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-rw-r--r--vendor/object/src/read/elf/note.rs271
1 files changed, 271 insertions, 0 deletions
diff --git a/vendor/object/src/read/elf/note.rs b/vendor/object/src/read/elf/note.rs
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+++ b/vendor/object/src/read/elf/note.rs
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+use core::fmt::Debug;
+use core::mem;
+
+use crate::elf;
+use crate::endian::{self, U32};
+use crate::pod::Pod;
+use crate::read::util;
+use crate::read::{self, Bytes, Error, ReadError};
+
+use super::FileHeader;
+
+/// An iterator over the notes in an ELF section or segment.
+///
+/// Returned [`ProgramHeader::notes`](super::ProgramHeader::notes)
+/// and [`SectionHeader::notes`](super::SectionHeader::notes).
+#[derive(Debug)]
+pub struct NoteIterator<'data, Elf>
+where
+ Elf: FileHeader,
+{
+ endian: Elf::Endian,
+ align: usize,
+ data: Bytes<'data>,
+}
+
+impl<'data, Elf> NoteIterator<'data, Elf>
+where
+ Elf: FileHeader,
+{
+ /// An iterator over the notes in an ELF section or segment.
+ ///
+ /// `align` should be from the `p_align` field of the segment,
+ /// or the `sh_addralign` field of the section. Supported values are
+ /// either 4 or 8, but values less than 4 are treated as 4.
+ /// This matches the behaviour of binutils.
+ ///
+ /// Returns `Err` if `align` is invalid.
+ pub fn new(endian: Elf::Endian, align: Elf::Word, data: &'data [u8]) -> read::Result<Self> {
+ let align = match align.into() {
+ 0u64..=4 => 4,
+ 8 => 8,
+ _ => return Err(Error("Invalid ELF note alignment")),
+ };
+ // TODO: check data alignment?
+ Ok(NoteIterator {
+ endian,
+ align,
+ data: Bytes(data),
+ })
+ }
+
+ /// Returns the next note.
+ pub fn next(&mut self) -> read::Result<Option<Note<'data, Elf>>> {
+ let mut data = self.data;
+ if data.is_empty() {
+ return Ok(None);
+ }
+
+ let header = data
+ .read_at::<Elf::NoteHeader>(0)
+ .read_error("ELF note is too short")?;
+
+ // The name has no alignment requirement.
+ let offset = mem::size_of::<Elf::NoteHeader>();
+ let namesz = header.n_namesz(self.endian) as usize;
+ let name = data
+ .read_bytes_at(offset, namesz)
+ .read_error("Invalid ELF note namesz")?
+ .0;
+
+ // The descriptor must be aligned.
+ let offset = util::align(offset + namesz, self.align);
+ let descsz = header.n_descsz(self.endian) as usize;
+ let desc = data
+ .read_bytes_at(offset, descsz)
+ .read_error("Invalid ELF note descsz")?
+ .0;
+
+ // The next note (if any) must be aligned.
+ let offset = util::align(offset + descsz, self.align);
+ if data.skip(offset).is_err() {
+ data = Bytes(&[]);
+ }
+ self.data = data;
+
+ Ok(Some(Note { header, name, desc }))
+ }
+}
+
+/// A parsed [`NoteHeader`].
+#[derive(Debug)]
+pub struct Note<'data, Elf>
+where
+ Elf: FileHeader,
+{
+ header: &'data Elf::NoteHeader,
+ name: &'data [u8],
+ desc: &'data [u8],
+}
+
+impl<'data, Elf: FileHeader> Note<'data, Elf> {
+ /// Return the `n_type` field of the `NoteHeader`.
+ ///
+ /// The meaning of this field is determined by `name`.
+ pub fn n_type(&self, endian: Elf::Endian) -> u32 {
+ self.header.n_type(endian)
+ }
+
+ /// Return the `n_namesz` field of the `NoteHeader`.
+ pub fn n_namesz(&self, endian: Elf::Endian) -> u32 {
+ self.header.n_namesz(endian)
+ }
+
+ /// Return the `n_descsz` field of the `NoteHeader`.
+ pub fn n_descsz(&self, endian: Elf::Endian) -> u32 {
+ self.header.n_descsz(endian)
+ }
+
+ /// Return the bytes for the name field following the `NoteHeader`.
+ ///
+ /// This field is usually a string including one or more trailing null bytes
+ /// (but it is not required to be).
+ ///
+ /// The length of this field is given by `n_namesz`.
+ pub fn name_bytes(&self) -> &'data [u8] {
+ self.name
+ }
+
+ /// Return the bytes for the name field following the `NoteHeader`,
+ /// excluding all trailing null bytes.
+ pub fn name(&self) -> &'data [u8] {
+ let mut name = self.name;
+ while let [rest @ .., 0] = name {
+ name = rest;
+ }
+ name
+ }
+
+ /// Return the bytes for the desc field following the `NoteHeader`.
+ ///
+ /// The length of this field is given by `n_descsz`. The meaning
+ /// of this field is determined by `name` and `n_type`.
+ pub fn desc(&self) -> &'data [u8] {
+ self.desc
+ }
+
+ /// Return an iterator for properties if this note's type is [`elf::NT_GNU_PROPERTY_TYPE_0`].
+ pub fn gnu_properties(
+ &self,
+ endian: Elf::Endian,
+ ) -> Option<GnuPropertyIterator<'data, Elf::Endian>> {
+ if self.name() != elf::ELF_NOTE_GNU || self.n_type(endian) != elf::NT_GNU_PROPERTY_TYPE_0 {
+ return None;
+ }
+ // Use the ELF class instead of the section alignment.
+ // This matches what other parsers do.
+ let align = if Elf::is_type_64_sized() { 8 } else { 4 };
+ Some(GnuPropertyIterator {
+ endian,
+ align,
+ data: Bytes(self.desc),
+ })
+ }
+}
+
+/// A trait for generic access to [`elf::NoteHeader32`] and [`elf::NoteHeader64`].
+#[allow(missing_docs)]
+pub trait NoteHeader: Debug + Pod {
+ type Endian: endian::Endian;
+
+ fn n_namesz(&self, endian: Self::Endian) -> u32;
+ fn n_descsz(&self, endian: Self::Endian) -> u32;
+ fn n_type(&self, endian: Self::Endian) -> u32;
+}
+
+impl<Endian: endian::Endian> NoteHeader for elf::NoteHeader32<Endian> {
+ type Endian = Endian;
+
+ #[inline]
+ fn n_namesz(&self, endian: Self::Endian) -> u32 {
+ self.n_namesz.get(endian)
+ }
+
+ #[inline]
+ fn n_descsz(&self, endian: Self::Endian) -> u32 {
+ self.n_descsz.get(endian)
+ }
+
+ #[inline]
+ fn n_type(&self, endian: Self::Endian) -> u32 {
+ self.n_type.get(endian)
+ }
+}
+
+impl<Endian: endian::Endian> NoteHeader for elf::NoteHeader64<Endian> {
+ type Endian = Endian;
+
+ #[inline]
+ fn n_namesz(&self, endian: Self::Endian) -> u32 {
+ self.n_namesz.get(endian)
+ }
+
+ #[inline]
+ fn n_descsz(&self, endian: Self::Endian) -> u32 {
+ self.n_descsz.get(endian)
+ }
+
+ #[inline]
+ fn n_type(&self, endian: Self::Endian) -> u32 {
+ self.n_type.get(endian)
+ }
+}
+
+/// An iterator for the properties in a [`elf::NT_GNU_PROPERTY_TYPE_0`] note.
+///
+/// Returned by [`Note::gnu_properties`].
+#[derive(Debug)]
+pub struct GnuPropertyIterator<'data, Endian: endian::Endian> {
+ endian: Endian,
+ align: usize,
+ data: Bytes<'data>,
+}
+
+impl<'data, Endian: endian::Endian> GnuPropertyIterator<'data, Endian> {
+ /// Returns the next property.
+ pub fn next(&mut self) -> read::Result<Option<GnuProperty<'data>>> {
+ let mut data = self.data;
+ if data.is_empty() {
+ return Ok(None);
+ }
+
+ (|| -> Result<_, ()> {
+ let pr_type = data.read_at::<U32<Endian>>(0)?.get(self.endian);
+ let pr_datasz = data.read_at::<U32<Endian>>(4)?.get(self.endian) as usize;
+ let pr_data = data.read_bytes_at(8, pr_datasz)?.0;
+ data.skip(util::align(8 + pr_datasz, self.align))?;
+ self.data = data;
+ Ok(Some(GnuProperty { pr_type, pr_data }))
+ })()
+ .read_error("Invalid ELF GNU property")
+ }
+}
+
+/// A property in a [`elf::NT_GNU_PROPERTY_TYPE_0`] note.
+#[derive(Debug)]
+pub struct GnuProperty<'data> {
+ pr_type: u32,
+ pr_data: &'data [u8],
+}
+
+impl<'data> GnuProperty<'data> {
+ /// Return the property type.
+ ///
+ /// This is one of the `GNU_PROPERTY_*` constants.
+ pub fn pr_type(&self) -> u32 {
+ self.pr_type
+ }
+
+ /// Return the property data.
+ pub fn pr_data(&self) -> &'data [u8] {
+ self.pr_data
+ }
+
+ /// Parse the property data as an unsigned 32-bit integer.
+ pub fn data_u32<E: endian::Endian>(&self, endian: E) -> read::Result<u32> {
+ Bytes(self.pr_data)
+ .read_at::<U32<E>>(0)
+ .read_error("Invalid ELF GNU property data")
+ .map(|val| val.get(endian))
+ }
+}