proxmox-backup/src/catar/format_definition.rs

153 lines
4.9 KiB
Rust

//! *catar* binary format definition
//!
//! Please note the all values are stored in little endian ordering.
//!
//! The Archive contains a list of items. Each item starts with a
//! `CaFormatHeader`, followed by the item data.
use failure::*;
use endian_trait::Endian;
use siphasher::sip::SipHasher24;
pub const CA_FORMAT_ENTRY: u64 = 0x1396fabcea5bbb51;
pub const CA_FORMAT_FILENAME: u64 = 0x6dbb6ebcb3161f0b;
pub const CA_FORMAT_SYMLINK: u64 = 0x664a6fb6830e0d6c;
pub const CA_FORMAT_PAYLOAD: u64 = 0x8b9e1d93d6dcffc9;
pub const CA_FORMAT_GOODBYE: u64 = 0xdfd35c5e8327c403;
/* The end marker used in the GOODBYE object */
pub const CA_FORMAT_GOODBYE_TAIL_MARKER: u64 = 0x57446fa533702943;
// Feature flags
// DOS file flags
pub const CA_FORMAT_WITH_FLAG_HIDDEN: u64 = 0x2000;
pub const CA_FORMAT_WITH_FLAG_SYSTEM: u64 = 0x4000;
pub const CA_FORMAT_WITH_FLAG_ARCHIVE: u64 = 0x8000;
// chattr() flags
pub const CA_FORMAT_WITH_FLAG_APPEND: u64 = 0x10000;
pub const CA_FORMAT_WITH_FLAG_NOATIME: u64 = 0x20000;
pub const CA_FORMAT_WITH_FLAG_COMPR: u64 = 0x40000;
pub const CA_FORMAT_WITH_FLAG_NOCOW: u64 = 0x80000;
pub const CA_FORMAT_WITH_FLAG_NODUMP: u64 = 0x100000;
pub const CA_FORMAT_WITH_FLAG_DIRSYNC: u64 = 0x200000;
pub const CA_FORMAT_WITH_FLAG_IMMUTABLE: u64 = 0x400000;
pub const CA_FORMAT_WITH_FLAG_SYNC: u64 = 0x800000;
pub const CA_FORMAT_WITH_FLAG_NOCOMP: u64 = 0x1000000;
pub const CA_FORMAT_WITH_FLAG_PROJINHERIT: u64 = 0x2000000;
pub const CA_FORMAT_FEATURE_FLAGS_MAX: u64 = 0xb000_0001_ffef_fe26; // fixme: ?
#[derive(Endian,Clone)]
#[repr(C)]
pub struct CaFormatHeader {
/// The size of the item, including the size of `CaFormatHeader`.
pub size: u64,
/// The item type (see `CA_FORMAT_` constants).
pub htype: u64,
}
#[derive(Endian,Clone)]
#[repr(C)]
pub struct CaFormatEntry {
pub feature_flags: u64,
pub mode: u64,
pub flags: u64,
pub uid: u64,
pub gid: u64,
pub mtime: u64,
}
#[derive(Endian)]
#[repr(C)]
pub struct CaFormatGoodbyeItem {
/// The offset from the start of the GOODBYE object to the start
/// of the matching directory item (point to a FILENAME). The last
/// GOODBYE item points to the start of the matching ENTRY
/// object.
pub offset: u64,
/// The overall size of the directory item. The last GOODBYE item
/// repeats the size of the GOODBYE item.
pub size: u64,
/// SipHash24 of the directory item name. The last GOODBYE item
/// uses the special hash value `CA_FORMAT_GOODBYE_TAIL_MARKER`.
pub hash: u64,
}
/// Helper function to extract file names from binary archive.
pub fn read_os_string(buffer: &[u8]) -> std::ffi::OsString {
let len = buffer.len();
use std::os::unix::ffi::OsStrExt;
let name = if len > 0 && buffer[len-1] == 0 {
std::ffi::OsStr::from_bytes(&buffer[0..len-1])
} else {
std::ffi::OsStr::from_bytes(&buffer)
};
name.into()
}
/// Create SipHash values for goodby tables.
//pub fn compute_goodbye_hash(name: &std::ffi::CStr) -> u64 {
pub fn compute_goodbye_hash(name: &[u8]) -> u64 {
use std::hash::Hasher;
let mut hasher = SipHasher24::new_with_keys(0x8574442b0f1d84b3, 0x2736ed30d1c22ec1);
hasher.write(name);
hasher.finish()
}
pub fn check_ca_header<T>(head: &CaFormatHeader, htype: u64) -> Result<(), Error> {
if head.htype != htype {
bail!("got wrong header type ({:016x} != {:016x}", head.htype, htype);
}
if head.size != (std::mem::size_of::<T>() + std::mem::size_of::<CaFormatHeader>()) as u64 {
bail!("got wrong header size for type {:016x}", htype);
}
Ok(())
}
// form /usr/include/linux/fs.h
const FS_APPEND_FL: u32 = 0x00000020;
const FS_NOATIME_FL: u32 = 0x00000080;
const FS_COMPR_FL: u32 = 0x00000004;
const FS_NOCOW_FL: u32 = 0x00800000;
const FS_NODUMP_FL: u32 = 0x00000040;
const FS_DIRSYNC_FL: u32 = 0x00010000;
const FS_IMMUTABLE_FL: u32 = 0x00000010;
const FS_SYNC_FL: u32 = 0x00000008;
const FS_NOCOMP_FL: u32 = 0x00000400;
const FS_PROJINHERIT_FL: u32 = 0x20000000;
static CHATTR_MAP: [(u64, u32); 10] = [
( CA_FORMAT_WITH_FLAG_APPEND, FS_APPEND_FL ),
( CA_FORMAT_WITH_FLAG_NOATIME, FS_NOATIME_FL ),
( CA_FORMAT_WITH_FLAG_COMPR, FS_COMPR_FL ),
( CA_FORMAT_WITH_FLAG_NOCOW, FS_NOCOW_FL ),
( CA_FORMAT_WITH_FLAG_NODUMP, FS_NODUMP_FL ),
( CA_FORMAT_WITH_FLAG_DIRSYNC, FS_DIRSYNC_FL ),
( CA_FORMAT_WITH_FLAG_IMMUTABLE, FS_IMMUTABLE_FL ),
( CA_FORMAT_WITH_FLAG_SYNC, FS_SYNC_FL ),
( CA_FORMAT_WITH_FLAG_NOCOMP, FS_NOCOMP_FL ),
( CA_FORMAT_WITH_FLAG_PROJINHERIT, FS_PROJINHERIT_FL ),
];
pub fn ca_feature_flags_from_chattr(attr: u32) -> u64 {
let mut flags = 0u64;
for (ca_flag, fs_flag) in &CHATTR_MAP {
if (attr & fs_flag) != 0 { flags = flags | ca_flag; }
}
flags
}