src/bin/proxmox-restore-daemon.rs

   1 ///! Daemon binary to run inside a micro-VM for secure single file restore of disk images
   2 use std::fs::File;
   3 use std::io::prelude::*;
   4 use std::os::unix::{
   5     io::{FromRawFd, RawFd},
   6     net,
   7 };
   8 use std::path::Path;
   9 use std::sync::{Arc, Mutex};
  10
  11 use anyhow::{bail, format_err, Error};
  12 use lazy_static::lazy_static;
  13 use log::{error, info};
  14 use tokio::sync::mpsc;
  15 use tokio_stream::wrappers::ReceiverStream;
  16
  17 use proxmox::api::RpcEnvironmentType;
  18
  19 use pbs_client::DEFAULT_VSOCK_PORT;
  20 use proxmox_rest_server::ApiConfig;
  21
  22 use proxmox_backup::server::rest::*;
  23
  24 mod proxmox_restore_daemon;
  25 use proxmox_restore_daemon::*;
  26
  27 /// Maximum amount of pending requests. If saturated, virtio-vsock returns ETIMEDOUT immediately.
  28 /// We should never have more than a few requests in queue, so use a low number.
  29 pub const MAX_PENDING: usize = 32;
  30
  31 /// Will be present in base initramfs
  32 pub const VM_DETECT_FILE: &str = "/restore-vm-marker";
  33
  34 lazy_static! {
  35     /// The current disks state. Use for accessing data on the attached snapshots.
  36     pub static ref DISK_STATE: Arc<Mutex<DiskState>> = {
  37         Arc::new(Mutex::new(DiskState::scan().unwrap()))
  38     };
  39 }
  40
  41 /// This is expected to be run by 'proxmox-file-restore' within a mini-VM
  42 fn main() -> Result<(), Error> {
  43     if !Path::new(VM_DETECT_FILE).exists() {
  44         bail!(
  45             "This binary is not supposed to be run manually, use 'proxmox-file-restore' instead."
  46         );
  47     }
  48
  49     // don't have a real syslog (and no persistance), so use env_logger to print to a log file (via
  50     // stdout to a serial terminal attached by QEMU)
  51     env_logger::from_env(env_logger::Env::default().default_filter_or("info"))
  52         .write_style(env_logger::WriteStyle::Never)
  53         .format_timestamp_millis()
  54         .init();
  55
  56     info!("setup basic system environment...");
  57     setup_system_env().map_err(|err| format_err!("system environment setup failed: {}", err))?;
  58
  59     // scan all attached disks now, before starting the API
  60     // this will panic and stop the VM if anything goes wrong
  61     info!("scanning all disks...");
  62     {
  63         let _disk_state = DISK_STATE.lock().unwrap();
  64     }
  65
  66     info!("disk scan complete, starting main runtime...");
  67
  68     pbs_runtime::main(run())
  69 }
  70
  71 /// ensure we have our /run dirs, system users and stuff like that setup
  72 fn setup_system_env() -> Result<(), Error> {
  73     // the API may save some stuff there, e.g., the memcon tracking file
  74     // we do not care much, but it's way less headache to just create it
  75     std::fs::create_dir_all("/run/proxmox-backup")?;
  76
  77     // we now ensure that all lock files are owned by the backup user, and as we reuse the
  78     // specialized REST module from pbs api/daemon we have some checks there for user/acl stuff
  79     // that gets locked, and thus needs the backup system user to work.
  80     std::fs::create_dir_all("/etc")?;
  81     let mut passwd = File::create("/etc/passwd")?;
  82     writeln!(passwd, "root:x:0:0:root:/root:/bin/sh")?;
  83     writeln!(passwd, "backup:x:34:34:backup:/var/backups:/usr/sbin/nologin")?;
  84
  85     let mut group = File::create("/etc/group")?;
  86     writeln!(group, "root:x:0:")?;
  87     writeln!(group, "backup:x:34:")?;
  88
  89     Ok(())
  90 }
  91
  92 async fn run() -> Result<(), Error> {
  93     watchdog_init();
  94
  95     let auth_config = Arc::new(
  96         auth::ticket_auth().map_err(|err| format_err!("reading ticket file failed: {}", err))?,
  97     );
  98     let config = ApiConfig::new("", &ROUTER, RpcEnvironmentType::PUBLIC, auth_config)?;
  99     let rest_server = RestServer::new(config);
 100
 101     let vsock_fd = get_vsock_fd()?;
 102     let connections = accept_vsock_connections(vsock_fd);
 103     let receiver_stream = ReceiverStream::new(connections);
 104     let acceptor = hyper::server::accept::from_stream(receiver_stream);
 105
 106     hyper::Server::builder(acceptor).serve(rest_server).await?;
 107
 108     bail!("hyper server exited");
 109 }
 110
 111 fn accept_vsock_connections(
 112     vsock_fd: RawFd,
 113 ) -> mpsc::Receiver<Result<tokio::net::UnixStream, Error>> {
 114     use nix::sys::socket::*;
 115     let (sender, receiver) = mpsc::channel(MAX_PENDING);
 116
 117     tokio::spawn(async move {
 118         loop {
 119             let stream: Result<tokio::net::UnixStream, Error> = tokio::task::block_in_place(|| {
 120                 // we need to accept manually, as UnixListener aborts if socket type != AF_UNIX ...
 121                 let client_fd = accept(vsock_fd)?;
 122                 let stream = unsafe { net::UnixStream::from_raw_fd(client_fd) };
 123                 stream.set_nonblocking(true)?;
 124                 tokio::net::UnixStream::from_std(stream).map_err(|err| err.into())
 125             });
 126
 127             match stream {
 128                 Ok(stream) => {
 129                     if sender.send(Ok(stream)).await.is_err() {
 130                         error!("connection accept channel was closed");
 131                     }
 132                 }
 133                 Err(err) => {
 134                     error!("error accepting vsock connetion: {}", err);
 135                 }
 136             }
 137         }
 138     });
 139
 140     receiver
 141 }
 142
 143 fn get_vsock_fd() -> Result<RawFd, Error> {
 144     use nix::sys::socket::*;
 145     let sock_fd = socket(
 146         AddressFamily::Vsock,
 147         SockType::Stream,
 148         SockFlag::empty(),
 149         None,
 150     )?;
 151     let sock_addr = VsockAddr::new(libc::VMADDR_CID_ANY, DEFAULT_VSOCK_PORT as u32);
 152     bind(sock_fd, &SockAddr::Vsock(sock_addr))?;
 153     listen(sock_fd, MAX_PENDING)?;
 154     Ok(sock_fd)
 155 }