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Diffstat (limited to 'vendor/object/src/read/archive.rs')
| -rw-r--r-- | vendor/object/src/read/archive.rs | 759 |
1 files changed, 759 insertions, 0 deletions
diff --git a/vendor/object/src/read/archive.rs b/vendor/object/src/read/archive.rs new file mode 100644 index 0000000..5d4ec4a --- /dev/null +++ b/vendor/object/src/read/archive.rs @@ -0,0 +1,759 @@ +//! Support for archive files. +//! +//! ## Example +//! ```no_run +//! use object::{Object, ObjectSection}; +//! use std::error::Error; +//! use std::fs; +//! +//! /// Reads an archive and displays the name of each member. +//! fn main() -> Result<(), Box<dyn Error>> { +//! # #[cfg(feature = "std")] { +//! let data = fs::read("path/to/binary")?; +//! let file = object::read::archive::ArchiveFile::parse(&*data)?; +//! for member in file.members() { +//! let member = member?; +//! println!("{}", String::from_utf8_lossy(member.name())); +//! } +//! # } +//! Ok(()) +//! } +//! ``` + +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 + // https://www.ibm.com/docs/en/aix/7.3?topic=formats-ar-file-format-big + 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()); + } +} |