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[virt-p2v.git] / virt-p2v.ml

#!/usr/bin/ocamlrun /usr/bin/ocaml
#load "unix.cma";;
#directory "+extlib";;
#load "extLib.cma";;
#directory "+pcre";;
#load "pcre.cma";;

(* virt-p2v.ml is a script which performs a physical to
 * virtual conversion of local disks.
 *
 * Copyright (C) 2007-2008 Red Hat Inc.
 * Written by Richard W.M. Jones <rjones@redhat.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *)

open Unix
open Printf
open ExtList
open ExtString

type state = { greeting : bool;
               remote_host : string option; remote_port : string option;
               transport : transport option;
               remote_directory : string option;
               network : network option;
               devices_to_send : string list option;
               root_filesystem : partition option }
and transport = Server | SSH | TCP
and network = Auto | Shell
and partition = Part of string * string (* eg. "hda", "1" *)
              | LV of string * string   (* eg. "VolGroup00", "LogVol00" *)

(*----------------------------------------------------------------------*)
(* TO MAKE A CUSTOM virt-p2v SCRIPT, adjust the defaults in this section.
 *
 * If left as they are, then this will create a generic virt-p2v script
 * which asks the user for each question.  If you set the defaults here
 * then you will get a custom virt-p2v which is partially or even fully
 * automated and won't ask the user any questions.
 *
 * Note that 'None' means 'no default' (ie. ask the user) whereas
 * 'Some foo' means use 'foo' as the answer.
 *)
let defaults = {
  (* If greeting is true, wait for keypress after boot and during
   * final verification.  Set to 'false' for less interactions.
   *)
  greeting = true;

  (* Transport: Set to 'Some Server' or 'Some SSH' or 'Some TCP' to
   * assume Server, SSH or TCP transports respectively.
   *)
  transport = None;

  (* Remote host and port.  Set to 'Some "host"' and 'Some "port"',
   * else ask the user.
   *)
  remote_host = None;
  remote_port = None;

  (* Remote directory (only for SSH transport).  Set to 'Some "path"'
   * to set up a directory path, else ask the user.
   *)
  remote_directory = None;

  (* List of devices to send.  Set to 'Some ["sda"; "sdb"]' for
   * example to select /dev/sda and /dev/sdb.
   *)
  devices_to_send = None;

  (* The root filesystem containing /etc/fstab.  Set to
   * 'Some (Part ("sda", "3"))' or 'Some (LV ("VolGroup00", "LogVol00"))'
   * for example, else ask user.
   *)
  root_filesystem = None;

  (* Network configuration: Set to 'Some Auto' (try to set it up
   * automatically, or 'Some Shell' (give the user a shell).
   *)
  network = None;
}
(* END OF CUSTOM virt-p2v SCRIPT SECTION.                               *)
(*----------------------------------------------------------------------*)

(* General helper functions. *)

let sort_uniq ?(cmp = compare) xs =     (* sort and uniq a list *)
  let xs = List.sort ~cmp xs in
  let rec loop = function
    | [] -> [] | [x] -> [x]
    | x1 :: x2 :: xs when x1 = x2 -> loop (x1 :: xs)
    | x :: xs -> x :: loop xs
  in
  loop xs

let input_all_lines chan =
  let lines = ref [] in
  try
    while true do lines := input_line chan :: !lines done; []
  with
    End_of_file -> List.rev !lines

let rec string_of_state state =
  sprintf
    "greeting: %b  remote: %s:%s%s%s  network: %s  devices: [%s]  root: %s"
    state.greeting
    (Option.default "" state.remote_host)
    (Option.default "" state.remote_port)
    (match state.transport with
     | None -> ""
     | Some Server -> " (server)" | Some SSH -> " (ssh)" | Some TCP -> " (tcp)")
    (match state.remote_directory with
     | None -> "" | Some dir -> " " ^ dir)
    (match state.network with
     | None -> "none" | Some Auto -> "auto" | Some Shell -> "shell")
    (String.concat "; " (Option.default [] state.devices_to_send))
    (Option.map_default dev_of_partition "" state.root_filesystem)

and dev_of_partition = function
  | Part (dev, partnum) -> sprintf "/dev/%s%s" dev partnum
  | LV (vg, lv) -> sprintf "/dev/%s/%s" vg lv

type dialog_status = Yes of string list | No | Help | Back | Error

type ask_result = Next of state | Prev | Ask_again

(* Dialog functions.
 *
 * Each function takes some common parameters (eg. ~title) and some
 * dialog-specific parameters.
 *
 * Returns the exit status (Yes lines | No | Help | Back | Error).
 *)
let msgbox, yesno, inputbox, radiolist, checklist =
  (* Internal function to actually run the "dialog" shell command. *)
  let run_dialog cparams params =
    let params = cparams @ params in
    eprintf "dialog %s\n%!"
      (String.concat " " (List.map (sprintf "%S") params));

    (* 'dialog' writes its output/result to stderr, so we need to take
     * special steps to capture that - in other words, manual pipe/fork.
     *)
    let rfd, wfd = pipe () in
    match fork () with
    | 0 ->                              (* child, runs dialog *)
        close rfd;
        dup2 wfd stderr;                (* capture stderr to pipe *)
        execvp "dialog" (Array.of_list ("dialog" :: params))
    | pid ->                            (* parent *)
        close wfd;
        let chan = in_channel_of_descr rfd in
        let result = input_all_lines chan in
        close rfd;
        eprintf "dialog result: %S\n%!" (String.concat "\n" result);
        match snd (wait ()) with
        | WEXITED 0 -> Yes result       (* something selected / entered *)
        | WEXITED 1 -> No               (* cancel / no button *)
        | WEXITED 2 -> Help             (* help pressed *)
        | WEXITED 3 -> Back             (* back button *)
        | WEXITED _ -> Error            (* error or Esc *)
        | WSIGNALED i -> failwith (sprintf "dialog: killed by signal %d" i)
        | WSTOPPED i -> failwith (sprintf "dialog: stopped by signal %d" i)
  in

  (* Handle the common parameters.  Note Continuation Passing Style. *)
  let with_common cont ?(cancel=false) ?(backbutton=true) title =
    let params = ["--title"; title] in
    let params = if not cancel then "--nocancel" :: params else params in
    let params =
      if backbutton then "--extra-button" :: "--extra-label" :: "Back" :: params
      else params in
    cont params
  in

  (* Message box and yes/no box. *)
  let rec msgbox =
    with_common (
      fun cparams text height width ->
        run_dialog cparams
          [ "--msgbox"; text; string_of_int height; string_of_int width ]
    )
  and yesno =
    with_common (
      fun cparams text height width ->
        run_dialog cparams
          [ "--yesno"; text; string_of_int height; string_of_int width ]
    )

  (* Simple input box. *)
  and inputbox =
    with_common (
      fun cparams text height width default ->
        run_dialog cparams
          [ "--inputbox"; text; string_of_int height; string_of_int width;
            default ]
    )

  (* Radio list and check list. *)
  and radiolist =
    with_common (
      fun cparams text height width listheight items ->
        let items = List.map (
          function
          | tag, item, true -> [ tag; item; "on" ]
          | tag, item, false -> [ tag; item; "off" ]
        ) items in
        let items = List.concat items in
        let items = "--single-quoted" ::
          "--radiolist" :: text ::
          string_of_int height :: string_of_int width ::
          string_of_int listheight :: items in
        run_dialog cparams items
    )
  and checklist =
    with_common (
      fun cparams text height width listheight items ->
        let items = List.map (
          function
          | tag, item, true -> [ tag; item; "on" ]
          | tag, item, false -> [ tag; item; "off" ]
        ) items in
        let items = List.concat items in
        let items = "--separate-output" ::
          "--checklist" :: text ::
          string_of_int height :: string_of_int width ::
          string_of_int listheight :: items in
        run_dialog cparams items
    )
  in
  msgbox, yesno, inputbox, radiolist, checklist

(* Print failure dialog and exit. *)
let fail_dialog text =
  let text = "\n" ^ text ^ "\n\nIf you want to report this error, there is a shell on [ALT] [F2], log in as root with no password.\n\nPlease provide the contents of /tmp/virt-p2v.log and output of the 'dmesg' command." in
  ignore (msgbox "Error" text 17 50);
  exit 1

(* Shell-safe quoting function.  In fact there's one in stdlib so use it. *)
let quote = Filename.quote

(* Run a shell command and check it returns 0. *)
let sh cmd =
  eprintf "sh: %s\n%!" cmd;
  if Sys.command cmd <> 0 then fail_dialog (sprintf "Command failed:\n\n%s" cmd)

let shfailok cmd =
  eprintf "shfailok: %s\n%!" cmd;
  ignore (Sys.command cmd)

let shwithstatus cmd =
  eprintf "shwithstatus: %s\n%!" cmd;
  Sys.command cmd

(* Same as `cmd` in shell.  Any error message will be in the logfile. *)
let shget cmd =
  eprintf "shget: %s\n%!" cmd;
  let chan = open_process_in cmd in
  let lines = input_all_lines chan in
  match close_process_in chan with
  | WEXITED 0 -> Some lines             (* command succeeded *)
  | WEXITED _ -> None                   (* command failed *)
  | WSIGNALED i -> failwith (sprintf "shget: command killed by signal %d" i)
  | WSTOPPED i -> failwith (sprintf "shget: command stopped by signal %d" i)

(* Start an interactive shell. *)
let shell () =
  shfailok "PS1='\\u@\\h:\\w\\$ ' bash"

(* Some true if is dir/file, Some false if not, None if not found. *)
let is_dir path =
  try Some ((stat path).st_kind = S_DIR)
  with Unix_error (ENOENT, "stat", _) -> None
let is_file path =
  try Some ((stat path).st_kind = S_REG)
  with Unix_error (ENOENT, "stat", _) -> None

(* Useful regular expression. *)
let whitespace = Pcre.regexp "[ \t]+"

(* Generate a predictable safe name containing only letters, numbers
 * and underscores.  If passed a string with no letters or numbers,
 * generates "_1", "_2", etc.
 *)
let safe_name =
  let next_anon =
    let i = ref 0 in
    fun () -> incr i; "_" ^ string_of_int !i
  in
  fun name ->
    let is_safe = function 'a'..'z'|'A'..'Z'|'0'..'9' -> true | _ -> false in
    let name = String.copy name in
    let have_safe = ref false in
    for i = 0 to String.length name - 1 do
      if not (is_safe name.[i]) then name.[i] <- '_' else have_safe := true
    done;
    if !have_safe then name else next_anon ()

type block_device = string * int64      (* "hda" & size in bytes *)

(* Parse the output of 'lvs' to get list of LV names, sizes,
 * corresponding PVs, etc.  Returns a list of (lvname, PVs, lvsize).
 *)
let get_lvs =
  let devname = Pcre.regexp "^/dev/(.+)\\(.+\\)$" in

  function () ->
    match
    shget "lvs --noheadings -o vg_name,lv_name,devices,lv_size"
    with
    | None -> []
    | Some lines ->
        let lines = List.map (Pcre.split ~rex:whitespace) lines in
        List.map (
          function
          | [vg; lv; pvs; lvsize]
          | [_; vg; lv; pvs; lvsize] ->
              let pvs = String.nsplit pvs "," in
              let pvs = List.filter_map (
                fun pv ->
                  try
                    let subs = Pcre.exec ~rex:devname pv in
                    Some (Pcre.get_substring subs 1)
                  with
                    Not_found ->
                      eprintf "lvs: unexpected device name: %s\n%!" pv;
                      None
              ) pvs in
              LV (vg, lv), pvs, lvsize
          | line ->
              failwith ("lvs: unexpected output: " ^ String.concat "," line)
        ) lines

(* Get the partitions on a block device.
 * eg. "sda" -> [Part ("sda","1"); Part ("sda", "2")]
 *)
let get_partitions dev =
  let rex = Pcre.regexp ("^" ^ dev ^ "(.+)$") in
  let devdir = "/sys/block/" ^ dev in
  let parts = Sys.readdir devdir in
  let parts = Array.to_list parts in
  let parts = List.filter (
    fun name -> Some true = is_dir (devdir ^ "/" ^ name)
  ) parts in
  let parts = List.filter_map (
    fun part ->
      try
        let subs = Pcre.exec ~rex part in
        Some (Part (dev, Pcre.get_substring subs 1))
      with
        Not_found -> None
  ) parts in
  parts

(* Generate snapshot device name from device name. *)
let snapshot_name dev =
  "snap" ^ (safe_name dev)

(* Perform a device-mapper snapshot with ramdisk overlay. *)
let snapshot =
  let next_free_ram_disk =
    let i = ref 0 in
    fun () -> incr i; "/dev/ram" ^ string_of_int !i
  in
  fun origin_dev snapshot_dev ->
    let ramdisk = next_free_ram_disk () in
    let sectors =
      let cmd = "blockdev --getsz " ^ quote ("/dev/" ^ origin_dev) in
      let lines = shget cmd in
      match lines with
      | Some (sectors::_) -> Int64.of_string sectors
      | Some [] | None ->
          fail_dialog (sprintf "Snapshot failed - unable to read the size in sectors of block device %s" origin_dev) in

    (* Create the snapshot origin device.  Called, eg. snap_sda1_org *)
    sh (sprintf "dmsetup create %s_org --table='0 %Ld snapshot-origin /dev/%s'"
          snapshot_dev sectors origin_dev);
    (* Create the snapshot. *)
    sh (sprintf "dmsetup create %s --table='0 %Ld snapshot /dev/mapper/%s_org %s n 64'"
          snapshot_dev sectors snapshot_dev ramdisk)

(* Try to perform automatic network configuration, assuming a Fedora or RHEL-
 * like root filesystem mounted on /mnt/root.
 *)
let auto_network state =
  (* Fedora gives an error if this file doesn't exist. *)
  sh "touch /etc/resolv.conf";

  chdir "/etc/sysconfig";

  sh "mv network network.saved";
  sh "mv networking networking.saved";
  sh "mv network-scripts network-scripts.saved";

  (* Originally I symlinked these, but that causes dhclient to
   * keep open /mnt/root (as its cwd is in network-scripts subdir).
   * So now we will copy them recursively instead.
   *)
  sh "cp -r /mnt/root/etc/sysconfig/network .";
  sh "cp -r /mnt/root/etc/sysconfig/networking .";
  sh "cp -r /mnt/root/etc/sysconfig/network-scripts .";

  let status = shwithstatus "/etc/init.d/network start" in

  sh "rm -rf network networking network-scripts";
  sh "mv network.saved network";
  sh "mv networking.saved networking";
  sh "mv network-scripts.saved network-scripts";

  chdir "/tmp";

  (* Try to ping the remote host to see if this worked. *)
  shfailok ("ping -c 3 " ^ Option.map_default quote "" state.remote_host);

  if state.greeting then (
    printf "\n\nDid automatic network configuration work?\n";
    printf "Hint: If not sure, there is a shell on console [ALT] [F2]\n";
    printf "    (y/n) %!";
    let line = read_line () in
    String.length line > 0 && (line.[0] = 'y' || line.[0] = 'Y')
  )
  else
    (* Non-interactive: return the status of /etc/init.d/network start. *)
    status = 0

(* Map local device names to remote devices names.  At the moment we
 * just change sd* to hd* (as device names appear under fullvirt).  In
 * future, lots of complex possibilities.
 *)
let remote_of_origin_dev =
  let devsd = Pcre.regexp "^sd([[:alpha:]]+[[:digit:]]*)$" in
  let devsd_subst = Pcre.subst "hd$1" in
  fun dev ->
    Pcre.replace ~rex:devsd ~itempl:devsd_subst dev

(* Rewrite /mnt/root/etc/fstab. *)
let rewrite_fstab state devices_to_send =
  let filename = "/mnt/root/etc/fstab" in
  if is_file filename = Some true then (
    sh ("cp " ^ quote filename ^ " " ^ quote (filename ^ ".p2vsaved"));

    let chan = open_in filename in
    let lines = input_all_lines chan in
    close_in chan;
    let lines = List.map (Pcre.split ~rex:whitespace) lines in
    let lines = List.map (
      function
      | dev :: rest when String.starts_with dev "/dev/" ->
          let dev = String.sub dev 5 (String.length dev - 5) in
          let dev = remote_of_origin_dev dev in
          let dev = "/dev/" ^ dev in
          dev :: rest
      | line -> line
    ) lines in

    let chan = open_out filename in
    List.iter (
      function
      | [dev; mountpoint; fstype; options; freq; passno] ->
          fprintf chan "%-23s %-23s %-7s %-15s %s %s\n"
            dev mountpoint fstype options freq passno
      | line ->
          output_string chan (String.concat " " line)
    ) lines;
    close_out chan
  )

(* Main entry point. *)
let rec main ttyname =
  (* Running from an init script.  We don't have much of a
   * login environment, so set one up.
   *)
  putenv "PATH"
    (String.concat ":"
       ["/usr/sbin"; "/sbin"; "/usr/local/bin"; "/usr/kerberos/bin";
        "/usr/bin"; "/bin"]);
  putenv "HOME" "/root";
  putenv "LOGNAME" "root";

  (* We can safely write in /tmp (it's a synthetic live CD directory). *)
  chdir "/tmp";

  (* Set up logging to /tmp/virt-p2v.log. *)
  let fd = openfile "virt-p2v.log" [ O_WRONLY; O_APPEND; O_CREAT ] 0o644 in
  dup2 fd stderr;
  close fd;

  (* Log the start up time. *)
  eprintf "\n\n**************************************************\n\n";
  let tm = localtime (time ()) in
  eprintf "virt-p2v-ng starting up at %04d-%02d-%02d %02d:%02d:%02d\n\n%!"
    (tm.tm_year+1900) (tm.tm_mon+1) tm.tm_mday tm.tm_hour tm.tm_min tm.tm_sec;

  (* Connect stdin/stdout to the tty. *)
  (match ttyname with
   | None -> ()
   | Some ttyname ->
       let fd = openfile ("/dev/" ^ ttyname) [ O_RDWR ] 0 in
       dup2 fd stdin;
       dup2 fd stdout;
       close fd);
  printf "virt-p2v.ml starting up ...\n%!";

  (* Search for all non-removable block devices.  Do this early and bail
   * if we can't find anything.  This is a list of strings, like "hda".
   *)
  let all_block_devices : block_device list =
    let rex = Pcre.regexp "^[hs]d" in
    let devices = Array.to_list (Sys.readdir "/sys/block") in
    let devices = List.sort devices in
    let devices = List.filter (fun d -> Pcre.pmatch ~rex d) devices in
    eprintf "all_block_devices: block devices: %s\n%!"
      (String.concat "; " devices);
    (* Run blockdev --getsize64 on each, and reject any where this fails
     * (probably removable devices).
     *)
    let devices = List.filter_map (
      fun d ->
        let cmd = "blockdev --getsize64 " ^ quote ("/dev/" ^ d) in
        let lines = shget cmd in
        match lines with
        | Some (blksize::_) -> Some (d, Int64.of_string blksize)
        | Some [] | None -> None
    ) devices in
    eprintf "all_block_devices: non-removable block devices: %s\n%!"
      (String.concat "; "
         (List.map (fun (d, b) -> sprintf "%s [%Ld]" d b) devices));
    if devices = [] then
      fail_dialog "No non-removable block devices (hard disks, etc.) could be found on this machine.";
    devices in

  (* Search for partitions and LVs (anything that could contain a
   * filesystem directly).  We refer to these generically as
   * "partitions".
   *)
  let all_partitions : partition list =
    (* LVs & PVs. *)
    let lvs, pvs =
      let lvs = get_lvs () in
      let pvs = List.map (fun (_, pvs, _) -> pvs) lvs in
      let pvs = List.concat pvs in
      let pvs = sort_uniq pvs in
      eprintf "all_partitions: PVs: %s\n%!" (String.concat "; " pvs);
      let lvs = List.map (fun (lvname, _, _) -> lvname) lvs in
      eprintf "all_partitions: LVs: %s\n%!"
        (String.concat "; " (List.map dev_of_partition lvs));
      lvs, pvs in

    (* Partitions (eg. "sda1", "sda2"). *)
    let parts =
      let parts = List.map fst all_block_devices in
      let parts = List.map get_partitions parts in
      let parts = List.concat parts in
      eprintf "all_partitions: all partitions: %s\n%!"
        (String.concat "; " (List.map dev_of_partition parts));

      (* Remove any partitions which are PVs. *)
      let parts = List.filter (
        function
        | Part (dev, partnum) -> not (List.mem (dev ^ partnum) pvs)
        | LV _ -> assert false
      ) parts in
      parts in
    eprintf "all_partitions: partitions after removing PVs: %s\n%!"
      (String.concat "; " (List.map dev_of_partition parts));

    (* Concatenate LVs & Parts *)
    lvs @ parts in

  (* Dialogs. *)
  let ask_greeting state =
    ignore (msgbox "virt-p2v" "\nUPDATED! Welcome to virt-p2v, a live CD for migrating a physical machine to a virtualized host.\n\nTo continue press the Return key.\n\nTo get a shell you can use [ALT] [F2] and log in as root with no password.\n\nExtra information is logged in /tmp/virt-p2v.log but this file disappears when the machine reboots." 18 50);
    Next state
  in

  let ask_transport state =
    match
    radiolist "Connection type" ~backbutton:false
      "Connection type.  If possible, select 'server' and run P2V server on the remote host"
      11 50 3 [
        "server", "P2V server on remote host",
          state.transport = Some Server;
        "ssh", "SSH (secure shell)",
          state.transport = Some SSH;
        "tcp", "TCP socket",
          state.transport = Some TCP
      ]
    with
    | Yes ("server"::_) -> Next { state with transport = Some Server }
    | Yes ("ssh"::_) -> Next { state with transport = Some SSH }
    | Yes ("tcp"::_) -> Next { state with transport = Some TCP }
    | Yes _ | No | Help | Error -> Ask_again
    | Back -> Prev
  in

  let ask_hostname state =
    match
    inputbox "Remote host" "Remote host" 10 50
      (Option.default "" state.remote_host)
    with
    | Yes [] -> Ask_again
    | Yes (hostname::_) -> Next { state with remote_host = Some hostname }
    | No | Help | Error -> Ask_again
    | Back -> Prev
  in

  let ask_port state =
    match
    inputbox "Remote port" "Remote port" 10 50
      (Option.default "" state.remote_port)
    with
    | Yes [] ->
        (match state.transport with
         | Some SSH -> Next { state with remote_port = Some "22" }
         | _ -> Next { state with remote_port = Some "16211" }
        )
    | Yes (port::_) -> Next { state with remote_port = Some port }
    | No | Help | Error -> Ask_again
    | Back -> Prev
  in

  let ask_directory state =
    match
    inputbox "Remote directory" "Remote directory" 10 50
      (Option.default "" state.remote_directory)
    with
    | Yes [] ->
        Next { state with remote_directory = Some "/var/lib/xen/images" }
    | Yes (dir::_) -> Next { state with remote_directory = Some dir }
    | No | Help | Error -> Ask_again
    | Back -> Prev
  in

  let ask_network state =
    match
    radiolist "Network configuration" "Network configuration" 10 50 2 [
      "auto", "Automatic configuration", state.network = Some Auto;
      "sh", "Configure from the shell", state.network = Some Shell;
    ]
    with
    | Yes ("auto"::_) -> Next { state with network = Some Auto }
    | Yes ("sh"::_) -> Next { state with network = Some Shell }
    | Yes _ | No | Help | Error -> Ask_again
    | Back -> Prev
  in

  let ask_devices state =
    let selected_devices = Option.default [] state.devices_to_send in
    let devices = List.map (
      fun (dev, blksize) ->
        (dev,
         sprintf "/dev/%s (%.3f GB)" dev
           ((Int64.to_float blksize) /. (1024.*.1024.*.1024.)),
         List.mem dev selected_devices)
    ) all_block_devices in
    match
    checklist "Devices" "Pick devices to send" 15 50 8 devices
    with
    | Yes [] | No | Help | Error -> Ask_again
    | Yes devices -> Next { state with devices_to_send = Some devices }
    | Back -> Prev
  in

  let ask_root state =
    let parts = List.mapi (
      fun i part ->
        (string_of_int i, dev_of_partition part,
         Some part = state.root_filesystem)
    ) all_partitions in
    match
    radiolist "Root device"
      "Pick partition containing the root (/) filesystem" 15 50 6
      parts
    with
    | Yes (i::_) ->
        let part = List.nth all_partitions (int_of_string i) in
        Next { state with root_filesystem = Some part }
    | Yes [] | No | Help | Error -> Ask_again
    | Back -> Prev
  in

  let ask_verify state =
    match
    yesno "Verify and proceed"
      (sprintf "\nPlease verify the settings below and click [OK] to proceed, or the [Back] button to return to a previous step.

Connection:   %s
Remote host:  %s
Remote port:  %s
Directory:    %s
Network:      %s
Send devices: %s
Root (/) dev: %s"
         (match state.transport with
          | Some Server -> "Server"
          | Some SSH -> "SSH" | Some TCP -> "TCP socket"
          | None -> "")
         (Option.default "" state.remote_host)
         (Option.default "" state.remote_port)
         (Option.default "" state.remote_directory)
         (match state.network with
          | Some Auto -> "Auto-configure" | Some Shell -> "Shell"
          | None -> "")
         (String.concat "," (Option.default [] state.devices_to_send))
         (Option.map_default dev_of_partition "" state.root_filesystem))
      18 50
    with
    | Yes _ -> Next state
    | Back -> Prev
    | No | Help | Error -> Ask_again
  in

  (* This is the list of dialogs, in order.  The user can go forwards or
   * backwards through them.  The second parameter in each pair is
   * false if we need to skip this dialog (info already supplied in
   * 'defaults' above).
   *)
  let dlgs = [|
    ask_greeting,                       (* Initial greeting. *)
      defaults.greeting;
    ask_transport,                      (* Transport (ssh, tcp) *)
      defaults.transport = None;
    ask_hostname,                       (* Hostname. *)
      defaults.remote_host = None;
    ask_port,                           (* Port number. *)
      defaults.remote_port = None;
    ask_directory,                      (* Remote directory. *)
      defaults.remote_directory = None;
    ask_network,                        (* Network configuration. *)
      defaults.network = None;
    ask_devices,                        (* Block devices to send. *)
      defaults.devices_to_send = None;
    ask_root,                           (* Root filesystem. *)
      defaults.root_filesystem = None;
    ask_verify,                         (* Verify settings. *)
      defaults.greeting
  |] in

  (* Loop through the dialogs until we reach the end. *)
  let rec loop posn state =
    eprintf "dialog loop: posn = %d\n%!" posn;
    if posn >= Array.length dlgs then state (* Finished all dialogs. *)
    else (
      let dlg, no_skip = dlgs.(posn) in
      let skip = not no_skip in
      if skip then
        (* Skip this dialog and move straight to the next one. *)
        loop (posn+1) state
      else (
        (* Run dialog. *)
        match dlg state with
        | Next new_state -> loop (posn+1) new_state (* Forwards. *)
        | Prev -> loop (posn-1) state       (* Backwards / back button. *)
        | Ask_again -> loop posn state      (* Repeat the question. *)
      )
    )
  in
  let state = loop 0 defaults in

  eprintf "finished dialog loop\nfinal state = %s\n%!" (string_of_state state);

  (* Check that the environment is a sane-looking live CD.  If not, bail. *)
  if is_dir "/mnt/root" <> Some true then
    fail_dialog "You should only run this script from the live CD or a USB key.";

  (* Switch LVM config. *)
  sh "vgchange -a n";
  putenv "LVM_SYSTEM_DIR" "/etc/lvm.new"; (* see lvm(8) *)
  sh "rm -f /etc/lvm/cache/.cache";
  sh "rm -f /etc/lvm.new/cache/.cache";

  (* Snapshot the block devices to send. *)
  let devices_to_send = Option.get state.devices_to_send in
  let devices_to_send =
    List.map (
      fun origin_dev ->
        let snapshot_dev = snapshot_name origin_dev in
        snapshot origin_dev snapshot_dev;
        (origin_dev, snapshot_dev)
    ) devices_to_send in

  (* Run kpartx on the snapshots. *)
  List.iter (
    fun (origin, snapshot) ->
      shfailok ("kpartx -a " ^ quote ("/dev/mapper/" ^ snapshot))
  ) devices_to_send;

  (* Rescan for LVs. *)
  sh "vgscan";
  sh "vgchange -a y";

  (* Mount the root filesystem under /mnt/root. *)
  let root_filesystem = Option.get state.root_filesystem in
  (match root_filesystem with
   | Part (dev, partnum) ->
       let dev = dev ^ partnum in
       let snapshot_dev = snapshot_name dev in
       sh ("mount " ^ quote ("/dev/mapper/" ^ snapshot_dev) ^ " /mnt/root")

   | LV (vg, lv) ->
       (* The LV will be backed by a snapshot device, so just mount
        * directly.
        *)
       sh ("mount " ^ quote ("/dev/" ^ vg ^ "/" ^ lv) ^ " /mnt/root")
  );

  (* See if we can do network configuration. *)
  let network = Option.get state.network in
  (match network with
   | Shell ->
       printf "Network configuration.\n\n";
       printf "Please configure the network from this shell.\n\n";
       printf "When you have finished, exit the shell with ^D or exit.\n\n%!";
       shell ()

   | Auto ->
       printf
         "Trying network auto-configuration from root filesystem ...\n\n%!";
       if not (auto_network state) then (
         printf "\nAuto-configuration failed.  Starting a shell.\n\n";
         printf "Please configure the network from this shell.\n\n";
         printf "When you have finished, exit the shell with ^D or exit.\n\n";
         shell ()
       )
  );

  (* Work out what devices will be called at the remote end. *)
  let devices_to_send = List.map (
    fun (origin_dev, snapshot_dev) ->
      let remote_dev = remote_of_origin_dev origin_dev in
      (origin_dev, snapshot_dev, remote_dev)
  ) devices_to_send in

  (* Modify files on the root filesystem. *)
  rewrite_fstab state devices_to_send;
  (* XXX Other files to rewrite? *)

  (* Unmount the root filesystem and sync disks. *)
  sh "umount /mnt/root";
  sh "sync";                            (* Ugh, should be in stdlib. *)

  (* Disable screen blanking on console. *)
  sh "setterm -blank 0";

  (* For Server and TCP type connections, we connect just once. *)
  let remote_host = Option.get state.remote_host in
  let remote_port = Option.get state.remote_port in
  let remote_directory = Option.get state.remote_directory in
  let transport = Option.get state.transport in

  let sock =
    match transport with
    | Server | TCP ->
      let addrs =
        getaddrinfo remote_host remote_port [AI_SOCKTYPE SOCK_STREAM] in
      let rec loop = function
        | [] ->
            fail_dialog
              (sprintf "Unable to connect to %s:%s" remote_host remote_port)
        | addr :: addrs ->
            try
              let sock =
                socket addr.ai_family addr.ai_socktype addr.ai_protocol in
              connect sock addr.ai_addr;
              sock
            with Unix_error (err, syscall, extra) ->
              (* Log the error message, but continue around the loop. *)
              eprintf "%s:%s: %s\n%!" syscall extra (error_message err);
              loop addrs
      in
      loop addrs
    | SSH ->
        (* Just dummy socket for SSH for now ... *) stdin in

  (* Send the device snapshots to the remote host. *)
  (* XXX This is using the hostname derived from network configuration
   * above.  We might want to ask the user to choose.
   *)
  let basename =
    let hostname = safe_name (gethostname ()) in
    let date = sprintf "%04d%02d%02d%02d%02d"
      (tm.tm_year+1900) (tm.tm_mon+1) tm.tm_mday tm.tm_hour tm.tm_min in
    "p2v-" ^ hostname ^ "-" ^ date in

  (* XXX This code should be made more robust against both network
   * errors and local I/O errors.  Also should allow the user several
   * attempts to connect, or let them go back to the dialog stage.
   *)
  List.iter (
    fun (origin_dev, snapshot_dev, remote_dev) ->
      let remote_name = basename ^ "-" ^ remote_dev ^ ".img" in
      eprintf "sending %s as %s\n%!" origin_dev remote_name;

      let size =
        try List.assoc origin_dev all_block_devices
        with Not_found -> assert false (* internal error *) in

      printf "Sending /dev/%s (%.3f GB) to remote machine\n%!" origin_dev
        ((Int64.to_float size) /. (1024.*.1024.*.1024.));

      (* Open the snapshot device. *)
      let fd = openfile ("/dev/mapper/" ^ snapshot_dev) [O_RDONLY] 0 in

      (* Now connect (for SSH) or send the header (for Server/TCP). *)
      let sock, chan =
        match transport with
        | Server | TCP ->
            let header = sprintf "p2v2 %s %Ld\n%!" remote_name size in
            let len = String.length header in
            assert (len = write sock header 0 len);
            sock, Pervasives.stdout
        | SSH ->
            let cmd = sprintf "ssh -C -p %s %s \"cat > %s/%s\""
              (quote remote_port) (quote remote_host)
              (quote remote_directory) (quote remote_name) in
            let chan = open_process_out cmd in
            let fd = descr_of_out_channel chan in
            fd, chan in

      (* Copy the data. *)
      let bufsize = 1024 * 1024 in
      let buffer = String.create bufsize in
      let start = gettimeofday () in

      let rec copy bytes_sent last_printed_at =
        let n = read fd buffer 0 bufsize in
        if n > 0 then (
          ignore (write sock buffer 0 n);

          let bytes_sent = Int64.add bytes_sent (Int64.of_int n) in
          let last_printed_at =
            let now = gettimeofday () in
            (* Print progress once per second. *)
            if now -. last_printed_at > 1. then (
              let elapsed = Int64.to_float bytes_sent /. Int64.to_float size in
              let secs_elapsed = now -. start in
              printf "%.0f%%" (100. *. elapsed);
              (* After 60 seconds has elapsed, start printing estimates. *)
              if secs_elapsed >= 60. then (
                let remaining = 1. -. elapsed in
                let secs_remaining = (remaining /. elapsed) *. secs_elapsed in
                if secs_remaining > 120. then
                  printf " (about %.0f minutes remaining)          "
                    (secs_remaining /. 60.)
                else
                  printf " (about %.0f seconds remaining)          "
                    secs_remaining
              );
              printf "\r%!";
              now
            )
            else last_printed_at in

          copy bytes_sent last_printed_at
        )
      in
      copy 0L start;

      (* For SSH disconnect, for Server/TCP send a newline. *)
      match transport with
      | Server | TCP ->
          ignore (write sock "\n" 0 1)
      | SSH ->
          match close_process_out chan with
          | WEXITED 0 -> ()             (* OK *)
          | WEXITED i -> failwith (sprintf "ssh: exited with error code %d" i)
          | WSIGNALED i -> failwith (sprintf "ssh: killed by signal %d" i)
          | WSTOPPED i -> failwith (sprintf "ssh: stopped by signal %d" i)
  ) devices_to_send;

  (* Disconnect. *)
  (match transport with
   | Server | TCP -> close sock
   | SSH -> ()
  );

  (* XXX Write a configuration file. *)
  let conf_filename = basename ^ ".conf" in

  (* Clean up and reboot. *)
  ignore (
    msgbox "virt-p2v completed"
      (sprintf "\nThe physical to virtual migration is complete.\n\nPlease verify the disk image(s) and configuration file on the remote host, and then start up the virtual machine by doing:\n\nvirsh define %s/%s\n\nWhen you press [OK] this machine will reboot."
         (Option.default "" state.remote_directory) conf_filename)
      17 50
  );

  shfailok "eject";
  shfailok "reboot";
  exit 0

let usage () =
  eprintf "usage: virt-p2v [ttyname]\n%!";
  exit 2

(* Make sure that exceptions from 'main' get printed out on stdout
 * as well as stderr, since stderr is probably redirected to the
 * logfile, and so not visible to the user.
 *)
let handle_exn f arg =
  try f arg
  with exn -> print_endline (Printexc.to_string exn); raise exn

(* If the ISO image has an attachment then it could be a new version
 * of virt-p2v.ml (this script).  Get the attachment and run it
 * instead.  Useful mainly for testing, in conjunction with the
 * 'make update' target in the virt-p2v Makefile.
 *)
let magic = "ISOATTACHMENT002"
let magiclen = String.length magic  (* = 16 bytes *)
let trailerlen = magiclen + 8 + 8   (* magic + file start + true size *)

let int64_of_string str =
  let i = ref 0L in
  let add offs shift =
    i :=
      Int64.logor
        (Int64.shift_left (Int64.of_int (Char.code str.[offs])) shift) !i
  in
  add 0 56;  add 1 48;  add 2 40;  add 3 32;
  add 4 24;  add 5 16;  add 6 8;   add 7 0;
  !i

let update ttyname =
  let cdrom = "/dev/cdrom" in
  let output = "/tmp/virt-p2v.ml" in

  try
    let fd = openfile cdrom [O_RDONLY] 0 in
    ignore (LargeFile.lseek fd (Int64.of_int ~-trailerlen) SEEK_END);
    let buf = String.create magiclen in
    if read fd buf 0 magiclen <> magiclen || buf <> magic then (
      close fd;
      raise Exit
    );

    (* Read the size. *)
    let buf = String.create 8 in
    if read fd buf 0 8 <> 8 then
      failwith "cannot read attachment offset";
    let offset = int64_of_string buf in
    let buf = String.create 8 in
    if read fd buf 0 8 <> 8 then
      failwith "cannot read attachment size";
    let size = Int64.to_int (int64_of_string buf) in

    (* Seek to beginning of the attachment. *)
    ignore (LargeFile.lseek fd offset SEEK_SET);

    (* Copy out the attachment. *)
    let fd2 = openfile output [O_WRONLY; O_CREAT; O_TRUNC] 0o755 in
    let bufsize = 4 * 1024 in
    let buffer = String.create bufsize in
    let rec copy remaining =
      if remaining > 0 then (
        let n = min remaining bufsize in
        let n = read fd buffer 0 n in
        if n = 0 then failwith "corrupted or partial attachment";
        ignore (write fd2 buffer 0 n);
        copy (remaining - n)
      )
    in
    copy size;
    close fd2;

    close fd;

    (* Run updated virt-p2v script. *)
    execv output [| output; ttyname |]
  with
    Unix_error _ | Exit ->
      (* Some error, or no attachment, so keep running this script. *)
      handle_exn main (Some ttyname)

(* Test harness for the Makefile.  The Makefile invokes this script as
 * 'virt-p2v.ml --test' just to check it compiles.  When it is running
 * from the actual live CD, there is a single parameter which is the
 * tty name (so usually 'virt-p2v.ml tty1').
 *)
let () =
  match Array.to_list Sys.argv with
  | [ _; "--test" ] -> ()               (* Makefile test - do nothing. *)
  | [ _; "--update"; ttyname ] ->       (* Test for update and run. *)
      update ttyname
  | [ _; ("--help"|"-help"|"-?"|"-h") ] -> usage ();
  | [ _; ttyname ] ->                   (* Run main with ttyname. *)
      handle_exn main (Some ttyname)
  | [ _ ] ->                            (* Interactive - no ttyname. *)
      handle_exn main None
  | _ -> usage ()

(* This file must end with a newline *)