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//! Support for archive files.
use core::convert::TryInto;
use crate::archive;
use crate::read::{self, Bytes, Error, ReadError, ReadRef};
/// The kind of archive format.
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
#[non_exhaustive]
pub enum ArchiveKind {
/// There are no special files that indicate the archive format.
Unknown,
/// The GNU (or System V) archive format.
Gnu,
/// The GNU (or System V) archive format with 64-bit symbol table.
Gnu64,
/// The BSD archive format.
Bsd,
/// The BSD archive format with 64-bit symbol table.
///
/// This is used for Darwin.
Bsd64,
/// The Windows COFF archive format.
Coff,
/// The AIX big archive format.
AixBig,
}
/// The list of members in the archive.
#[derive(Debug, Clone, Copy)]
enum Members<'data> {
Common {
offset: u64,
end_offset: u64,
},
AixBig {
index: &'data [archive::AixMemberOffset],
},
}
/// A partially parsed archive file.
#[derive(Debug, Clone, Copy)]
pub struct ArchiveFile<'data, R: ReadRef<'data> = &'data [u8]> {
data: R,
kind: ArchiveKind,
members: Members<'data>,
symbols: (u64, u64),
names: &'data [u8],
}
impl<'data, R: ReadRef<'data>> ArchiveFile<'data, R> {
/// Parse the archive header and special members.
pub fn parse(data: R) -> read::Result<Self> {
let len = data.len().read_error("Unknown archive length")?;
let mut tail = 0;
let magic = data
.read_bytes(&mut tail, archive::MAGIC.len() as u64)
.read_error("Invalid archive size")?;
if magic == archive::AIX_BIG_MAGIC {
return Self::parse_aixbig(data);
} else if magic != archive::MAGIC {
return Err(Error("Unsupported archive identifier"));
}
let mut members_offset = tail;
let members_end_offset = len;
let mut file = ArchiveFile {
data,
kind: ArchiveKind::Unknown,
members: Members::Common {
offset: 0,
end_offset: 0,
},
symbols: (0, 0),
names: &[],
};
// The first few members may be special, so parse them.
// GNU has:
// - "/" or "/SYM64/": symbol table (optional)
// - "//": names table (optional)
// COFF has:
// - "/": first linker member
// - "/": second linker member
// - "//": names table
// BSD has:
// - "__.SYMDEF" or "__.SYMDEF SORTED": symbol table (optional)
// BSD 64-bit has:
// - "__.SYMDEF_64" or "__.SYMDEF_64 SORTED": symbol table (optional)
// BSD may use the extended name for the symbol table. This is handled
// by `ArchiveMember::parse`.
if tail < len {
let member = ArchiveMember::parse(data, &mut tail, &[])?;
if member.name == b"/" {
// GNU symbol table (unless we later determine this is COFF).
file.kind = ArchiveKind::Gnu;
file.symbols = member.file_range();
members_offset = tail;
if tail < len {
let member = ArchiveMember::parse(data, &mut tail, &[])?;
if member.name == b"/" {
// COFF linker member.
file.kind = ArchiveKind::Coff;
file.symbols = member.file_range();
members_offset = tail;
if tail < len {
let member = ArchiveMember::parse(data, &mut tail, &[])?;
if member.name == b"//" {
// COFF names table.
file.names = member.data(data)?;
members_offset = tail;
}
}
} else if member.name == b"//" {
// GNU names table.
file.names = member.data(data)?;
members_offset = tail;
}
}
} else if member.name == b"/SYM64/" {
// GNU 64-bit symbol table.
file.kind = ArchiveKind::Gnu64;
file.symbols = member.file_range();
members_offset = tail;
if tail < len {
let member = ArchiveMember::parse(data, &mut tail, &[])?;
if member.name == b"//" {
// GNU names table.
file.names = member.data(data)?;
members_offset = tail;
}
}
} else if member.name == b"//" {
// GNU names table.
file.kind = ArchiveKind::Gnu;
file.names = member.data(data)?;
members_offset = tail;
} else if member.name == b"__.SYMDEF" || member.name == b"__.SYMDEF SORTED" {
// BSD symbol table.
file.kind = ArchiveKind::Bsd;
file.symbols = member.file_range();
members_offset = tail;
} else if member.name == b"__.SYMDEF_64" || member.name == b"__.SYMDEF_64 SORTED" {
// BSD 64-bit symbol table.
file.kind = ArchiveKind::Bsd64;
file.symbols = member.file_range();
members_offset = tail;
} else {
// TODO: This could still be a BSD file. We leave this as unknown for now.
}
}
file.members = Members::Common {
offset: members_offset,
end_offset: members_end_offset,
};
Ok(file)
}
fn parse_aixbig(data: R) -> read::Result<Self> {
let mut tail = 0;
let file_header = data
.read::<archive::AixFileHeader>(&mut tail)
.read_error("Invalid AIX big archive file header")?;
// Caller already validated this.
debug_assert_eq!(file_header.magic, archive::AIX_BIG_MAGIC);
let mut file = ArchiveFile {
data,
kind: ArchiveKind::AixBig,
members: Members::AixBig { index: &[] },
symbols: (0, 0),
names: &[],
};
// Read the span of symbol table.
let symtbl64 = parse_u64_digits(&file_header.gst64off, 10)
.read_error("Invalid offset to 64-bit symbol table in AIX big archive")?;
if symtbl64 > 0 {
// The symbol table is also a file with header.
let member = ArchiveMember::parse_aixbig(data, symtbl64)?;
file.symbols = member.file_range();
} else {
let symtbl = parse_u64_digits(&file_header.gstoff, 10)
.read_error("Invalid offset to symbol table in AIX big archive")?;
if symtbl > 0 {
// The symbol table is also a file with header.
let member = ArchiveMember::parse_aixbig(data, symtbl)?;
file.symbols = member.file_range();
}
}
// Big archive member index table lists file entries with offsets and names.
// To avoid potential infinite loop (members are double-linked list), the
// iterator goes through the index instead of real members.
let member_table_offset = parse_u64_digits(&file_header.memoff, 10)
.read_error("Invalid offset for member table of AIX big archive")?;
if member_table_offset == 0 {
// The offset would be zero if archive contains no file.
return Ok(file);
}
// The member index table is also a file with header.
let member = ArchiveMember::parse_aixbig(data, member_table_offset)?;
let mut member_data = Bytes(member.data(data)?);
// Structure of member index table:
// Number of entries (20 bytes)
// Offsets of each entry (20*N bytes)
// Names string table (the rest of bytes to fill size defined in header)
let members_count_bytes = member_data
.read_slice::<u8>(20)
.read_error("Missing member count in AIX big archive")?;
let members_count = parse_u64_digits(members_count_bytes, 10)
.and_then(|size| size.try_into().ok())
.read_error("Invalid member count in AIX big archive")?;
let index = member_data
.read_slice::<archive::AixMemberOffset>(members_count)
.read_error("Member count overflow in AIX big archive")?;
file.members = Members::AixBig { index };
Ok(file)
}
/// Return the archive format.
#[inline]
pub fn kind(&self) -> ArchiveKind {
self.kind
}
/// Iterate over the members of the archive.
///
/// This does not return special members.
#[inline]
pub fn members(&self) -> ArchiveMemberIterator<'data, R> {
ArchiveMemberIterator {
data: self.data,
members: self.members,
names: self.names,
}
}
}
/// An iterator over the members of an archive.
#[derive(Debug)]
pub struct ArchiveMemberIterator<'data, R: ReadRef<'data> = &'data [u8]> {
data: R,
members: Members<'data>,
names: &'data [u8],
}
impl<'data, R: ReadRef<'data>> Iterator for ArchiveMemberIterator<'data, R> {
type Item = read::Result<ArchiveMember<'data>>;
fn next(&mut self) -> Option<Self::Item> {
match &mut self.members {
Members::Common {
ref mut offset,
ref mut end_offset,
} => {
if *offset >= *end_offset {
return None;
}
let member = ArchiveMember::parse(self.data, offset, self.names);
if member.is_err() {
*offset = *end_offset;
}
Some(member)
}
Members::AixBig { ref mut index } => match **index {
[] => None,
[ref first, ref rest @ ..] => {
*index = rest;
let member = ArchiveMember::parse_aixbig_index(self.data, first);
if member.is_err() {
*index = &[];
}
Some(member)
}
},
}
}
}
/// An archive member header.
#[derive(Debug, Clone, Copy)]
enum MemberHeader<'data> {
/// Common header used by many formats.
Common(&'data archive::Header),
/// AIX big archive header
AixBig(&'data archive::AixHeader),
}
/// A partially parsed archive member.
#[derive(Debug)]
pub struct ArchiveMember<'data> {
header: MemberHeader<'data>,
name: &'data [u8],
offset: u64,
size: u64,
}
impl<'data> ArchiveMember<'data> {
/// Parse the member header, name, and file data in an archive with the common format.
///
/// This reads the extended name (if any) and adjusts the file size.
fn parse<R: ReadRef<'data>>(
data: R,
offset: &mut u64,
names: &'data [u8],
) -> read::Result<Self> {
let header = data
.read::<archive::Header>(offset)
.read_error("Invalid archive member header")?;
if header.terminator != archive::TERMINATOR {
return Err(Error("Invalid archive terminator"));
}
let mut file_offset = *offset;
let mut file_size =
parse_u64_digits(&header.size, 10).read_error("Invalid archive member size")?;
*offset = offset
.checked_add(file_size)
.read_error("Archive member size is too large")?;
// Entries are padded to an even number of bytes.
if (file_size & 1) != 0 {
*offset = offset.saturating_add(1);
}
let name = if header.name[0] == b'/' && (header.name[1] as char).is_ascii_digit() {
// Read file name from the names table.
parse_sysv_extended_name(&header.name[1..], names)
.read_error("Invalid archive extended name offset")?
} else if &header.name[..3] == b"#1/" && (header.name[3] as char).is_ascii_digit() {
// Read file name from the start of the file data.
parse_bsd_extended_name(&header.name[3..], data, &mut file_offset, &mut file_size)
.read_error("Invalid archive extended name length")?
} else if header.name[0] == b'/' {
let name_len = memchr::memchr(b' ', &header.name).unwrap_or(header.name.len());
&header.name[..name_len]
} else {
let name_len = memchr::memchr(b'/', &header.name)
.or_else(|| memchr::memchr(b' ', &header.name))
.unwrap_or(header.name.len());
&header.name[..name_len]
};
Ok(ArchiveMember {
header: MemberHeader::Common(header),
name,
offset: file_offset,
size: file_size,
})
}
/// Parse a member index entry in an AIX big archive,
/// and then parse the member header, name, and file data.
fn parse_aixbig_index<R: ReadRef<'data>>(
data: R,
index: &archive::AixMemberOffset,
) -> read::Result<Self> {
let offset = parse_u64_digits(&index.0, 10)
.read_error("Invalid AIX big archive file member offset")?;
Self::parse_aixbig(data, offset)
}
/// Parse the member header, name, and file data in an AIX big archive.
fn parse_aixbig<R: ReadRef<'data>>(data: R, mut offset: u64) -> read::Result<Self> {
// The format was described at
let header = data
.read::<archive::AixHeader>(&mut offset)
.read_error("Invalid AIX big archive member header")?;
let name_length = parse_u64_digits(&header.namlen, 10)
.read_error("Invalid AIX big archive member name length")?;
let name = data
.read_bytes(&mut offset, name_length)
.read_error("Invalid AIX big archive member name")?;
// The actual data for a file member begins at the first even-byte boundary beyond the
// member header and continues for the number of bytes specified by the ar_size field. The
// ar command inserts null bytes for padding where necessary.
if offset & 1 != 0 {
offset = offset.saturating_add(1);
}
// Because of the even-byte boundary, we have to read and check terminator after header.
let terminator = data
.read_bytes(&mut offset, 2)
.read_error("Invalid AIX big archive terminator")?;
if terminator != archive::TERMINATOR {
return Err(Error("Invalid AIX big archive terminator"));
}
let size = parse_u64_digits(&header.size, 10)
.read_error("Invalid archive member size in AIX big archive")?;
Ok(ArchiveMember {
header: MemberHeader::AixBig(header),
name,
offset,
size,
})
}
/// Return the raw header that is common to many archive formats.
///
/// Returns `None` if this archive does not use the common header format.
#[inline]
pub fn header(&self) -> Option<&'data archive::Header> {
match self.header {
MemberHeader::Common(header) => Some(header),
_ => None,
}
}
/// Return the raw header for AIX big archives.
///
/// Returns `None` if this is not an AIX big archive.
#[inline]
pub fn aix_header(&self) -> Option<&'data archive::AixHeader> {
match self.header {
MemberHeader::AixBig(header) => Some(header),
_ => None,
}
}
/// Return the parsed file name.
///
/// This may be an extended file name.
#[inline]
pub fn name(&self) -> &'data [u8] {
self.name
}
/// Parse the file modification timestamp from the header.
#[inline]
pub fn date(&self) -> Option<u64> {
match &self.header {
MemberHeader::Common(header) => parse_u64_digits(&header.date, 10),
MemberHeader::AixBig(header) => parse_u64_digits(&header.date, 10),
}
}
/// Parse the user ID from the header.
#[inline]
pub fn uid(&self) -> Option<u64> {
match &self.header {
MemberHeader::Common(header) => parse_u64_digits(&header.uid, 10),
MemberHeader::AixBig(header) => parse_u64_digits(&header.uid, 10),
}
}
/// Parse the group ID from the header.
#[inline]
pub fn gid(&self) -> Option<u64> {
match &self.header {
MemberHeader::Common(header) => parse_u64_digits(&header.gid, 10),
MemberHeader::AixBig(header) => parse_u64_digits(&header.gid, 10),
}
}
/// Parse the file mode from the header.
#[inline]
pub fn mode(&self) -> Option<u64> {
match &self.header {
MemberHeader::Common(header) => parse_u64_digits(&header.mode, 8),
MemberHeader::AixBig(header) => parse_u64_digits(&header.mode, 8),
}
}
/// Return the offset and size of the file data.
pub fn file_range(&self) -> (u64, u64) {
(self.offset, self.size)
}
/// Return the file data.
#[inline]
pub fn data<R: ReadRef<'data>>(&self, data: R) -> read::Result<&'data [u8]> {
data.read_bytes_at(self.offset, self.size)
.read_error("Archive member size is too large")
}
}
// Ignores bytes starting from the first space.
fn parse_u64_digits(digits: &[u8], radix: u32) -> Option<u64> {
if let [b' ', ..] = digits {
return None;
}
let mut result: u64 = 0;
for &c in digits {
if c == b' ' {
return Some(result);
} else {
let x = (c as char).to_digit(radix)?;
result = result
.checked_mul(u64::from(radix))?
.checked_add(u64::from(x))?;
}
}
Some(result)
}
fn parse_sysv_extended_name<'data>(digits: &[u8], names: &'data [u8]) -> Result<&'data [u8], ()> {
let offset = parse_u64_digits(digits, 10).ok_or(())?;
let offset = offset.try_into().map_err(|_| ())?;
let name_data = names.get(offset..).ok_or(())?;
let name = match memchr::memchr2(b'/', b'\0', name_data) {
Some(len) => &name_data[..len],
None => name_data,
};
Ok(name)
}
/// Modifies `data` to start after the extended name.
fn parse_bsd_extended_name<'data, R: ReadRef<'data>>(
digits: &[u8],
data: R,
offset: &mut u64,
size: &mut u64,
) -> Result<&'data [u8], ()> {
let len = parse_u64_digits(digits, 10).ok_or(())?;
*size = size.checked_sub(len).ok_or(())?;
let name_data = data.read_bytes(offset, len)?;
let name = match memchr::memchr(b'\0', name_data) {
Some(len) => &name_data[..len],
None => name_data,
};
Ok(name)
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn kind() {
let data = b"!<arch>\n";
let archive = ArchiveFile::parse(&data[..]).unwrap();
assert_eq!(archive.kind(), ArchiveKind::Unknown);
let data = b"\
!<arch>\n\
/ 4 `\n\
0000";
let archive = ArchiveFile::parse(&data[..]).unwrap();
assert_eq!(archive.kind(), ArchiveKind::Gnu);
let data = b"\
!<arch>\n\
// 4 `\n\
0000";
let archive = ArchiveFile::parse(&data[..]).unwrap();
assert_eq!(archive.kind(), ArchiveKind::Gnu);
let data = b"\
!<arch>\n\
/ 4 `\n\
0000\
// 4 `\n\
0000";
let archive = ArchiveFile::parse(&data[..]).unwrap();
assert_eq!(archive.kind(), ArchiveKind::Gnu);
let data = b"\
!<arch>\n\
/SYM64/ 4 `\n\
0000";
let archive = ArchiveFile::parse(&data[..]).unwrap();
assert_eq!(archive.kind(), ArchiveKind::Gnu64);
let data = b"\
!<arch>\n\
/SYM64/ 4 `\n\
0000\
// 4 `\n\
0000";
let archive = ArchiveFile::parse(&data[..]).unwrap();
assert_eq!(archive.kind(), ArchiveKind::Gnu64);
let data = b"\
!<arch>\n\
__.SYMDEF 4 `\n\
0000";
let archive = ArchiveFile::parse(&data[..]).unwrap();
assert_eq!(archive.kind(), ArchiveKind::Bsd);
let data = b"\
!<arch>\n\
#1/9 13 `\n\
__.SYMDEF0000";
let archive = ArchiveFile::parse(&data[..]).unwrap();
assert_eq!(archive.kind(), ArchiveKind::Bsd);
let data = b"\
!<arch>\n\
#1/16 20 `\n\
__.SYMDEF SORTED0000";
let archive = ArchiveFile::parse(&data[..]).unwrap();
assert_eq!(archive.kind(), ArchiveKind::Bsd);
let data = b"\
!<arch>\n\
__.SYMDEF_64 4 `\n\
0000";
let archive = ArchiveFile::parse(&data[..]).unwrap();
assert_eq!(archive.kind(), ArchiveKind::Bsd64);
let data = b"\
!<arch>\n\
#1/12 16 `\n\
__.SYMDEF_640000";
let archive = ArchiveFile::parse(&data[..]).unwrap();
assert_eq!(archive.kind(), ArchiveKind::Bsd64);
let data = b"\
!<arch>\n\
#1/19 23 `\n\
__.SYMDEF_64 SORTED0000";
let archive = ArchiveFile::parse(&data[..]).unwrap();
assert_eq!(archive.kind(), ArchiveKind::Bsd64);
let data = b"\
!<arch>\n\
/ 4 `\n\
0000\
/ 4 `\n\
0000\
// 4 `\n\
0000";
let archive = ArchiveFile::parse(&data[..]).unwrap();
assert_eq!(archive.kind(), ArchiveKind::Coff);
let data = b"\
<bigaf>\n\
0 0 \
0 0 \
0 128 \
6 0 \
0 \0\0\0\0\0\0\0\0\0\0\0\0\
\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\
\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\
\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0";
let archive = ArchiveFile::parse(&data[..]).unwrap();
assert_eq!(archive.kind(), ArchiveKind::AixBig);
}
#[test]
fn gnu_names() {
let data = b"\
!<arch>\n\
// 18 `\n\
0123456789abcdef/\n\
s p a c e/ 0 0 0 644 4 `\n\
0000\
0123456789abcde/0 0 0 644 3 `\n\
odd\n\
/0 0 0 0 644 4 `\n\
even";
let data = &data[..];
let archive = ArchiveFile::parse(data).unwrap();
assert_eq!(archive.kind(), ArchiveKind::Gnu);
let mut members = archive.members();
let member = members.next().unwrap().unwrap();
assert_eq!(member.name(), b"s p a c e");
assert_eq!(member.data(data).unwrap(), &b"0000"[..]);
let member = members.next().unwrap().unwrap();
assert_eq!(member.name(), b"0123456789abcde");
assert_eq!(member.data(data).unwrap(), &b"odd"[..]);
let member = members.next().unwrap().unwrap();
assert_eq!(member.name(), b"0123456789abcdef");
assert_eq!(member.data(data).unwrap(), &b"even"[..]);
assert!(members.next().is_none());
}
#[test]
fn bsd_names() {
let data = b"\
!<arch>\n\
0123456789abcde 0 0 0 644 3 `\n\
odd\n\
#1/16 0 0 0 644 20 `\n\
0123456789abcdefeven";
let data = &data[..];
let archive = ArchiveFile::parse(data).unwrap();
assert_eq!(archive.kind(), ArchiveKind::Unknown);
let mut members = archive.members();
let member = members.next().unwrap().unwrap();
assert_eq!(member.name(), b"0123456789abcde");
assert_eq!(member.data(data).unwrap(), &b"odd"[..]);
let member = members.next().unwrap().unwrap();
assert_eq!(member.name(), b"0123456789abcdef");
assert_eq!(member.data(data).unwrap(), &b"even"[..]);
assert!(members.next().is_none());
}
#[test]
fn aix_names() {
let data = b"\
<bigaf>\n\
396 0 0 \
128 262 0 \
4 262 0 \
1662610370 223 1 644 16 \
0123456789abcdef`\nord\n\
4 396 128 \
1662610374 223 1 644 16 \
fedcba9876543210`\nrev\n\
94 0 262 \
0 0 0 0 0 \
`\n2 128 \
262 0123456789abcdef\0fedcba9876543210\0";
let data = &data[..];
let archive = ArchiveFile::parse(data).unwrap();
assert_eq!(archive.kind(), ArchiveKind::AixBig);
let mut members = archive.members();
let member = members.next().unwrap().unwrap();
assert_eq!(member.name(), b"0123456789abcdef");
assert_eq!(member.data(data).unwrap(), &b"ord\n"[..]);
let member = members.next().unwrap().unwrap();
assert_eq!(member.name(), b"fedcba9876543210");
assert_eq!(member.data(data).unwrap(), &b"rev\n"[..]);
assert!(members.next().is_none());
}
}