[pbs-devel] [PATCH v3 proxmox-backup 3/3] add index recovery to pb-debug

[Hannes Laimer]

Adds possibility to recover data from an index file. Options:
 - chunks: path to the directory where the chunks are saved
 - file: the index file that should be recovered(must be either .fidx or
   didx)
 - [opt] keyfile: path to a keyfile, if the data was encrypted, a keyfile is
   needed
 - [opt] skip-crc: boolean, if true, read chunks wont be verified with their
   crc-sum, increases the restore speed by a lot

Signed-off-by: Hannes Laimer <h.laimer at proxmox.com>
---

 src/bin/proxmox-backup-debug.rs         |   6 +-
 src/bin/proxmox_backup_debug/mod.rs     |   2 +
 src/bin/proxmox_backup_debug/recover.rs | 109 ++++++++++++++++++++++++
 3 files changed, 115 insertions(+), 2 deletions(-)
 create mode 100644 src/bin/proxmox_backup_debug/recover.rs

diff --git a/src/bin/proxmox-backup-debug.rs b/src/bin/proxmox-backup-debug.rs
index 079b2bc8..8bd01a59 100644
--- a/src/bin/proxmox-backup-debug.rs
+++ b/src/bin/proxmox-backup-debug.rs
@@ -22,7 +22,9 @@ pub const KEYFILE_SCHEMA: Schema = StringSchema::new(
 fn main() {
     proxmox_backup::tools::setup_safe_path_env();
 
-    let cmd_def = CliCommandMap::new().insert("inspect", inspect_commands());
+    let cmd_def = CliCommandMap::new()
+        .insert("inspect", inspect_commands())
+        .insert("recover", recover_commands());
 
     let rpcenv = CliEnvironment::new();
     run_cli_command(
@@ -30,4 +32,4 @@ fn main() {
         rpcenv,
         Some(|future| proxmox_backup::tools::runtime::main(future)),
     );
-}
+}
\ No newline at end of file
diff --git a/src/bin/proxmox_backup_debug/mod.rs b/src/bin/proxmox_backup_debug/mod.rs
index 644583db..62df7754 100644
--- a/src/bin/proxmox_backup_debug/mod.rs
+++ b/src/bin/proxmox_backup_debug/mod.rs
@@ -1,2 +1,4 @@
 mod inspect;
 pub use inspect::*;
+mod recover;
+pub use recover::*;
diff --git a/src/bin/proxmox_backup_debug/recover.rs b/src/bin/proxmox_backup_debug/recover.rs
new file mode 100644
index 00000000..61025adf
--- /dev/null
+++ b/src/bin/proxmox_backup_debug/recover.rs
@@ -0,0 +1,109 @@
+use std::fs::File;
+use std::io::{Read, Write};
+use std::path::Path;
+
+use anyhow::{bail, format_err, Error};
+
+use proxmox::api::api;
+use proxmox::api::cli::{CliCommand, CliCommandMap, CommandLineInterface};
+use serde_json::Value;
+
+use proxmox_backup::backup::{
+    load_and_decrypt_key, CryptConfig, DataBlob, DynamicIndexReader, FixedIndexReader, IndexFile,
+};
+use proxmox_backup::tools;
+
+use crate::{get_encryption_key_password, KEYFILE_SCHEMA, PATH_SCHEMA};
+
+use proxmox::tools::digest_to_hex;
+
+use std::time::Instant;
+
+#[api(
+    input: {
+        properties: {
+            file: {
+                schema: PATH_SCHEMA,
+            },
+            chunks: {
+                schema: PATH_SCHEMA,
+            },
+            "keyfile": {
+                schema: KEYFILE_SCHEMA,
+                optional: true,
+            },
+            "skip-crc": {
+                type: Boolean,
+                optional: true,
+                default: false,
+                description: "Skip the crc verification, increases the restore speed immensely",
+            }
+        }
+    }
+)]
+/// Recover a index file
+fn recover_index(skip_crc: bool, param: Value) -> Result<Value, Error> {
+    let start = Instant::now();
+    let file_path = Path::new(tools::required_string_param(&param, "file")?);
+    let chunks_path = Path::new(tools::required_string_param(&param, "chunks")?);
+
+    let key_file_param = param["keyfile"].as_str();
+    let key_file_path = key_file_param.map(|path| Path::new(path));
+
+    let index: Box<dyn IndexFile> = match file_path.extension() {
+        Some(ext) if ext.eq("fidx") => Box::new(
+            FixedIndexReader::open(file_path)
+                .map_err(|e| format_err!("could not read index - {}", e))?,
+        ),
+        Some(ext) if ext.eq("didx") => Box::new(
+            DynamicIndexReader::open(file_path)
+                .map_err(|e| format_err!("could not read index - {}", e))?,
+        ),
+        _ => bail!("index file must either be a .fidx or a .didx file"),
+    };
+
+    let mut crypt_conf_opt = None;
+    let mut crypt_conf;
+
+    let output_filename = file_path.file_stem().unwrap().to_str().unwrap();
+    let output_path = Path::new(output_filename);
+    let mut output_file = File::create(output_path)
+        .map_err(|e| format_err!("could not create output file - {}", e))?;
+
+    for pos in 0..index.index_count() {
+        let chunk_digest = index.index_digest(pos).unwrap();
+        let digest_str = digest_to_hex(chunk_digest);
+        let digest_prefix = &digest_str[0..4];
+        let chunk_path = chunks_path.join(digest_prefix).join(digest_str);
+        let mut chunk_file = std::fs::File::open(&chunk_path)
+            .map_err(|e| format_err!("could not open chunk file - {}", e))?;
+
+        let mut data = Vec::with_capacity(1024 * 1024);
+        chunk_file.read_to_end(&mut data)?;
+        let chunk_blob = DataBlob::from_raw(data)?;
+
+        if !skip_crc {
+            chunk_blob.verify_crc()?;
+        }
+
+        if key_file_path.is_some() && chunk_blob.is_encrypted() && crypt_conf_opt.is_none() {
+            let (key, _created, _fingerprint) =
+                load_and_decrypt_key(&key_file_path.unwrap(), &get_encryption_key_password)?;
+            crypt_conf = CryptConfig::new(key)?;
+            crypt_conf_opt = Some(&crypt_conf);
+        }
+
+        output_file.write_all(
+            chunk_blob
+                .decode(crypt_conf_opt, Some(chunk_digest))?
+                .as_slice(),
+        )?;
+    }
+    println!("{} sec.", start.elapsed().as_secs_f32());
+    Ok(Value::Null)
+}
+
+pub fn recover_commands() -> CommandLineInterface {
+    let cmd_def = CliCommandMap::new().insert("index", CliCommand::new(&API_METHOD_RECOVER_INDEX));
+    cmd_def.into()
+}
-- 
2.20.1