proxmox-backup-client/src/mount.rs

   1 use std::collections::HashMap;
   2 use std::ffi::OsStr;
   3 use std::hash::BuildHasher;
   4 use std::os::unix::io::AsRawFd;
   5 use std::path::{Path, PathBuf};
   6 use std::sync::Arc;
   7
   8 use anyhow::{bail, format_err, Error};
   9 use futures::future::FutureExt;
  10 use futures::select;
  11 use futures::stream::{StreamExt, TryStreamExt};
  12 use nix::unistd::{fork, ForkResult};
  13 use serde_json::Value;
  14 use tokio::signal::unix::{signal, SignalKind};
  15
  16 use proxmox::{sortable, identity};
  17 use proxmox::api::{ApiHandler, ApiMethod, RpcEnvironment, schema::*, cli::*};
  18 use proxmox::tools::fd::Fd;
  19
  20 use pbs_tools::crypt_config::CryptConfig;
  21 use pbs_config::key_config::load_and_decrypt_key;
  22 use pbs_datastore::{BackupDir, BackupGroup, };
  23 use pbs_datastore::index::IndexFile;
  24 use pbs_datastore::dynamic_index::BufferedDynamicReader;
  25 use pbs_datastore::cached_chunk_reader::CachedChunkReader;
  26 use pbs_client::tools::key_source::get_encryption_key_password;
  27 use pbs_client::{BackupReader, RemoteChunkReader};
  28 use pbs_tools::json::required_string_param;
  29
  30 use crate::{
  31     REPO_URL_SCHEMA,
  32     extract_repository_from_value,
  33     complete_pxar_archive_name,
  34     complete_img_archive_name,
  35     complete_group_or_snapshot,
  36     complete_repository,
  37     record_repository,
  38     connect,
  39     api_datastore_latest_snapshot,
  40     BufferedDynamicReadAt,
  41 };
  42
  43 #[sortable]
  44 const API_METHOD_MOUNT: ApiMethod = ApiMethod::new(
  45     &ApiHandler::Sync(&mount),
  46     &ObjectSchema::new(
  47         "Mount pxar archive.",
  48         &sorted!([
  49             ("snapshot", false, &StringSchema::new("Group/Snapshot path.").schema()),
  50             ("archive-name", false, &StringSchema::new("Backup archive name.").schema()),
  51             ("target", false, &StringSchema::new("Target directory path.").schema()),
  52             ("repository", true, &REPO_URL_SCHEMA),
  53             ("keyfile", true, &StringSchema::new("Path to encryption key.").schema()),
  54             ("verbose", true, &BooleanSchema::new("Verbose output and stay in foreground.").default(false).schema()),
  55         ]),
  56     )
  57 );
  58
  59 #[sortable]
  60 const API_METHOD_MAP: ApiMethod = ApiMethod::new(
  61     &ApiHandler::Sync(&mount),
  62     &ObjectSchema::new(
  63         "Map a drive image from a VM backup to a local loopback device. Use 'unmap' to undo.
  64 WARNING: Only do this with *trusted* backups!",
  65         &sorted!([
  66             ("snapshot", false, &StringSchema::new("Group/Snapshot path.").schema()),
  67             ("archive-name", false, &StringSchema::new("Backup archive name.").schema()),
  68             ("repository", true, &REPO_URL_SCHEMA),
  69             ("keyfile", true, &StringSchema::new("Path to encryption key.").schema()),
  70             ("verbose", true, &BooleanSchema::new("Verbose output and stay in foreground.").default(false).schema()),
  71         ]),
  72     )
  73 );
  74
  75 #[sortable]
  76 const API_METHOD_UNMAP: ApiMethod = ApiMethod::new(
  77     &ApiHandler::Sync(&unmap),
  78     &ObjectSchema::new(
  79         "Unmap a loop device mapped with 'map' and release all resources.",
  80         &sorted!([
  81             ("name", true, &StringSchema::new(
  82                 concat!("Archive name, path to loopdev (/dev/loopX) or loop device number. ",
  83                         "Omit to list all current mappings and force cleaning up leftover instances.")
  84             ).schema()),
  85         ]),
  86     )
  87 );
  88
  89 pub fn mount_cmd_def() -> CliCommand {
  90
  91     CliCommand::new(&API_METHOD_MOUNT)
  92         .arg_param(&["snapshot", "archive-name", "target"])
  93         .completion_cb("repository", complete_repository)
  94         .completion_cb("snapshot", complete_group_or_snapshot)
  95         .completion_cb("archive-name", complete_pxar_archive_name)
  96         .completion_cb("target", pbs_tools::fs::complete_file_name)
  97 }
  98
  99 pub fn map_cmd_def() -> CliCommand {
 100
 101     CliCommand::new(&API_METHOD_MAP)
 102         .arg_param(&["snapshot", "archive-name"])
 103         .completion_cb("repository", complete_repository)
 104         .completion_cb("snapshot", complete_group_or_snapshot)
 105         .completion_cb("archive-name", complete_img_archive_name)
 106 }
 107
 108 pub fn unmap_cmd_def() -> CliCommand {
 109
 110     CliCommand::new(&API_METHOD_UNMAP)
 111         .arg_param(&["name"])
 112         .completion_cb("name", complete_mapping_names)
 113 }
 114
 115 fn complete_mapping_names<S: BuildHasher>(_arg: &str, _param: &HashMap<String, String, S>)
 116     -> Vec<String>
 117 {
 118     match pbs_fuse_loop::find_all_mappings() {
 119         Ok(mappings) => mappings
 120             .filter_map(|(name, _)| {
 121                 proxmox_systemd::unescape_unit(&name).ok()
 122             }).collect(),
 123         Err(_) => Vec::new()
 124     }
 125 }
 126
 127 fn mount(
 128     param: Value,
 129     _info: &ApiMethod,
 130     _rpcenv: &mut dyn RpcEnvironment,
 131 ) -> Result<Value, Error> {
 132
 133     let verbose = param["verbose"].as_bool().unwrap_or(false);
 134     if verbose {
 135         // This will stay in foreground with debug output enabled as None is
 136         // passed for the RawFd.
 137         return pbs_runtime::main(mount_do(param, None));
 138     }
 139
 140     // Process should be daemonized.
 141     // Make sure to fork before the async runtime is instantiated to avoid troubles.
 142     let (pr, pw) = pbs_tools::io::pipe()?;
 143     match unsafe { fork() } {
 144         Ok(ForkResult::Parent { .. }) => {
 145             drop(pw);
 146             // Blocks the parent process until we are ready to go in the child
 147             let _res = nix::unistd::read(pr.as_raw_fd(), &mut [0]).unwrap();
 148             Ok(Value::Null)
 149         }
 150         Ok(ForkResult::Child) => {
 151             drop(pr);
 152             nix::unistd::setsid().unwrap();
 153             pbs_runtime::main(mount_do(param, Some(pw)))
 154         }
 155         Err(_) => bail!("failed to daemonize process"),
 156     }
 157 }
 158
 159 async fn mount_do(param: Value, pipe: Option<Fd>) -> Result<Value, Error> {
 160     let repo = extract_repository_from_value(&param)?;
 161     let archive_name = required_string_param(&param, "archive-name")?;
 162     let client = connect(&repo)?;
 163
 164     let target = param["target"].as_str();
 165
 166     record_repository(&repo);
 167
 168     let path = required_string_param(&param, "snapshot")?;
 169     let (backup_type, backup_id, backup_time) = if path.matches('/').count() == 1 {
 170         let group: BackupGroup = path.parse()?;
 171         api_datastore_latest_snapshot(&client, repo.store(), group).await?
 172     } else {
 173         let snapshot: BackupDir = path.parse()?;
 174         (snapshot.group().backup_type().to_owned(), snapshot.group().backup_id().to_owned(), snapshot.backup_time())
 175     };
 176
 177     let keyfile = param["keyfile"].as_str().map(PathBuf::from);
 178     let crypt_config = match keyfile {
 179         None => None,
 180         Some(path) => {
 181             println!("Encryption key file: '{:?}'", path);
 182             let (key, _, fingerprint) = load_and_decrypt_key(&path, &get_encryption_key_password)?;
 183             println!("Encryption key fingerprint: '{}'", fingerprint);
 184             Some(Arc::new(CryptConfig::new(key)?))
 185         }
 186     };
 187
 188     let server_archive_name = if archive_name.ends_with(".pxar") {
 189         if target.is_none() {
 190             bail!("use the 'mount' command to mount pxar archives");
 191         }
 192         format!("{}.didx", archive_name)
 193     } else if archive_name.ends_with(".img") {
 194         if target.is_some() {
 195             bail!("use the 'map' command to map drive images");
 196         }
 197         format!("{}.fidx", archive_name)
 198     } else {
 199         bail!("Can only mount/map pxar archives and drive images.");
 200     };
 201
 202     let client = BackupReader::start(
 203         client,
 204         crypt_config.clone(),
 205         repo.store(),
 206         &backup_type,
 207         &backup_id,
 208         backup_time,
 209         true,
 210     ).await?;
 211
 212     let (manifest, _) = client.download_manifest().await?;
 213     manifest.check_fingerprint(crypt_config.as_ref().map(Arc::as_ref))?;
 214
 215     let file_info = manifest.lookup_file_info(&server_archive_name)?;
 216
 217     let daemonize = || -> Result<(), Error> {
 218         if let Some(pipe) = pipe {
 219             nix::unistd::chdir(Path::new("/")).unwrap();
 220             // Finish creation of daemon by redirecting filedescriptors.
 221             let nullfd = nix::fcntl::open(
 222                 "/dev/null",
 223                 nix::fcntl::OFlag::O_RDWR,
 224                 nix::sys::stat::Mode::empty(),
 225             ).unwrap();
 226             nix::unistd::dup2(nullfd, 0).unwrap();
 227             nix::unistd::dup2(nullfd, 1).unwrap();
 228             nix::unistd::dup2(nullfd, 2).unwrap();
 229             if nullfd > 2 {
 230                 nix::unistd::close(nullfd).unwrap();
 231             }
 232             // Signal the parent process that we are done with the setup and it can
 233             // terminate.
 234             nix::unistd::write(pipe.as_raw_fd(), &[0u8])?;
 235             let _: Fd = pipe;
 236         }
 237
 238         Ok(())
 239     };
 240
 241     let options = OsStr::new("ro,default_permissions");
 242
 243     // handle SIGINT and SIGTERM
 244     let mut interrupt_int = signal(SignalKind::interrupt())?;
 245     let mut interrupt_term = signal(SignalKind::terminate())?;
 246
 247     let mut interrupt = futures::future::select(interrupt_int.recv().boxed(), interrupt_term.recv().boxed());
 248
 249     if server_archive_name.ends_with(".didx") {
 250         let index = client.download_dynamic_index(&manifest, &server_archive_name).await?;
 251         let most_used = index.find_most_used_chunks(8);
 252         let chunk_reader = RemoteChunkReader::new(client.clone(), crypt_config, file_info.chunk_crypt_mode(), most_used);
 253         let reader = BufferedDynamicReader::new(index, chunk_reader);
 254         let archive_size = reader.archive_size();
 255         let reader: pbs_client::pxar::fuse::Reader =
 256             Arc::new(BufferedDynamicReadAt::new(reader));
 257         let decoder = pbs_client::pxar::fuse::Accessor::new(reader, archive_size).await?;
 258
 259         let session = pbs_client::pxar::fuse::Session::mount(
 260             decoder,
 261             &options,
 262             false,
 263             Path::new(target.unwrap()),
 264         )
 265         .map_err(|err| format_err!("pxar mount failed: {}", err))?;
 266
 267         daemonize()?;
 268
 269         select! {
 270             res = session.fuse() => res?,
 271             _ = interrupt => {
 272                 // exit on interrupted
 273             }
 274         }
 275     } else if server_archive_name.ends_with(".fidx") {
 276         let index = client.download_fixed_index(&manifest, &server_archive_name).await?;
 277         let size = index.index_bytes();
 278         let chunk_reader = RemoteChunkReader::new(client.clone(), crypt_config, file_info.chunk_crypt_mode(), HashMap::new());
 279         let reader = CachedChunkReader::new(chunk_reader, index, 8).seekable();
 280
 281         let name = &format!("{}:{}/{}", repo.to_string(), path, archive_name);
 282         let name_escaped = proxmox_systemd::escape_unit(name, false);
 283
 284         let mut session = pbs_fuse_loop::FuseLoopSession::map_loop(size, reader, &name_escaped, options).await?;
 285         let loopdev = session.loopdev_path.clone();
 286
 287         let (st_send, st_recv) = futures::channel::mpsc::channel(1);
 288         let (mut abort_send, abort_recv) = futures::channel::mpsc::channel(1);
 289         let mut st_recv = st_recv.fuse();
 290         let mut session_fut = session.main(st_send, abort_recv).boxed().fuse();
 291
 292         // poll until loop file is mapped (or errors)
 293         select! {
 294             _res = session_fut => {
 295                 bail!("FUSE session unexpectedly ended before loop file mapping");
 296             },
 297             res = st_recv.try_next() => {
 298                 if let Err(err) = res {
 299                     // init went wrong, abort now
 300                     abort_send.try_send(()).map_err(|err|
 301                         format_err!("error while sending abort signal - {}", err))?;
 302                     // ignore and keep original error cause
 303                     let _ = session_fut.await;
 304                     return Err(err);
 305                 }
 306             }
 307         }
 308
 309         // daemonize only now to be able to print mapped loopdev or startup errors
 310         println!("Image '{}' mapped on {}", name, loopdev);
 311         daemonize()?;
 312
 313         // continue polling until complete or interrupted (which also happens on unmap)
 314         select! {
 315             res = session_fut => res?,
 316             _ = interrupt => {
 317                 // exit on interrupted
 318                 abort_send.try_send(()).map_err(|err|
 319                     format_err!("error while sending abort signal - {}", err))?;
 320                 session_fut.await?;
 321             }
 322         }
 323
 324         println!("Image unmapped");
 325     } else {
 326         bail!("unknown archive file extension (expected .pxar or .img)");
 327     }
 328
 329     Ok(Value::Null)
 330 }
 331
 332 fn unmap(
 333     param: Value,
 334     _info: &ApiMethod,
 335     _rpcenv: &mut dyn RpcEnvironment,
 336 ) -> Result<Value, Error> {
 337
 338     let mut name = match param["name"].as_str() {
 339         Some(name) => name.to_owned(),
 340         None => {
 341             pbs_fuse_loop::cleanup_unused_run_files(None);
 342             let mut any = false;
 343             for (backing, loopdev) in pbs_fuse_loop::find_all_mappings()? {
 344                 let name = proxmox_systemd::unescape_unit(&backing)?;
 345                 println!("{}:\t{}", loopdev.unwrap_or_else(|| "(unmapped)".to_string()), name);
 346                 any = true;
 347             }
 348             if !any {
 349                 println!("Nothing mapped.");
 350             }
 351             return Ok(Value::Null);
 352         },
 353     };
 354
 355     // allow loop device number alone
 356     if let Ok(num) = name.parse::<u8>() {
 357         name = format!("/dev/loop{}", num);
 358     }
 359
 360     if name.starts_with("/dev/loop") {
 361         pbs_fuse_loop::unmap_loopdev(name)?;
 362     } else {
 363         let name = proxmox_systemd::escape_unit(&name, false);
 364         pbs_fuse_loop::unmap_name(name)?;
 365     }
 366
 367     Ok(Value::Null)
 368 }