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// Defined note types for GNU systems.
#[cfg(feature = "log")]
use log::debug;
#[cfg(feature = "alloc")]
use scroll::{IOread, IOwrite, Pread, Pwrite, SizeWith};
/// ABI information.
///
/// The descriptor consists of words:
/// * word 0: OS descriptor
/// * word 1: major version of the ABI
/// * word 2: minor version of the ABI
/// * word 3: subminor version of the ABI
pub const NT_GNU_ABI_TAG: u32 = 1;
/// Old name
pub const ELF_NOTE_ABI: u32 = NT_GNU_ABI_TAG;
// Known OSes. These values can appear in word 0 of an
// `NT_GNU_ABI_TAG` note section entry.
pub const ELF_NOTE_OS_LINUX: u32 = 0;
pub const ELF_NOTE_OS_GNU: u32 = 1;
pub const ELF_NOTE_OS_SOLARIS2: u32 = 2;
pub const ELF_NOTE_OS_FREEBSD: u32 = 3;
/// Synthetic `hwcap` information.
///
/// The descriptor begins with two words:
/// * word 0: number of entries
/// * word 1: bitmask of enabled entries
///
/// Then follow variable-length entries, one byte followed by a '\0'-terminated
/// `hwcap` name string. The byte gives the bit number to test if enabled,
/// `(1U << bit) & bitmask`.
pub const NT_GNU_HWCAP: u32 = 2;
/// Build ID bits as generated by ld --build-id.
///
/// The descriptor consists of any nonzero number of bytes.
pub const NT_GNU_BUILD_ID: u32 = 3;
/// Version note generated by GNU gold containing a version string.
pub const NT_GNU_GOLD_VERSION: u32 = 4;
/// Program property note
pub const NT_GNU_PROPERTY_TYPE_0: u32 = 5;
///Contains copy of prstatus struct.
pub const NT_PRSTATUS: u32 = 1;
///Contains copy of prpsinfo struct.
pub const NT_PRPSINFO: u32 = 3;
///Fields of siginfo_t.
pub const NT_SIGINFO: u32 = 0x5349_4749;
///Description of mapped files.
pub const NT_FILE: u32 = 0x4649_4c45;
#[derive(Clone, Copy, Debug)]
#[cfg_attr(feature = "alloc", derive(Pread, Pwrite, IOread, IOwrite, SizeWith))]
#[repr(C)]
/// Note section contents. Each entry in the note section begins with a header
/// of a fixed form.
pub struct Nhdr32 {
/// Length of the note's name (includes the terminator)
pub n_namesz: u32,
/// Length of the note's descriptor
pub n_descsz: u32,
/// Type of the note
pub n_type: u32,
}
// Declare that this is a plain type.
unsafe impl plain::Plain for Nhdr32 {}
#[derive(Clone, Copy, Debug)]
#[cfg_attr(feature = "alloc", derive(Pread, Pwrite, IOread, IOwrite, SizeWith))]
#[repr(C)]
/// Note section contents. Each entry in the note section begins with a header
/// of a fixed form.
pub struct Nhdr64 {
/// Length of the note's name (includes the terminator)
pub n_namesz: u64,
/// Length of the note's descriptor.
pub n_descsz: u64,
/// Type of the note.
pub n_type: u64,
}
// Declare that this is a plain type.
unsafe impl plain::Plain for Nhdr64 {}
if_alloc! {
use crate::error;
use crate::container;
use scroll::ctx;
use alloc::vec::Vec;
/// An iterator over ELF binary notes in a note section or segment
pub struct NoteDataIterator<'a> {
pub data: &'a [u8],
pub size: usize,
pub offset: usize,
pub ctx: (usize, container::Ctx), // (alignment, ctx)
}
impl<'a> Iterator for NoteDataIterator<'a> {
type Item = error::Result<Note<'a>>;
fn next(&mut self) -> Option<Self::Item> {
if self.offset >= self.size {
None
} else {
debug!("NoteIterator - {:#x}", self.offset);
match self.data.gread_with(&mut self.offset, self.ctx) {
Ok(res) => Some(Ok(res)),
Err(e) => Some(Err(e))
}
}
}
}
/// An iterator over ELF binary notes
pub struct NoteIterator<'a> {
pub iters: Vec<NoteDataIterator<'a>>,
pub index: usize,
}
impl<'a> Iterator for NoteIterator<'a> {
type Item = error::Result<Note<'a>>;
fn next(&mut self) -> Option<Self::Item> {
while self.index < self.iters.len() {
if let Some(note_result) = self.iters[self.index].next() {
return Some(note_result);
}
self.index += 1;
}
None
}
}
#[derive(Debug)]
struct NoteHeader {
n_namesz: usize,
n_descsz: usize,
n_type: u32,
}
impl From<Nhdr32> for NoteHeader {
fn from(header: Nhdr32) -> Self {
NoteHeader {
n_namesz: header.n_namesz as usize,
n_descsz: header.n_descsz as usize,
n_type: header.n_type,
}
}
}
impl From<Nhdr64> for NoteHeader {
fn from(header: Nhdr64) -> Self {
NoteHeader {
n_namesz: header.n_namesz as usize,
n_descsz: header.n_descsz as usize,
n_type: header.n_type as u32,
}
}
}
fn align(alignment: usize, offset: &mut usize) {
let diff = *offset % alignment;
if diff != 0 {
*offset += alignment - diff;
}
}
/// A 32/64 bit Note struct, with the name and desc pre-parsed
#[derive(Debug)]
pub struct Note<'a> {
/// The type of this note
pub n_type: u32,
/// NUL terminated string, where `namesz` includes the terminator
pub name: &'a str, // needs padding such that namesz + padding % {wordsize} == 0
/// arbitrary data of length `descsz`
pub desc: &'a [u8], // needs padding such that descsz + padding % {wordsize} == 0
}
impl<'a> Note<'a> {
pub fn type_to_str(&self) -> &'static str {
match self.n_type {
NT_GNU_ABI_TAG => "NT_GNU_ABI_TAG",
NT_GNU_HWCAP => "NT_GNU_HWCAP",
NT_GNU_BUILD_ID => "NT_GNU_BUILD_ID",
NT_GNU_GOLD_VERSION => "NT_GNU_GOLD_VERSION",
NT_GNU_PROPERTY_TYPE_0 => "NT_GNU_PROPERTY_0",
_ => "NT_UNKNOWN"
}
}
}
impl<'a> ctx::TryFromCtx<'a, (usize, container::Ctx)> for Note<'a> {
type Error = error::Error;
fn try_from_ctx(bytes: &'a [u8], (alignment, ctx): (usize, container::Ctx)) -> Result<(Self, usize), Self::Error> {
let offset = &mut 0;
let mut alignment = alignment;
if alignment < 4 {
alignment = 4;
}
let header: NoteHeader = {
match alignment {
4|8 => bytes.gread_with::<Nhdr32>(offset, ctx.le)?.into(),
_ => return Err(error::Error::Malformed(format!("Notes has unimplemented alignment requirement: {:#x}", alignment)))
}
};
debug!("{:?} - {:#x}", header, *offset);
// -1 because includes \0 terminator
let name = bytes.gread_with::<&'a str>(offset, ctx::StrCtx::Length(header.n_namesz.saturating_sub(1)))?;
if header.n_namesz > 0 {
*offset += 1;
}
align(alignment, offset);
debug!("note name {} - {:#x}", name, *offset);
let desc = bytes.gread_with::<&'a [u8]>(offset, header.n_descsz)?;
align(alignment, offset);
debug!("desc {:?} - {:#x}", desc, *offset);
Ok((Note {
name,
desc,
n_type: header.n_type,
}, *offset))
}
}
#[cfg(test)]
mod tests {
use super::*;
static NOTE_DATA: [u8; 132] = [0x04, 0x00, 0x00, 0x00, 0x10, 0x00, 0x00, 0x00,
0x01, 0x00, 0x00, 0x00, 0x47, 0x4e, 0x55, 0x00,
0x00, 0x00, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00,
0x06, 0x00, 0x00, 0x00, 0x20, 0x00, 0x00, 0x00,
0x04, 0x00, 0x00, 0x00, 0x14, 0x00, 0x00, 0x00,
0x03, 0x00, 0x00, 0x00, 0x47, 0x4e, 0x55, 0x00,
0xbc, 0xfc, 0x66, 0xcd, 0xc7, 0xd5, 0x14, 0x7b,
0x53, 0xb1, 0x10, 0x11, 0x94, 0x86, 0x8e, 0xf9,
0x4f, 0xe8, 0xdd, 0xdb, 0x04, 0x00, 0x00, 0x00,
0x30, 0x00, 0x00, 0x00, 0x05, 0x00, 0x00, 0x00,
0x47, 0x4E, 0x55, 0x00, 0x02, 0x80, 0x00, 0xC0,
0x04, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x01, 0xC0,
0x04, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x02, 0x00, 0x01, 0xC0,
0x04, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00];
static CONTEXT: (usize, container::Ctx) = (4, container::Ctx {
container: container::Container::Big,
le: ::scroll::Endian::Little,
});
fn make_note_iter(start: usize, end: usize) -> NoteDataIterator<'static> {
NoteDataIterator {
data: &NOTE_DATA,
size: end,
offset: start,
ctx: CONTEXT,
}
}
#[test]
fn iter_single_section() {
let mut notes = NoteIterator {
iters: vec![make_note_iter(0, 132)],
index: 0,
};
assert_eq!(notes.next().unwrap().unwrap().n_type, NT_GNU_ABI_TAG);
assert_eq!(notes.next().unwrap().unwrap().n_type, NT_GNU_BUILD_ID);
assert_eq!(notes.next().unwrap().unwrap().n_type, NT_GNU_PROPERTY_TYPE_0);
assert!(notes.next().is_none());
}
#[test]
fn iter_multiple_sections() {
let mut notes = NoteIterator {
iters: vec![make_note_iter(0, 32), make_note_iter(32, 68), make_note_iter(68, 132)],
index: 0,
};
assert_eq!(notes.next().unwrap().unwrap().n_type, NT_GNU_ABI_TAG);
assert_eq!(notes.next().unwrap().unwrap().n_type, NT_GNU_BUILD_ID);
assert_eq!(notes.next().unwrap().unwrap().n_type, NT_GNU_PROPERTY_TYPE_0);
assert!(notes.next().is_none());
}
#[test]
fn skip_empty_sections() {
let mut notes = NoteIterator {
iters: vec![
make_note_iter(0, 32),
make_note_iter(0, 0),
make_note_iter(32, 68),
],
index: 0,
};
assert_eq!(notes.next().unwrap().unwrap().n_type, NT_GNU_ABI_TAG);
assert_eq!(notes.next().unwrap().unwrap().n_type, NT_GNU_BUILD_ID);
assert!(notes.next().is_none());
}
#[test]
fn ignore_no_sections() {
let mut notes = NoteIterator { iters: vec![], index: 0 };
assert!(notes.next().is_none());
}
}
}