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