Initial vendor packages

Signed-off-by: Valentin Popov <valentin@popov.link>

1 files changed, 333 insertions, 0 deletions

diff --git a/vendor/object/src/read/pe/export.rs b/vendor/object/src/read/pe/export.rs
new file mode 100644
index 0000000..1aba844
--- /dev/null
+++ b/vendor/object/src/read/pe/export.rs
@@ -0,0 +1,333 @@
+use alloc::vec::Vec;
+use core::fmt::Debug;
+
+use crate::read::{ByteString, Bytes, Error, ReadError, ReadRef, Result};
+use crate::{pe, LittleEndian as LE, U16Bytes, U32Bytes};
+
+/// Where an export is pointing to.
+#[derive(Clone, Copy)]
+pub enum ExportTarget<'data> {
+    /// The address of the export, relative to the image base.
+    Address(u32),
+    /// Forwarded to an export ordinal in another DLL.
+    ///
+    /// This gives the name of the DLL, and the ordinal.
+    ForwardByOrdinal(&'data [u8], u32),
+    /// Forwarded to an export name in another DLL.
+    ///
+    /// This gives the name of the DLL, and the export name.
+    ForwardByName(&'data [u8], &'data [u8]),
+}
+
+impl<'data> ExportTarget<'data> {
+    /// Returns true if the target is an address.
+    pub fn is_address(&self) -> bool {
+        match self {
+            ExportTarget::Address(_) => true,
+            _ => false,
+        }
+    }
+
+    /// Returns true if the export is forwarded to another DLL.
+    pub fn is_forward(&self) -> bool {
+        !self.is_address()
+    }
+}
+
+/// An export from a PE file.
+///
+/// There are multiple kinds of PE exports (with or without a name, and local or forwarded).
+#[derive(Clone, Copy)]
+pub struct Export<'data> {
+    /// The ordinal of the export.
+    ///
+    /// These are sequential, starting at a base specified in the DLL.
+    pub ordinal: u32,
+    /// The name of the export, if known.
+    pub name: Option<&'data [u8]>,
+    /// The target of this export.
+    pub target: ExportTarget<'data>,
+}
+
+impl<'a> Debug for Export<'a> {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::result::Result<(), core::fmt::Error> {
+        f.debug_struct("Export")
+            .field("ordinal", &self.ordinal)
+            .field("name", &self.name.map(ByteString))
+            .field("target", &self.target)
+            .finish()
+    }
+}
+
+impl<'a> Debug for ExportTarget<'a> {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::result::Result<(), core::fmt::Error> {
+        match self {
+            ExportTarget::Address(address) => write!(f, "Address({:#x})", address),
+            ExportTarget::ForwardByOrdinal(library, ordinal) => write!(
+                f,
+                "ForwardByOrdinal({:?}.#{})",
+                ByteString(library),
+                ordinal
+            ),
+            ExportTarget::ForwardByName(library, name) => write!(
+                f,
+                "ForwardByName({:?}.{:?})",
+                ByteString(library),
+                ByteString(name)
+            ),
+        }
+    }
+}
+
+/// A partially parsed PE export table.
+///
+/// Returned by [`DataDirectories::export_table`](super::DataDirectories::export_table).
+#[derive(Debug, Clone)]
+pub struct ExportTable<'data> {
+    data: Bytes<'data>,
+    virtual_address: u32,
+    directory: &'data pe::ImageExportDirectory,
+    addresses: &'data [U32Bytes<LE>],
+    names: &'data [U32Bytes<LE>],
+    name_ordinals: &'data [U16Bytes<LE>],
+}
+
+impl<'data> ExportTable<'data> {
+    /// Parse the export table given its section data and address.
+    pub fn parse(data: &'data [u8], virtual_address: u32) -> Result<Self> {
+        let directory = Self::parse_directory(data)?;
+        let data = Bytes(data);
+
+        let mut addresses = &[][..];
+        let address_of_functions = directory.address_of_functions.get(LE);
+        if address_of_functions != 0 {
+            addresses = data
+                .read_slice_at::<U32Bytes<_>>(
+                    address_of_functions.wrapping_sub(virtual_address) as usize,
+                    directory.number_of_functions.get(LE) as usize,
+                )
+                .read_error("Invalid PE export address table")?;
+        }
+
+        let mut names = &[][..];
+        let mut name_ordinals = &[][..];
+        let address_of_names = directory.address_of_names.get(LE);
+        let address_of_name_ordinals = directory.address_of_name_ordinals.get(LE);
+        if address_of_names != 0 {
+            if address_of_name_ordinals == 0 {
+                return Err(Error("Missing PE export ordinal table"));
+            }
+
+            let number = directory.number_of_names.get(LE) as usize;
+            names = data
+                .read_slice_at::<U32Bytes<_>>(
+                    address_of_names.wrapping_sub(virtual_address) as usize,
+                    number,
+                )
+                .read_error("Invalid PE export name pointer table")?;
+            name_ordinals = data
+                .read_slice_at::<U16Bytes<_>>(
+                    address_of_name_ordinals.wrapping_sub(virtual_address) as usize,
+                    number,
+                )
+                .read_error("Invalid PE export ordinal table")?;
+        }
+
+        Ok(ExportTable {
+            data,
+            virtual_address,
+            directory,
+            addresses,
+            names,
+            name_ordinals,
+        })
+    }
+
+    /// Parse the export directory given its section data.
+    pub fn parse_directory(data: &'data [u8]) -> Result<&'data pe::ImageExportDirectory> {
+        data.read_at::<pe::ImageExportDirectory>(0)
+            .read_error("Invalid PE export dir size")
+    }
+
+    /// Returns the header of the export table.
+    pub fn directory(&self) -> &'data pe::ImageExportDirectory {
+        self.directory
+    }
+
+    /// Returns the base value of ordinals.
+    ///
+    /// Adding this to an address index will give an ordinal.
+    pub fn ordinal_base(&self) -> u32 {
+        self.directory.base.get(LE)
+    }
+
+    /// Returns the unparsed address table.
+    ///
+    /// An address table entry may be a local address, or the address of a forwarded export entry.
+    /// See [`Self::is_forward`] and [`Self::target_from_address`].
+    pub fn addresses(&self) -> &'data [U32Bytes<LE>] {
+        self.addresses
+    }
+
+    /// Returns the unparsed name pointer table.
+    ///
+    /// A name pointer table entry can be used with [`Self::name_from_pointer`].
+    pub fn name_pointers(&self) -> &'data [U32Bytes<LE>] {
+        self.names
+    }
+
+    /// Returns the unparsed ordinal table.
+    ///
+    /// An ordinal table entry is a 0-based index into the address table.
+    /// See [`Self::address_by_index`] and [`Self::target_by_index`].
+    pub fn name_ordinals(&self) -> &'data [U16Bytes<LE>] {
+        self.name_ordinals
+    }
+
+    /// Returns an iterator for the entries in the name pointer table and ordinal table.
+    ///
+    /// A name pointer table entry can be used with [`Self::name_from_pointer`].
+    ///
+    /// An ordinal table entry is a 0-based index into the address table.
+    /// See [`Self::address_by_index`] and [`Self::target_by_index`].
+    pub fn name_iter(&self) -> impl Iterator<Item = (u32, u16)> + 'data {
+        self.names
+            .iter()
+            .map(|x| x.get(LE))
+            .zip(self.name_ordinals.iter().map(|x| x.get(LE)))
+    }
+
+    /// Returns the export address table entry at the given address index.
+    ///
+    /// This may be a local address, or the address of a forwarded export entry.
+    /// See [`Self::is_forward`] and [`Self::target_from_address`].
+    ///
+    /// `index` is a 0-based index into the export address table.
+    pub fn address_by_index(&self, index: u32) -> Result<u32> {
+        Ok(self
+            .addresses
+            .get(index as usize)
+            .read_error("Invalid PE export address index")?
+            .get(LE))
+    }
+
+    /// Returns the export address table entry at the given ordinal.
+    ///
+    /// This may be a local address, or the address of a forwarded export entry.
+    /// See [`Self::is_forward`] and [`Self::target_from_address`].
+    pub fn address_by_ordinal(&self, ordinal: u32) -> Result<u32> {
+        self.address_by_index(ordinal.wrapping_sub(self.ordinal_base()))
+    }
+
+    /// Returns the target of the export at the given address index.
+    ///
+    /// `index` is a 0-based index into the export address table.
+    pub fn target_by_index(&self, index: u32) -> Result<ExportTarget<'data>> {
+        self.target_from_address(self.address_by_index(index)?)
+    }
+
+    /// Returns the target of the export at the given ordinal.
+    pub fn target_by_ordinal(&self, ordinal: u32) -> Result<ExportTarget<'data>> {
+        self.target_from_address(self.address_by_ordinal(ordinal)?)
+    }
+
+    /// Convert an export address table entry into a target.
+    pub fn target_from_address(&self, address: u32) -> Result<ExportTarget<'data>> {
+        Ok(if let Some(forward) = self.forward_string(address)? {
+            let i = forward
+                .iter()
+                .position(|x| *x == b'.')
+                .read_error("Missing PE forwarded export separator")?;
+            let library = &forward[..i];
+            match &forward[i + 1..] {
+                [b'#', digits @ ..] => {
+                    let ordinal =
+                        parse_ordinal(digits).read_error("Invalid PE forwarded export ordinal")?;
+                    ExportTarget::ForwardByOrdinal(library, ordinal)
+                }
+                [] => {
+                    return Err(Error("Missing PE forwarded export name"));
+                }
+                name => ExportTarget::ForwardByName(library, name),
+            }
+        } else {
+            ExportTarget::Address(address)
+        })
+    }
+
+    fn forward_offset(&self, address: u32) -> Option<usize> {
+        let offset = address.wrapping_sub(self.virtual_address) as usize;
+        if offset < self.data.len() {
+            Some(offset)
+        } else {
+            None
+        }
+    }
+
+    /// Return true if the export address table entry is a forward.
+    pub fn is_forward(&self, address: u32) -> bool {
+        self.forward_offset(address).is_some()
+    }
+
+    /// Return the forward string if the export address table entry is a forward.
+    pub fn forward_string(&self, address: u32) -> Result<Option<&'data [u8]>> {
+        if let Some(offset) = self.forward_offset(address) {
+            self.data
+                .read_string_at(offset)
+                .read_error("Invalid PE forwarded export address")
+                .map(Some)
+        } else {
+            Ok(None)
+        }
+    }
+
+    /// Convert an export name pointer table entry into a name.
+    pub fn name_from_pointer(&self, name_pointer: u32) -> Result<&'data [u8]> {
+        let offset = name_pointer.wrapping_sub(self.virtual_address);
+        self.data
+            .read_string_at(offset as usize)
+            .read_error("Invalid PE export name pointer")
+    }
+
+    /// Returns the parsed exports in this table.
+    pub fn exports(&self) -> Result<Vec<Export<'data>>> {
+        // First, let's list all exports.
+        let mut exports = Vec::new();
+        let ordinal_base = self.ordinal_base();
+        for (i, address) in self.addresses.iter().enumerate() {
+            // Convert from an array index to an ordinal.
+            let ordinal = ordinal_base.wrapping_add(i as u32);
+            let target = self.target_from_address(address.get(LE))?;
+            exports.push(Export {
+                ordinal,
+                target,
+                // Might be populated later.
+                name: None,
+            });
+        }
+
+        // Now, check whether some (or all) of them have an associated name.
+        // `ordinal_index` is a 0-based index into `addresses`.
+        for (name_pointer, ordinal_index) in self.name_iter() {
+            let name = self.name_from_pointer(name_pointer)?;
+            exports
+                .get_mut(ordinal_index as usize)
+                .read_error("Invalid PE export ordinal")?
+                .name = Some(name);
+        }
+
+        Ok(exports)
+    }
+}
+
+fn parse_ordinal(digits: &[u8]) -> Option<u32> {
+    if digits.is_empty() {
+        return None;
+    }
+    let mut result: u32 = 0;
+    for &c in digits {
+        let x = (c as char).to_digit(10)?;
+        result = result.checked_mul(10)?.checked_add(x)?;
+    }
+    Some(result)
+}