proxmox-backup/proxmox-backup-client/src/mount.rs

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use std::collections::HashMap;
use std::ffi::OsStr;
use std::hash::BuildHasher;
use std::os::unix::io::AsRawFd;
use std::path::{Path, PathBuf};
use std::sync::Arc;
use anyhow::{bail, format_err, Error};
use futures::future::FutureExt;
use futures::select;
use futures::stream::{StreamExt, TryStreamExt};
use nix::unistd::{fork, ForkResult};
use serde_json::Value;
use tokio::signal::unix::{signal, SignalKind};
use proxmox_router::{cli::*, ApiHandler, ApiMethod, RpcEnvironment};
use proxmox_schema::*;
use proxmox_sys::fd::Fd;
use proxmox_sys::sortable;
use pbs_api_types::BackupNamespace;
use pbs_client::tools::key_source::get_encryption_key_password;
use pbs_client::{BackupReader, RemoteChunkReader};
use pbs_config::key_config::load_and_decrypt_key;
use pbs_datastore::cached_chunk_reader::CachedChunkReader;
use pbs_datastore::dynamic_index::BufferedDynamicReader;
use pbs_datastore::index::IndexFile;
use pbs_tools::crypt_config::CryptConfig;
use pbs_tools::json::required_string_param;
use crate::{
complete_group_or_snapshot, complete_img_archive_name, complete_pxar_archive_name,
complete_repository, connect, dir_or_last_from_group, extract_repository_from_value,
optional_ns_param, record_repository, BufferedDynamicReadAt, REPO_URL_SCHEMA,
};
#[sortable]
const API_METHOD_MOUNT: ApiMethod = ApiMethod::new(
&ApiHandler::Sync(&mount),
&ObjectSchema::new(
"Mount pxar archive.",
&sorted!([
("ns", true, &BackupNamespace::API_SCHEMA,),
(
"snapshot",
false,
&StringSchema::new("Group/Snapshot path.").schema()
),
(
"archive-name",
false,
&StringSchema::new("Backup archive name.").schema()
),
(
"target",
false,
&StringSchema::new("Target directory path.").schema()
),
("repository", true, &REPO_URL_SCHEMA),
(
"keyfile",
true,
&StringSchema::new("Path to encryption key.").schema()
),
(
"verbose",
true,
&BooleanSchema::new("Verbose output and stay in foreground.")
.default(false)
.schema()
),
]),
),
);
#[sortable]
const API_METHOD_MAP: ApiMethod = ApiMethod::new(
&ApiHandler::Sync(&mount),
&ObjectSchema::new(
"Map a drive image from a VM backup to a local loopback device. Use 'unmap' to undo.
WARNING: Only do this with *trusted* backups!",
&sorted!([
(
"snapshot",
false,
&StringSchema::new("Group/Snapshot path.").schema()
),
(
"archive-name",
false,
&StringSchema::new("Backup archive name.").schema()
),
("repository", true, &REPO_URL_SCHEMA),
(
"keyfile",
true,
&StringSchema::new("Path to encryption key.").schema()
),
(
"verbose",
true,
&BooleanSchema::new("Verbose output and stay in foreground.")
.default(false)
.schema()
),
]),
),
);
#[sortable]
const API_METHOD_UNMAP: ApiMethod = ApiMethod::new(
&ApiHandler::Sync(&unmap),
&ObjectSchema::new(
"Unmap a loop device mapped with 'map' and release all resources.",
&sorted!([(
"name",
true,
&StringSchema::new(concat!(
"Archive name, path to loopdev (/dev/loopX) or loop device number. ",
"Omit to list all current mappings and force cleaning up leftover instances."
))
.schema()
),]),
),
);
pub fn mount_cmd_def() -> CliCommand {
CliCommand::new(&API_METHOD_MOUNT)
.arg_param(&["snapshot", "archive-name", "target"])
.completion_cb("repository", complete_repository)
.completion_cb("snapshot", complete_group_or_snapshot)
.completion_cb("archive-name", complete_pxar_archive_name)
.completion_cb("target", complete_file_name)
}
pub fn map_cmd_def() -> CliCommand {
CliCommand::new(&API_METHOD_MAP)
.arg_param(&["snapshot", "archive-name"])
.completion_cb("repository", complete_repository)
.completion_cb("snapshot", complete_group_or_snapshot)
.completion_cb("archive-name", complete_img_archive_name)
}
pub fn unmap_cmd_def() -> CliCommand {
CliCommand::new(&API_METHOD_UNMAP)
.arg_param(&["name"])
.completion_cb("name", complete_mapping_names)
}
fn complete_mapping_names<S: BuildHasher>(
_arg: &str,
_param: &HashMap<String, String, S>,
) -> Vec<String> {
match pbs_fuse_loop::find_all_mappings() {
Ok(mappings) => mappings
.filter_map(|(name, _)| proxmox_sys::systemd::unescape_unit(&name).ok())
.collect(),
Err(_) => Vec::new(),
}
}
fn mount(
param: Value,
_info: &ApiMethod,
_rpcenv: &mut dyn RpcEnvironment,
) -> Result<Value, Error> {
let verbose = param["verbose"].as_bool().unwrap_or(false);
if verbose {
// This will stay in foreground with debug output enabled as None is
// passed for the RawFd.
return proxmox_async::runtime::main(mount_do(param, None));
}
// Process should be daemonized.
// Make sure to fork before the async runtime is instantiated to avoid troubles.
let (pr, pw) = proxmox_sys::pipe()?;
match unsafe { fork() } {
Ok(ForkResult::Parent { .. }) => {
drop(pw);
// Blocks the parent process until we are ready to go in the child
let _res = nix::unistd::read(pr.as_raw_fd(), &mut [0]).unwrap();
Ok(Value::Null)
}
Ok(ForkResult::Child) => {
drop(pr);
nix::unistd::setsid().unwrap();
proxmox_async::runtime::main(mount_do(param, Some(pw)))
}
Err(_) => bail!("failed to daemonize process"),
}
}
async fn mount_do(param: Value, pipe: Option<Fd>) -> Result<Value, Error> {
let repo = extract_repository_from_value(&param)?;
let archive_name = required_string_param(&param, "archive-name")?;
let client = connect(&repo)?;
let target = param["target"].as_str();
record_repository(&repo);
let backup_ns = optional_ns_param(&param)?;
let path = required_string_param(&param, "snapshot")?;
let backup_dir = dir_or_last_from_group(&client, &repo, &backup_ns, &path).await?;
let keyfile = param["keyfile"].as_str().map(PathBuf::from);
let crypt_config = match keyfile {
None => None,
Some(path) => {
println!("Encryption key file: '{:?}'", path);
let (key, _, fingerprint) = load_and_decrypt_key(&path, &get_encryption_key_password)?;
println!("Encryption key fingerprint: '{}'", fingerprint);
Some(Arc::new(CryptConfig::new(key)?))
}
};
let server_archive_name = if archive_name.ends_with(".pxar") {
if target.is_none() {
bail!("use the 'mount' command to mount pxar archives");
}
format!("{}.didx", archive_name)
} else if archive_name.ends_with(".img") {
if target.is_some() {
bail!("use the 'map' command to map drive images");
}
format!("{}.fidx", archive_name)
} else {
bail!("Can only mount/map pxar archives and drive images.");
};
let client = BackupReader::start(
client,
crypt_config.clone(),
repo.store(),
&backup_ns,
&backup_dir,
true,
)
.await?;
let (manifest, _) = client.download_manifest().await?;
manifest.check_fingerprint(crypt_config.as_ref().map(Arc::as_ref))?;
let file_info = manifest.lookup_file_info(&server_archive_name)?;
let daemonize = || -> Result<(), Error> {
if let Some(pipe) = pipe {
nix::unistd::chdir(Path::new("/")).unwrap();
// Finish creation of daemon by redirecting filedescriptors.
let nullfd = nix::fcntl::open(
"/dev/null",
nix::fcntl::OFlag::O_RDWR,
nix::sys::stat::Mode::empty(),
)
.unwrap();
nix::unistd::dup2(nullfd, 0).unwrap();
nix::unistd::dup2(nullfd, 1).unwrap();
nix::unistd::dup2(nullfd, 2).unwrap();
if nullfd > 2 {
nix::unistd::close(nullfd).unwrap();
}
// Signal the parent process that we are done with the setup and it can
// terminate.
nix::unistd::write(pipe.as_raw_fd(), &[0u8])?;
let _: Fd = pipe;
}
Ok(())
};
let options = OsStr::new("ro,default_permissions");
// handle SIGINT and SIGTERM
let mut interrupt_int = signal(SignalKind::interrupt())?;
let mut interrupt_term = signal(SignalKind::terminate())?;
let mut interrupt =
futures::future::select(interrupt_int.recv().boxed(), interrupt_term.recv().boxed());
if server_archive_name.ends_with(".didx") {
let index = client
.download_dynamic_index(&manifest, &server_archive_name)
.await?;
let most_used = index.find_most_used_chunks(8);
let chunk_reader = RemoteChunkReader::new(
client.clone(),
crypt_config,
file_info.chunk_crypt_mode(),
most_used,
);
let reader = BufferedDynamicReader::new(index, chunk_reader);
let archive_size = reader.archive_size();
let reader: pbs_client::pxar::fuse::Reader = Arc::new(BufferedDynamicReadAt::new(reader));
let decoder = pbs_client::pxar::fuse::Accessor::new(reader, archive_size).await?;
let session = pbs_client::pxar::fuse::Session::mount(
decoder,
options,
false,
Path::new(target.unwrap()),
)
.map_err(|err| format_err!("pxar mount failed: {}", err))?;
daemonize()?;
select! {
res = session.fuse() => res?,
_ = interrupt => {
// exit on interrupted
}
}
} else if server_archive_name.ends_with(".fidx") {
let index = client
.download_fixed_index(&manifest, &server_archive_name)
.await?;
let size = index.index_bytes();
let chunk_reader = RemoteChunkReader::new(
client.clone(),
crypt_config,
file_info.chunk_crypt_mode(),
HashMap::new(),
);
let reader = CachedChunkReader::new(chunk_reader, index, 8).seekable();
let name = &format!("{}:{}/{}", repo, path, archive_name);
let name_escaped = proxmox_sys::systemd::escape_unit(name, false);
let mut session =
pbs_fuse_loop::FuseLoopSession::map_loop(size, reader, &name_escaped, options).await?;
let loopdev = session.loopdev_path.clone();
let (st_send, st_recv) = futures::channel::mpsc::channel(1);
let (mut abort_send, abort_recv) = futures::channel::mpsc::channel(1);
let mut st_recv = st_recv.fuse();
let mut session_fut = session.main(st_send, abort_recv).boxed().fuse();
// poll until loop file is mapped (or errors)
select! {
_res = session_fut => {
bail!("FUSE session unexpectedly ended before loop file mapping");
},
res = st_recv.try_next() => {
if let Err(err) = res {
// init went wrong, abort now
abort_send.try_send(()).map_err(|err|
format_err!("error while sending abort signal - {}", err))?;
// ignore and keep original error cause
let _ = session_fut.await;
return Err(err);
}
}
}
// daemonize only now to be able to print mapped loopdev or startup errors
println!("Image '{}' mapped on {}", name, loopdev);
daemonize()?;
// continue polling until complete or interrupted (which also happens on unmap)
select! {
res = session_fut => res?,
_ = interrupt => {
// exit on interrupted
abort_send.try_send(()).map_err(|err|
format_err!("error while sending abort signal - {}", err))?;
session_fut.await?;
}
}
println!("Image unmapped");
} else {
bail!("unknown archive file extension (expected .pxar or .img)");
}
Ok(Value::Null)
}
fn unmap(
param: Value,
_info: &ApiMethod,
_rpcenv: &mut dyn RpcEnvironment,
) -> Result<Value, Error> {
let mut name = match param["name"].as_str() {
Some(name) => name.to_owned(),
None => {
pbs_fuse_loop::cleanup_unused_run_files(None);
let mut any = false;
for (backing, loopdev) in pbs_fuse_loop::find_all_mappings()? {
let name = proxmox_sys::systemd::unescape_unit(&backing)?;
println!(
"{}:\t{}",
loopdev.unwrap_or_else(|| "(unmapped)".to_string()),
name
);
any = true;
}
if !any {
println!("Nothing mapped.");
}
return Ok(Value::Null);
}
};
// allow loop device number alone
if let Ok(num) = name.parse::<u8>() {
name = format!("/dev/loop{}", num);
}
if name.starts_with("/dev/loop") {
pbs_fuse_loop::unmap_loopdev(name)?;
} else {
let name = proxmox_sys::systemd::escape_unit(&name, false);
pbs_fuse_loop::unmap_name(name)?;
}
Ok(Value::Null)
}