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 use std::future::Future;
  11 use std::pin::Pin;
  12
  13 use anyhow::{bail, format_err, Error};
  14 use lazy_static::lazy_static;
  15 use log::{error, info};
  16 use tokio::sync::mpsc;
  17 use tokio_stream::wrappers::ReceiverStream;
  18 use http::request::Parts;
  19 use http::Response;
  20 use hyper::{Body, StatusCode};
  21 use hyper::header;
  22
  23 use proxmox::api::RpcEnvironmentType;
  24
  25 use pbs_client::DEFAULT_VSOCK_PORT;
  26 use proxmox_rest_server::{ApiConfig, RestServer, RestEnvironment};
  27
  28 mod proxmox_restore_daemon;
  29 use proxmox_restore_daemon::*;
  30
  31 /// Maximum amount of pending requests. If saturated, virtio-vsock returns ETIMEDOUT immediately.
  32 /// We should never have more than a few requests in queue, so use a low number.
  33 pub const MAX_PENDING: usize = 32;
  34
  35 /// Will be present in base initramfs
  36 pub const VM_DETECT_FILE: &str = "/restore-vm-marker";
  37
  38 lazy_static! {
  39     /// The current disks state. Use for accessing data on the attached snapshots.
  40     pub static ref DISK_STATE: Arc<Mutex<DiskState>> = {
  41         Arc::new(Mutex::new(DiskState::scan().unwrap()))
  42     };
  43 }
  44
  45 /// This is expected to be run by 'proxmox-file-restore' within a mini-VM
  46 fn main() -> Result<(), Error> {
  47     if !Path::new(VM_DETECT_FILE).exists() {
  48         bail!(
  49             "This binary is not supposed to be run manually, use 'proxmox-file-restore' instead."
  50         );
  51     }
  52
  53     // don't have a real syslog (and no persistance), so use env_logger to print to a log file (via
  54     // stdout to a serial terminal attached by QEMU)
  55     env_logger::from_env(env_logger::Env::default().default_filter_or("info"))
  56         .write_style(env_logger::WriteStyle::Never)
  57         .format_timestamp_millis()
  58         .init();
  59
  60     info!("setup basic system environment...");
  61     setup_system_env().map_err(|err| format_err!("system environment setup failed: {}", err))?;
  62
  63     // scan all attached disks now, before starting the API
  64     // this will panic and stop the VM if anything goes wrong
  65     info!("scanning all disks...");
  66     {
  67         let _disk_state = DISK_STATE.lock().unwrap();
  68     }
  69
  70     info!("disk scan complete, starting main runtime...");
  71
  72     pbs_runtime::main(run())
  73 }
  74
  75 /// ensure we have our /run dirs, system users and stuff like that setup
  76 fn setup_system_env() -> Result<(), Error> {
  77     // the API may save some stuff there, e.g., the memcon tracking file
  78     // we do not care much, but it's way less headache to just create it
  79     std::fs::create_dir_all("/run/proxmox-backup")?;
  80
  81     // we now ensure that all lock files are owned by the backup user, and as we reuse the
  82     // specialized REST module from pbs api/daemon we have some checks there for user/acl stuff
  83     // that gets locked, and thus needs the backup system user to work.
  84     std::fs::create_dir_all("/etc")?;
  85     let mut passwd = File::create("/etc/passwd")?;
  86     writeln!(passwd, "root:x:0:0:root:/root:/bin/sh")?;
  87     writeln!(passwd, "backup:x:34:34:backup:/var/backups:/usr/sbin/nologin")?;
  88
  89     let mut group = File::create("/etc/group")?;
  90     writeln!(group, "root:x:0:")?;
  91     writeln!(group, "backup:x:34:")?;
  92
  93     Ok(())
  94 }
  95
  96 fn get_index<'a>(
  97     _env: RestEnvironment,
  98     _parts: Parts,
  99 ) -> Pin<Box<dyn Future<Output = http::Response<Body>> + Send + 'a>> {
 100     Box::pin(async move {
 101
 102         let index = "<center><h1>Proxmox Backup Restore Daemon/h1></center>";
 103
 104         Response::builder()
 105             .status(StatusCode::OK)
 106             .header(header::CONTENT_TYPE, "text/html")
 107             .body(index.into())
 108             .unwrap()
 109     })
 110 }
 111
 112 async fn run() -> Result<(), Error> {
 113     watchdog_init();
 114
 115     let auth_config = Arc::new(
 116         auth::ticket_auth().map_err(|err| format_err!("reading ticket file failed: {}", err))?,
 117     );
 118     let config = ApiConfig::new("", &ROUTER, RpcEnvironmentType::PUBLIC, auth_config, &get_index)?;
 119     let rest_server = RestServer::new(config);
 120
 121     let vsock_fd = get_vsock_fd()?;
 122     let connections = accept_vsock_connections(vsock_fd);
 123     let receiver_stream = ReceiverStream::new(connections);
 124     let acceptor = hyper::server::accept::from_stream(receiver_stream);
 125
 126     hyper::Server::builder(acceptor).serve(rest_server).await?;
 127
 128     bail!("hyper server exited");
 129 }
 130
 131 fn accept_vsock_connections(
 132     vsock_fd: RawFd,
 133 ) -> mpsc::Receiver<Result<tokio::net::UnixStream, Error>> {
 134     use nix::sys::socket::*;
 135     let (sender, receiver) = mpsc::channel(MAX_PENDING);
 136
 137     tokio::spawn(async move {
 138         loop {
 139             let stream: Result<tokio::net::UnixStream, Error> = tokio::task::block_in_place(|| {
 140                 // we need to accept manually, as UnixListener aborts if socket type != AF_UNIX ...
 141                 let client_fd = accept(vsock_fd)?;
 142                 let stream = unsafe { net::UnixStream::from_raw_fd(client_fd) };
 143                 stream.set_nonblocking(true)?;
 144                 tokio::net::UnixStream::from_std(stream).map_err(|err| err.into())
 145             });
 146
 147             match stream {
 148                 Ok(stream) => {
 149                     if sender.send(Ok(stream)).await.is_err() {
 150                         error!("connection accept channel was closed");
 151                     }
 152                 }
 153                 Err(err) => {
 154                     error!("error accepting vsock connetion: {}", err);
 155                 }
 156             }
 157         }
 158     });
 159
 160     receiver
 161 }
 162
 163 fn get_vsock_fd() -> Result<RawFd, Error> {
 164     use nix::sys::socket::*;
 165     let sock_fd = socket(
 166         AddressFamily::Vsock,
 167         SockType::Stream,
 168         SockFlag::empty(),
 169         None,
 170     )?;
 171     let sock_addr = VsockAddr::new(libc::VMADDR_CID_ANY, DEFAULT_VSOCK_PORT as u32);
 172     bind(sock_fd, &SockAddr::Vsock(sock_addr))?;
 173     listen(sock_fd, MAX_PENDING)?;
 174     Ok(sock_fd)
 175 }