait FatArchParser {
/// parse fat arch
fn parse_fat_arch<T: BufRead, O: ByteOrder>(buf: &mut T) -> Result<FatArch>;
}

impl FatArchParser for Arch32 {
fn parse_fat_arch<T: BufRead, O: ByteOrder>(buf: &mut T) -> Result<FatArch> {
Ok(FatArch {
cputype: buf.read_u32::<O>()? as cpu_type_t,
cpusubtype: buf.read_u32::<O>()? as cpu_subtype_t,
offset: buf.read_u32::<O>()? as u64,
size: buf.read_u32::<O>()? as u64,
align: buf.read_u32::<O>()?,
})
}
}

impl FatArchParser for Arch64 {
fn parse_fat_arch<T: BufRead, O: ByteOrder>(buf: &mut T) -> Result<FatArch> {
Ok(FatArch {
cputype: buf.read_u32::<O>()? as cpu_type_t,
cpusubtype: buf.read_u32::<O>()? as cpu_subtype_t,
offset: buf.read_u64::<O>()?,
size: buf.read_u64::<O>()?,
align: {
let align = buf.read_u32::<O>()?;
let _reserved = buf.read_u32::<O>()?;
align
},
})
}
}

/// For each architecture in the file, specified by a pair of cputype and cpusubtype,
/// the `FatArch` describes the file offset, file size and alignment
/// in the file of the architecture specific member.
Expand Down Expand Up @@ -270,7 +305,8 @@ impl OFile {
MH_CIGAM => Self::parse_mach_file::<Arch32, BigEndian, T>(magic, buf),
MH_MAGIC_64 => Self::parse_mach_file::<Arch64, LittleEndian, T>(magic, buf),
MH_CIGAM_64 => Self::parse_mach_file::<Arch64, BigEndian, T>(magic, buf),
FAT_MAGIC | FAT_MAGIC64 | FAT_CIGAM | FAT_CIGAM64 => Self::parse_fat_file::<BigEndian, T>(magic, buf),
FAT_MAGIC | FAT_CIGAM => Self::parse_fat_file::<Arch32, BigEndian, T>(magic, buf),
FAT_MAGIC64 | FAT_CIGAM64 => Self::parse_fat_file::<Arch64, BigEndian, T>(magic, buf),
_ => {
let mut ar_magic = [0; 8];

Expand All @@ -291,10 +327,13 @@ impl OFile {
}
}

fn parse_mach_file<A: MachArch, O: ByteOrder, T: AsRef<[u8]>>(magic: u32, buf: &mut Cursor<T>) -> Result<OFile> {
fn parse_mach_file<P: MachHeaderParser, O: ByteOrder, T: AsRef<[u8]>>(
magic: u32,
buf: &mut Cursor<T>,
) -> Result<OFile> {
debug!("0x{:08x}\tparsing macho-o file header", buf.position());

let header = A::parse_mach_header::<Cursor<T>, O>(magic, buf)?;
let header = P::parse_mach_header::<_, O>(magic, buf)?;

debug!("parsed mach-o file header: {:?}", header);

Expand All @@ -311,7 +350,10 @@ impl OFile {
Ok(OFile::MachFile { header, commands })
}

fn parse_fat_file<O: ByteOrder, T: AsRef<[u8]>>(magic: u32, buf: &mut Cursor<T>) -> Result<OFile> {
fn parse_fat_file<P: FatArchParser, O: ByteOrder, T: AsRef<[u8]>>(
magic: u32,
buf: &mut Cursor<T>,
) -> Result<OFile> {
debug!("0x{:08x}\tparsing fat file header", buf.position());

let nfat_arch = buf.read_u32::<O>()?;
Expand All @@ -323,55 +365,36 @@ impl OFile {
magic
);

let mut archs = Vec::new();

for i in 0..nfat_arch {
let arch = if matches!(magic, FAT_MAGIC64 | FAT_CIGAM64) {
FatArch {
cputype: buf.read_u32::<O>()? as cpu_type_t,
cpusubtype: buf.read_u32::<O>()? as cpu_subtype_t,
offset: buf.read_u64::<O>()?,
size: buf.read_u64::<O>()?,
align: {
let align = buf.read_u32::<O>()?;
let _reserved = buf.read_u32::<O>()?;
align
},
}
} else {
FatArch {
cputype: buf.read_u32::<O>()? as cpu_type_t,
cpusubtype: buf.read_u32::<O>()? as cpu_subtype_t,
offset: buf.read_u32::<O>()? as u64,
size: buf.read_u32::<O>()? as u64,
align: buf.read_u32::<O>()?,
}
};
let archs = (0..nfat_arch)
.map(|i| {
let arch = P::parse_fat_arch::<_, O>(buf)?;

debug!("0x{:08}\tfat header arch#{}, arch={:?}", buf.position(), i, arch);
debug!("0x{:08}\tfat header arch#{}, arch={:?}", buf.position(), i, arch);

archs.push(arch);
}
Ok(arch)
})
.collect::<Result<Vec<_>>>()?;

let start = buf.position();
let payload = buf.get_ref().as_ref();
let mut files = Vec::new();

for arch in archs {
if u64::from(arch.offset) < start {
return Err(BufferOverflow(arch.offset as usize));
}

let content = payload.checked_slice(arch.offset as usize, arch.size as usize)?;
let files = archs
.into_iter()
.map(|arch| {
if u64::from(arch.offset) < start {
Err(BufferOverflow(arch.offset as usize))
} else {
let content = payload.checked_slice(arch.offset as usize, arch.size as usize)?;

debug!("0x{:08}\tparsing mach-o file, arch={:?}", arch.offset, arch);
debug!("0x{:08}\tparsing mach-o file, arch={:?}", arch.offset, arch);

let mut cur = Cursor::new(content);
let mut cur = Cursor::new(content);

let file = OFile::parse(&mut cur)?;
let file = OFile::parse(&mut cur)?;

files.push((arch, file));
}
Ok((arch, file))
}
})
.collect::<Result<Vec<_>>>()?;

Ok(OFile::FatFile { magic, files })
}
Expand Down Expand Up @@ -470,7 +493,7 @@ pub mod tests {
use byteorder::{BigEndian, LittleEndian};

use super::super::*;
use super::{Arch64, MachArch};
use super::{Arch64, MachHeaderParser};

/**
Mach header
Expand Down

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