src/bin/proxmox_backup_client/mount.rs

   1 use std::path::PathBuf;
   2 use std::sync::Arc;
   3 use std::os::unix::io::RawFd;
   4 use std::path::Path;
   5 use std::ffi::OsStr;
   6 use std::collections::HashMap;
   7 use std::hash::BuildHasher;
   8
   9 use anyhow::{bail, format_err, Error};
  10 use serde_json::Value;
  11 use tokio::signal::unix::{signal, SignalKind};
  12 use nix::unistd::{fork, ForkResult, pipe};
  13 use futures::select;
  14 use futures::future::FutureExt;
  15 use futures::stream::{StreamExt, TryStreamExt};
  16
  17 use proxmox::{sortable, identity};
  18 use proxmox::api::{ApiHandler, ApiMethod, RpcEnvironment, schema::*, cli::*};
  19
  20
  21 use proxmox_backup::tools;
  22 use proxmox_backup::backup::{
  23     load_and_decrypt_key,
  24     CryptConfig,
  25     IndexFile,
  26     BackupDir,
  27     BackupGroup,
  28     BufferedDynamicReader,
  29     AsyncIndexReader,
  30 };
  31
  32 use proxmox_backup::client::*;
  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", tools::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 proxmox_backup::tools::runtime::main(mount_do(param, None));
 142     }
 143
 144     // Process should be deamonized.
 145     // Make sure to fork before the async runtime is instantiated to avoid troubles.
 146     let pipe = pipe()?;
 147     match fork() {
 148         Ok(ForkResult::Parent { .. }) => {
 149             nix::unistd::close(pipe.1).unwrap();
 150             // Blocks the parent process until we are ready to go in the child
 151             let _res = nix::unistd::read(pipe.0, &mut [0]).unwrap();
 152             Ok(Value::Null)
 153         }
 154         Ok(ForkResult::Child) => {
 155             nix::unistd::close(pipe.0).unwrap();
 156             nix::unistd::setsid().unwrap();
 157             proxmox_backup::tools::runtime::main(mount_do(param, Some(pipe.1)))
 158         }
 159         Err(_) => bail!("failed to daemonize process"),
 160     }
 161 }
 162
 163 async fn mount_do(param: Value, pipe: Option<RawFd>) -> 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.host(), repo.port(), repo.user())?;
 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             let (key, _) = load_and_decrypt_key(&path, &crate::key::get_encryption_key_password)?;
 186             Some(Arc::new(CryptConfig::new(key)?))
 187         }
 188     };
 189
 190     let server_archive_name = if archive_name.ends_with(".pxar") {
 191         if let None = target {
 192             bail!("use the 'mount' command to mount pxar archives");
 193         }
 194         format!("{}.didx", archive_name)
 195     } else if archive_name.ends_with(".img") {
 196         if let Some(_) = target {
 197             bail!("use the 'map' command to map drive images");
 198         }
 199         format!("{}.fidx", archive_name)
 200     } else {
 201         bail!("Can only mount/map pxar archives and drive images.");
 202     };
 203
 204     let client = BackupReader::start(
 205         client,
 206         crypt_config.clone(),
 207         repo.store(),
 208         &backup_type,
 209         &backup_id,
 210         backup_time,
 211         true,
 212     ).await?;
 213
 214     let (manifest, _) = client.download_manifest().await?;
 215
 216     let file_info = manifest.lookup_file_info(&server_archive_name)?;
 217
 218     let daemonize = || -> Result<(), Error> {
 219         if let Some(pipe) = pipe {
 220             nix::unistd::chdir(Path::new("/")).unwrap();
 221             // Finish creation of daemon by redirecting filedescriptors.
 222             let nullfd = nix::fcntl::open(
 223                 "/dev/null",
 224                 nix::fcntl::OFlag::O_RDWR,
 225                 nix::sys::stat::Mode::empty(),
 226             ).unwrap();
 227             nix::unistd::dup2(nullfd, 0).unwrap();
 228             nix::unistd::dup2(nullfd, 1).unwrap();
 229             nix::unistd::dup2(nullfd, 2).unwrap();
 230             if nullfd > 2 {
 231                 nix::unistd::close(nullfd).unwrap();
 232             }
 233             // Signal the parent process that we are done with the setup and it can
 234             // terminate.
 235             nix::unistd::write(pipe, &[0u8])?;
 236             nix::unistd::close(pipe).unwrap();
 237         }
 238
 239         Ok(())
 240     };
 241
 242     let options = OsStr::new("ro,default_permissions");
 243
 244     // handle SIGINT and SIGTERM
 245     let mut interrupt_int = signal(SignalKind::interrupt())?;
 246     let mut interrupt_term = signal(SignalKind::terminate())?;
 247     let mut interrupt = futures::future::select(interrupt_int.next(), interrupt_term.next());
 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: proxmox_backup::pxar::fuse::Reader =
 256             Arc::new(BufferedDynamicReadAt::new(reader));
 257         let decoder = proxmox_backup::pxar::fuse::Accessor::new(reader, archive_size).await?;
 258
 259         let session = proxmox_backup::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 = AsyncIndexReader::new(index, chunk_reader);
 280
 281         let name = &format!("{}:{}/{}", repo.to_string(), path, archive_name);
 282         let name_escaped = tools::systemd::escape_unit(name, false);
 283
 284         let mut session = tools::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             tools::fuse_loop::cleanup_unused_run_files(None);
 342             let mut any = false;
 343             for (backing, loopdev) in tools::fuse_loop::find_all_mappings()? {
 344                 let name = tools::systemd::unescape_unit(&backing)?;
 345                 println!("{}:\t{}", loopdev.unwrap_or("(unmapped)".to_owned()), 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         tools::fuse_loop::unmap_loopdev(name)?;
 362     } else {
 363         let name = tools::systemd::escape_unit(&name, false);
 364         tools::fuse_loop::unmap_name(name)?;
 365     }
 366
 367     Ok(Value::Null)
 368 }