proxmox-backup/src/catar/format_definition.rs
2018-12-30 17:32:52 +01:00

81 lines
2.4 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 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;
pub const CA_FORMAT_FEATURE_FLAGS_MAX: u64 = 0xb000_0001_ffef_fe26; // fixme: ?
#[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,
}
#[repr(C)]
pub struct CaFormatEntry {
pub feature_flags: u64,
pub mode: u64,
pub flags: u64,
pub uid: u64,
pub gid: u64,
pub mtime: u64,
}
#[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. repeats the `size`
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()
}