src/bin/proxmox_backup_client/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_client::tools::key_source::get_encryption_key_password;
  21 use pbs_client::{BackupReader, RemoteChunkReader};
  22
  23 use proxmox_backup::tools;
  24 use proxmox_backup::backup::{
  25     load_and_decrypt_key,
  26     CryptConfig,
  27     IndexFile,
  28     BackupDir,
  29     BackupGroup,
  30     BufferedDynamicReader,
  31     CachedChunkReader,
  32 };
  33
  34 use crate::{
  35     REPO_URL_SCHEMA,
  36     extract_repository_from_value,
  37     complete_pxar_archive_name,
  38     complete_img_archive_name,
  39     complete_group_or_snapshot,
  40     complete_repository,
  41     record_repository,
  42     connect,
  43     api_datastore_latest_snapshot,
  44     BufferedDynamicReadAt,
  45 };
  46
  47 #[sortable]
  48 const API_METHOD_MOUNT: ApiMethod = ApiMethod::new(
  49     &ApiHandler::Sync(&mount),
  50     &ObjectSchema::new(
  51         "Mount pxar archive.",
  52         &sorted!([
  53             ("snapshot", false, &StringSchema::new("Group/Snapshot path.").schema()),
  54             ("archive-name", false, &StringSchema::new("Backup archive name.").schema()),
  55             ("target", false, &StringSchema::new("Target directory path.").schema()),
  56             ("repository", true, &REPO_URL_SCHEMA),
  57             ("keyfile", true, &StringSchema::new("Path to encryption key.").schema()),
  58             ("verbose", true, &BooleanSchema::new("Verbose output and stay in foreground.").default(false).schema()),
  59         ]),
  60     )
  61 );
  62
  63 #[sortable]
  64 const API_METHOD_MAP: ApiMethod = ApiMethod::new(
  65     &ApiHandler::Sync(&mount),
  66     &ObjectSchema::new(
  67         "Map a drive image from a VM backup to a local loopback device. Use 'unmap' to undo.
  68 WARNING: Only do this with *trusted* backups!",
  69         &sorted!([
  70             ("snapshot", false, &StringSchema::new("Group/Snapshot path.").schema()),
  71             ("archive-name", false, &StringSchema::new("Backup archive name.").schema()),
  72             ("repository", true, &REPO_URL_SCHEMA),
  73             ("keyfile", true, &StringSchema::new("Path to encryption key.").schema()),
  74             ("verbose", true, &BooleanSchema::new("Verbose output and stay in foreground.").default(false).schema()),
  75         ]),
  76     )
  77 );
  78
  79 #[sortable]
  80 const API_METHOD_UNMAP: ApiMethod = ApiMethod::new(
  81     &ApiHandler::Sync(&unmap),
  82     &ObjectSchema::new(
  83         "Unmap a loop device mapped with 'map' and release all resources.",
  84         &sorted!([
  85             ("name", true, &StringSchema::new(
  86                 concat!("Archive name, path to loopdev (/dev/loopX) or loop device number. ",
  87                         "Omit to list all current mappings and force cleaning up leftover instances.")
  88             ).schema()),
  89         ]),
  90     )
  91 );
  92
  93 pub fn mount_cmd_def() -> CliCommand {
  94
  95     CliCommand::new(&API_METHOD_MOUNT)
  96         .arg_param(&["snapshot", "archive-name", "target"])
  97         .completion_cb("repository", complete_repository)
  98         .completion_cb("snapshot", complete_group_or_snapshot)
  99         .completion_cb("archive-name", complete_pxar_archive_name)
 100         .completion_cb("target", pbs_tools::fs::complete_file_name)
 101 }
 102
 103 pub fn map_cmd_def() -> CliCommand {
 104
 105     CliCommand::new(&API_METHOD_MAP)
 106         .arg_param(&["snapshot", "archive-name"])
 107         .completion_cb("repository", complete_repository)
 108         .completion_cb("snapshot", complete_group_or_snapshot)
 109         .completion_cb("archive-name", complete_img_archive_name)
 110 }
 111
 112 pub fn unmap_cmd_def() -> CliCommand {
 113
 114     CliCommand::new(&API_METHOD_UNMAP)
 115         .arg_param(&["name"])
 116         .completion_cb("name", complete_mapping_names)
 117 }
 118
 119 fn complete_mapping_names<S: BuildHasher>(_arg: &str, _param: &HashMap<String, String, S>)
 120     -> Vec<String>
 121 {
 122     match tools::fuse_loop::find_all_mappings() {
 123         Ok(mappings) => mappings
 124             .filter_map(|(name, _)| {
 125                 tools::systemd::unescape_unit(&name).ok()
 126             }).collect(),
 127         Err(_) => Vec::new()
 128     }
 129 }
 130
 131 fn mount(
 132     param: Value,
 133     _info: &ApiMethod,
 134     _rpcenv: &mut dyn RpcEnvironment,
 135 ) -> Result<Value, Error> {
 136
 137     let verbose = param["verbose"].as_bool().unwrap_or(false);
 138     if verbose {
 139         // This will stay in foreground with debug output enabled as None is
 140         // passed for the RawFd.
 141         return pbs_runtime::main(mount_do(param, None));
 142     }
 143
 144     // Process should be daemonized.
 145     // Make sure to fork before the async runtime is instantiated to avoid troubles.
 146     let (pr, pw) = proxmox_backup::tools::pipe()?;
 147     match unsafe { fork() } {
 148         Ok(ForkResult::Parent { .. }) => {
 149             drop(pw);
 150             // Blocks the parent process until we are ready to go in the child
 151             let _res = nix::unistd::read(pr.as_raw_fd(), &mut [0]).unwrap();
 152             Ok(Value::Null)
 153         }
 154         Ok(ForkResult::Child) => {
 155             drop(pr);
 156             nix::unistd::setsid().unwrap();
 157             pbs_runtime::main(mount_do(param, Some(pw)))
 158         }
 159         Err(_) => bail!("failed to daemonize process"),
 160     }
 161 }
 162
 163 async fn mount_do(param: Value, pipe: Option<Fd>) -> Result<Value, Error> {
 164     let repo = extract_repository_from_value(&param)?;
 165     let archive_name = tools::required_string_param(&param, "archive-name")?;
 166     let client = connect(&repo)?;
 167
 168     let target = param["target"].as_str();
 169
 170     record_repository(&repo);
 171
 172     let path = tools::required_string_param(&param, "snapshot")?;
 173     let (backup_type, backup_id, backup_time) = if path.matches('/').count() == 1 {
 174         let group: BackupGroup = path.parse()?;
 175         api_datastore_latest_snapshot(&client, repo.store(), group).await?
 176     } else {
 177         let snapshot: BackupDir = path.parse()?;
 178         (snapshot.group().backup_type().to_owned(), snapshot.group().backup_id().to_owned(), snapshot.backup_time())
 179     };
 180
 181     let keyfile = param["keyfile"].as_str().map(PathBuf::from);
 182     let crypt_config = match keyfile {
 183         None => None,
 184         Some(path) => {
 185             println!("Encryption key file: '{:?}'", path);
 186             let (key, _, fingerprint) = load_and_decrypt_key(&path, &get_encryption_key_password)?;
 187             println!("Encryption key fingerprint: '{}'", fingerprint);
 188             Some(Arc::new(CryptConfig::new(key)?))
 189         }
 190     };
 191
 192     let server_archive_name = if archive_name.ends_with(".pxar") {
 193         if target.is_none() {
 194             bail!("use the 'mount' command to mount pxar archives");
 195         }
 196         format!("{}.didx", archive_name)
 197     } else if archive_name.ends_with(".img") {
 198         if target.is_some() {
 199             bail!("use the 'map' command to map drive images");
 200         }
 201         format!("{}.fidx", archive_name)
 202     } else {
 203         bail!("Can only mount/map pxar archives and drive images.");
 204     };
 205
 206     let client = BackupReader::start(
 207         client,
 208         crypt_config.clone(),
 209         repo.store(),
 210         &backup_type,
 211         &backup_id,
 212         backup_time,
 213         true,
 214     ).await?;
 215
 216     let (manifest, _) = client.download_manifest().await?;
 217     manifest.check_fingerprint(crypt_config.as_ref().map(Arc::as_ref))?;
 218
 219     let file_info = manifest.lookup_file_info(&server_archive_name)?;
 220
 221     let daemonize = || -> Result<(), Error> {
 222         if let Some(pipe) = pipe {
 223             nix::unistd::chdir(Path::new("/")).unwrap();
 224             // Finish creation of daemon by redirecting filedescriptors.
 225             let nullfd = nix::fcntl::open(
 226                 "/dev/null",
 227                 nix::fcntl::OFlag::O_RDWR,
 228                 nix::sys::stat::Mode::empty(),
 229             ).unwrap();
 230             nix::unistd::dup2(nullfd, 0).unwrap();
 231             nix::unistd::dup2(nullfd, 1).unwrap();
 232             nix::unistd::dup2(nullfd, 2).unwrap();
 233             if nullfd > 2 {
 234                 nix::unistd::close(nullfd).unwrap();
 235             }
 236             // Signal the parent process that we are done with the setup and it can
 237             // terminate.
 238             nix::unistd::write(pipe.as_raw_fd(), &[0u8])?;
 239             let _: Fd = pipe;
 240         }
 241
 242         Ok(())
 243     };
 244
 245     let options = OsStr::new("ro,default_permissions");
 246
 247     // handle SIGINT and SIGTERM
 248     let mut interrupt_int = signal(SignalKind::interrupt())?;
 249     let mut interrupt_term = signal(SignalKind::terminate())?;
 250
 251     let mut interrupt = futures::future::select(interrupt_int.recv().boxed(), interrupt_term.recv().boxed());
 252
 253     if server_archive_name.ends_with(".didx") {
 254         let index = client.download_dynamic_index(&manifest, &server_archive_name).await?;
 255         let most_used = index.find_most_used_chunks(8);
 256         let chunk_reader = RemoteChunkReader::new(client.clone(), crypt_config, file_info.chunk_crypt_mode(), most_used);
 257         let reader = BufferedDynamicReader::new(index, chunk_reader);
 258         let archive_size = reader.archive_size();
 259         let reader: pbs_client::pxar::fuse::Reader =
 260             Arc::new(BufferedDynamicReadAt::new(reader));
 261         let decoder = pbs_client::pxar::fuse::Accessor::new(reader, archive_size).await?;
 262
 263         let session = pbs_client::pxar::fuse::Session::mount(
 264             decoder,
 265             &options,
 266             false,
 267             Path::new(target.unwrap()),
 268         )
 269         .map_err(|err| format_err!("pxar mount failed: {}", err))?;
 270
 271         daemonize()?;
 272
 273         select! {
 274             res = session.fuse() => res?,
 275             _ = interrupt => {
 276                 // exit on interrupted
 277             }
 278         }
 279     } else if server_archive_name.ends_with(".fidx") {
 280         let index = client.download_fixed_index(&manifest, &server_archive_name).await?;
 281         let size = index.index_bytes();
 282         let chunk_reader = RemoteChunkReader::new(client.clone(), crypt_config, file_info.chunk_crypt_mode(), HashMap::new());
 283         let reader = CachedChunkReader::new(chunk_reader, index, 8).seekable();
 284
 285         let name = &format!("{}:{}/{}", repo.to_string(), path, archive_name);
 286         let name_escaped = tools::systemd::escape_unit(name, false);
 287
 288         let mut session = tools::fuse_loop::FuseLoopSession::map_loop(size, reader, &name_escaped, options).await?;
 289         let loopdev = session.loopdev_path.clone();
 290
 291         let (st_send, st_recv) = futures::channel::mpsc::channel(1);
 292         let (mut abort_send, abort_recv) = futures::channel::mpsc::channel(1);
 293         let mut st_recv = st_recv.fuse();
 294         let mut session_fut = session.main(st_send, abort_recv).boxed().fuse();
 295
 296         // poll until loop file is mapped (or errors)
 297         select! {
 298             _res = session_fut => {
 299                 bail!("FUSE session unexpectedly ended before loop file mapping");
 300             },
 301             res = st_recv.try_next() => {
 302                 if let Err(err) = res {
 303                     // init went wrong, abort now
 304                     abort_send.try_send(()).map_err(|err|
 305                         format_err!("error while sending abort signal - {}", err))?;
 306                     // ignore and keep original error cause
 307                     let _ = session_fut.await;
 308                     return Err(err);
 309                 }
 310             }
 311         }
 312
 313         // daemonize only now to be able to print mapped loopdev or startup errors
 314         println!("Image '{}' mapped on {}", name, loopdev);
 315         daemonize()?;
 316
 317         // continue polling until complete or interrupted (which also happens on unmap)
 318         select! {
 319             res = session_fut => res?,
 320             _ = interrupt => {
 321                 // exit on interrupted
 322                 abort_send.try_send(()).map_err(|err|
 323                     format_err!("error while sending abort signal - {}", err))?;
 324                 session_fut.await?;
 325             }
 326         }
 327
 328         println!("Image unmapped");
 329     } else {
 330         bail!("unknown archive file extension (expected .pxar or .img)");
 331     }
 332
 333     Ok(Value::Null)
 334 }
 335
 336 fn unmap(
 337     param: Value,
 338     _info: &ApiMethod,
 339     _rpcenv: &mut dyn RpcEnvironment,
 340 ) -> Result<Value, Error> {
 341
 342     let mut name = match param["name"].as_str() {
 343         Some(name) => name.to_owned(),
 344         None => {
 345             tools::fuse_loop::cleanup_unused_run_files(None);
 346             let mut any = false;
 347             for (backing, loopdev) in tools::fuse_loop::find_all_mappings()? {
 348                 let name = tools::systemd::unescape_unit(&backing)?;
 349                 println!("{}:\t{}", loopdev.unwrap_or_else(|| "(unmapped)".to_string()), name);
 350                 any = true;
 351             }
 352             if !any {
 353                 println!("Nothing mapped.");
 354             }
 355             return Ok(Value::Null);
 356         },
 357     };
 358
 359     // allow loop device number alone
 360     if let Ok(num) = name.parse::<u8>() {
 361         name = format!("/dev/loop{}", num);
 362     }
 363
 364     if name.starts_with("/dev/loop") {
 365         tools::fuse_loop::unmap_loopdev(name)?;
 366     } else {
 367         let name = tools::systemd::escape_unit(&name, false);
 368         tools::fuse_loop::unmap_name(name)?;
 369     }
 370
 371     Ok(Value::Null)
 372 }