proxmox-backup/src/backup/data_blob_writer.rs

172 lines
6.1 KiB
Rust

use anyhow::{Error};
use std::sync::Arc;
use std::io::{Write, Seek, SeekFrom};
use proxmox::tools::io::WriteExt;
use super::*;
enum BlobWriterState<W: Write> {
Uncompressed { csum_writer: ChecksumWriter<W> },
Compressed { compr: zstd::stream::write::Encoder<ChecksumWriter<W>> },
Encrypted { crypt_writer: CryptWriter<ChecksumWriter<W>> },
EncryptedCompressed { compr: zstd::stream::write::Encoder<CryptWriter<ChecksumWriter<W>>> },
}
/// Data blob writer
pub struct DataBlobWriter<W: Write> {
state: BlobWriterState<W>,
}
impl <W: Write + Seek> DataBlobWriter<W> {
pub fn new_uncompressed(mut writer: W) -> Result<Self, Error> {
writer.seek(SeekFrom::Start(0))?;
let head = DataBlobHeader { magic: UNCOMPRESSED_BLOB_MAGIC_1_0, crc: [0; 4] };
unsafe {
writer.write_le_value(head)?;
}
let csum_writer = ChecksumWriter::new(writer, None);
Ok(Self { state: BlobWriterState::Uncompressed { csum_writer }})
}
pub fn new_compressed(mut writer: W) -> Result<Self, Error> {
writer.seek(SeekFrom::Start(0))?;
let head = DataBlobHeader { magic: COMPRESSED_BLOB_MAGIC_1_0, crc: [0; 4] };
unsafe {
writer.write_le_value(head)?;
}
let csum_writer = ChecksumWriter::new(writer, None);
let compr = zstd::stream::write::Encoder::new(csum_writer, 1)?;
Ok(Self { state: BlobWriterState::Compressed { compr }})
}
pub fn new_encrypted(mut writer: W, config: Arc<CryptConfig>) -> Result<Self, Error> {
writer.seek(SeekFrom::Start(0))?;
let head = EncryptedDataBlobHeader {
head: DataBlobHeader { magic: ENCRYPTED_BLOB_MAGIC_1_0, crc: [0; 4] },
iv: [0u8; 16],
tag: [0u8; 16],
};
unsafe {
writer.write_le_value(head)?;
}
let csum_writer = ChecksumWriter::new(writer, None);
let crypt_writer = CryptWriter::new(csum_writer, config)?;
Ok(Self { state: BlobWriterState::Encrypted { crypt_writer }})
}
pub fn new_encrypted_compressed(mut writer: W, config: Arc<CryptConfig>) -> Result<Self, Error> {
writer.seek(SeekFrom::Start(0))?;
let head = EncryptedDataBlobHeader {
head: DataBlobHeader { magic: ENCR_COMPR_BLOB_MAGIC_1_0, crc: [0; 4] },
iv: [0u8; 16],
tag: [0u8; 16],
};
unsafe {
writer.write_le_value(head)?;
}
let csum_writer = ChecksumWriter::new(writer, None);
let crypt_writer = CryptWriter::new(csum_writer, config)?;
let compr = zstd::stream::write::Encoder::new(crypt_writer, 1)?;
Ok(Self { state: BlobWriterState::EncryptedCompressed { compr }})
}
pub fn finish(self) -> Result<W, Error> {
match self.state {
BlobWriterState::Uncompressed { csum_writer } => {
// write CRC
let (mut writer, crc, _) = csum_writer.finish()?;
let head = DataBlobHeader { magic: UNCOMPRESSED_BLOB_MAGIC_1_0, crc: crc.to_le_bytes() };
writer.seek(SeekFrom::Start(0))?;
unsafe {
writer.write_le_value(head)?;
}
Ok(writer)
}
BlobWriterState::Compressed { compr } => {
let csum_writer = compr.finish()?;
let (mut writer, crc, _) = csum_writer.finish()?;
let head = DataBlobHeader { magic: COMPRESSED_BLOB_MAGIC_1_0, crc: crc.to_le_bytes() };
writer.seek(SeekFrom::Start(0))?;
unsafe {
writer.write_le_value(head)?;
}
Ok(writer)
}
BlobWriterState::Encrypted { crypt_writer } => {
let (csum_writer, iv, tag) = crypt_writer.finish()?;
let (mut writer, crc, _) = csum_writer.finish()?;
let head = EncryptedDataBlobHeader {
head: DataBlobHeader { magic: ENCRYPTED_BLOB_MAGIC_1_0, crc: crc.to_le_bytes() },
iv, tag,
};
writer.seek(SeekFrom::Start(0))?;
unsafe {
writer.write_le_value(head)?;
}
Ok(writer)
}
BlobWriterState::EncryptedCompressed { compr } => {
let crypt_writer = compr.finish()?;
let (csum_writer, iv, tag) = crypt_writer.finish()?;
let (mut writer, crc, _) = csum_writer.finish()?;
let head = EncryptedDataBlobHeader {
head: DataBlobHeader { magic: ENCR_COMPR_BLOB_MAGIC_1_0, crc: crc.to_le_bytes() },
iv, tag,
};
writer.seek(SeekFrom::Start(0))?;
unsafe {
writer.write_le_value(head)?;
}
Ok(writer)
}
}
}
}
impl <W: Write + Seek> Write for DataBlobWriter<W> {
fn write(&mut self, buf: &[u8]) -> Result<usize, std::io::Error> {
match self.state {
BlobWriterState::Uncompressed { ref mut csum_writer } => {
csum_writer.write(buf)
}
BlobWriterState::Compressed { ref mut compr } => {
compr.write(buf)
}
BlobWriterState::Encrypted { ref mut crypt_writer } => {
crypt_writer.write(buf)
}
BlobWriterState::EncryptedCompressed { ref mut compr } => {
compr.write(buf)
}
}
}
fn flush(&mut self) -> Result<(), std::io::Error> {
match self.state {
BlobWriterState::Uncompressed { ref mut csum_writer } => {
csum_writer.flush()
}
BlobWriterState::Compressed { ref mut compr } => {
compr.flush()
}
BlobWriterState::Encrypted { ref mut crypt_writer } => {
crypt_writer.flush()
}
BlobWriterState::EncryptedCompressed { ref mut compr } => {
compr.flush()
}
}
}
}