Add the --progress option to the fill command

The fill command starts a background operation on a Nitrokey Storage
device that fills the SD card with random data.  This patch adds a new
option, --progress, to the fill command that checks if a fill operation
is already running on the device and shows its progress.

doc/nitrocli.1

@@ -137,7 +137,7 @@ open.
 \fBnitrocli hidden close
 Close a hidden volume.
 .TP
-\fBnitrocli fill\fR
+\fBnitrocli fill \fR[\fB\-a\fR|\fB\-\-attach\fR
 Fills the SD card with random data, overwriting all existing data.
 This operation takes about one hour to finish for a 16 GiB SD card.
 It cannot be canceled, even if the \fBnitrocli\fR process is terminated before
@@ -147,6 +147,11 @@ This command requires the admin PIN.
 To avoid accidental calls of this command, the user has to enter the PIN even
 if it has been cached.
 
+If the \fB\-\-attach\fR option is set, this command will not start a new fill
+operation.
+Instead it checks whether a fill operation is currently running on the device
+and shows its progress.
+
 .SS One-time passwords
 The Nitrokey Pro and the Nitrokey Storage support the generation of one-time
 passwords using the HOTP algorithm according to RFC 4226 or the TOTP algorithm

src/args.rs

@@ -80,7 +80,7 @@ Command! {
  /// Interacts with the device's encrypted volume
  Encrypted(EncryptedArgs) => |ctx, args: EncryptedArgs| args.subcmd.execute(ctx),
  /// Fills the SD card with random data
- Fill => crate::commands::fill,
+ Fill(FillArgs) => |ctx, args: FillArgs| crate::commands::fill(ctx, args.attach),
  /// Interacts with the device's hidden volume
  Hidden(HiddenArgs) => |ctx, args: HiddenArgs| args.subcmd.execute(ctx),
  /// Lists the attached Nitrokey devices
@@ -189,6 +189,14 @@ Command! {EncryptedCommand, [
  Open => crate::commands::encrypted_open,
 ]}
 
+#[derive(Debug, PartialEq, structopt::StructOpt)]
+pub struct FillArgs {
+ /// Checks if a fill operation is already running and show its progress instead of starting a new
+ /// operation.
+ #[structopt(short, long)]
+ attach: bool,
+}
+
 #[derive(Debug, PartialEq, structopt::StructOpt)]
 pub struct HiddenArgs {
  #[structopt(subcommand)]

src/commands.rs

@@ -471,19 +471,30 @@ pub fn list(ctx: &mut Context<'_>, no_connect: bool) -> anyhow::Result<()> {
 }
 
 /// Fill the SD card with random data
-pub fn fill(ctx: &mut Context<'_>) -> anyhow::Result<()> {
+pub fn fill(ctx: &mut Context<'_>, attach: bool) -> anyhow::Result<()> {
  with_storage_device(ctx, |ctx, mut device| {
- let pin_entry = pinentry::PinEntry::from(args::PinType::Admin, &device)?;
+ let mut initial_progress = 0;
+ if attach {
+ let status = device
+ .get_operation_status()
+ .context("Failed to query operation status")?;
+ match status {
+ nitrokey::OperationStatus::Ongoing(progress) => initial_progress = progress,
+ nitrokey::OperationStatus::Idle => anyhow::bail!("No fill operation in progress"),
+ }
+ } else {
+ let pin_entry = pinentry::PinEntry::from(args::PinType::Admin, &device)?;
 
- // Similar to reset, we want the user to re-enter the admin PIN even if is cached to avoid
- // accidental data loss.
- pinentry::clear(&pin_entry).context("Failed to clear cached secret")?;
+  // Similar to reset, we want the user to re-enter the admin PIN
+  // even if is cached to avoid accidental data loss.
+  pinentry::clear(&pin_entry).context("Failed to clear cached secret")?;
 
- try_with_pin(ctx, &pin_entry, |pin| {
- device.fill_sd_card(&pin).context("Failed to fill SD card")
- })?;
+ try_with_pin(ctx, &pin_entry, |pin| {
+ device.fill_sd_card(&pin).context("Failed to fill SD card")
+ })?;
+ }
 
- let mut progress_bar = output::ProgressBar::new();
+ let mut progress_bar = output::ProgressBar::new(initial_progress);
  progress_bar.draw(ctx)?;
 
  while !progress_bar.is_finished() {

src/output.rs

@@ -26,10 +26,10 @@ pub struct ProgressBar {
 
 impl ProgressBar {
  /// Creates a new empty progress bar.
- pub fn new() -> ProgressBar {
+ pub fn new(progress: u8) -> ProgressBar {
  ProgressBar {
  redraw: true,
- progress: 0,
+ progress,
  toggle: false,
  finished: false,
  }