file-restore(-daemon): implement list API

Allows listing files and directories on a block device snapshot.
Hierarchy displayed is:

/archive.img.fidx/bucket/component/<path>
e.g.
/drive-scsi0.img.fidx/part/2/etc/passwd
(corresponding to /etc/passwd on the second partition of drive-scsi0)

Signed-off-by: Stefan Reiter <s.reiter@proxmox.com>
Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>

src/bin/proxmox_file_restore/block_driver.rs

@@ -9,6 +9,7 @@ use std::hash::BuildHasher;
 use std::pin::Pin;
 
 use proxmox_backup::backup::{BackupDir, BackupManifest};
+use proxmox_backup::api2::types::ArchiveEntry;
 use proxmox_backup::client::BackupRepository;
 
 use proxmox::api::{api, cli::*};
@@ -32,6 +33,14 @@ pub type Async<R> = Pin<Box<dyn Future<Output = R> + Send>>;
 
 /// An abstract implementation for retrieving data out of a block file backup
 pub trait BlockRestoreDriver {
+    /// List ArchiveEntrys for the given image file and path
+    fn data_list(
+        &self,
+        details: SnapRestoreDetails,
+        img_file: String,
+        path: Vec<u8>,
+    ) -> Async<Result<Vec<ArchiveEntry>, Error>>;
+
     /// Return status of all running/mapped images, result value is (id, extra data), where id must
     /// match with the ones returned from list()
     fn status(&self) -> Async<Result<Vec<DriverStatus>, Error>>;
@@ -60,6 +69,16 @@ impl BlockDriverType {
 const DEFAULT_DRIVER: BlockDriverType = BlockDriverType::Qemu;
 const ALL_DRIVERS: &[BlockDriverType] = &[BlockDriverType::Qemu];
 
+pub async fn data_list(
+    driver: Option<BlockDriverType>,
+    details: SnapRestoreDetails,
+    img_file: String,
+    path: Vec<u8>,
+) -> Result<Vec<ArchiveEntry>, Error> {
+    let driver = driver.unwrap_or(DEFAULT_DRIVER).resolve();
+    driver.data_list(details, img_file, path).await
+}
+
 #[api(
    input: {
        properties: {

src/bin/proxmox_file_restore/block_driver_qemu.rs

@@ -9,6 +9,7 @@ use std::fs::{File, OpenOptions};
 use std::io::{prelude::*, SeekFrom};
 
 use proxmox::tools::fs::lock_file;
+use proxmox_backup::api2::types::ArchiveEntry;
 use proxmox_backup::backup::BackupDir;
 use proxmox_backup::client::*;
 use proxmox_backup::tools;
@@ -183,6 +184,26 @@ async fn start_vm(cid_request: i32, details: &SnapRestoreDetails) -> Result<VMSt
 }
 
 impl BlockRestoreDriver for QemuBlockDriver {
+    fn data_list(
+        &self,
+        details: SnapRestoreDetails,
+        img_file: String,
+        mut path: Vec<u8>,
+    ) -> Async<Result<Vec<ArchiveEntry>, Error>> {
+        async move {
+            let client = ensure_running(&details).await?;
+            if !path.is_empty() && path[0] != b'/' {
+                path.insert(0, b'/');
+            }
+            let path = base64::encode(img_file.bytes().chain(path).collect::<Vec<u8>>());
+            let mut result = client
+                .get("api2/json/list", Some(json!({ "path": path })))
+                .await?;
+            serde_json::from_value(result["data"].take()).map_err(|err| err.into())
+        }
+        .boxed()
+    }
+
     fn status(&self) -> Async<Result<Vec<DriverStatus>, Error>> {
         async move {
             let mut state_map = VMStateMap::load()?;