add chunk inspection to pb-debug

Adds possibility to inspect chunks and find indexes that reference the
chunk. Options:
 - chunk: path to the chunk file
 - [opt] decode: path to a file or to stdout(-), if specified, the
   chunk will be decoded into the specified location
 - [opt] digest: needed when searching for references, if set, it will
   be used for verification when decoding
 - [opt] keyfile: path to a keyfile, needed if decode is specified and
   the data was encrypted
 - [opt] reference-filter: path in which indexes that reference the
   chunk should be searched, can be a group, snapshot or the whole
   datastore, if not specified no references will be searched
 - [default=true] use-filename-as-digest: use chunk-filename as digest,
   if no digest is specified

Signed-off-by: Hannes Laimer <h.laimer@proxmox.com>
Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>

Makefile

@@ -17,7 +17,8 @@ USR_BIN := \
 
 # Binaries usable by admins
 USR_SBIN := \
-	proxmox-backup-manager
+	proxmox-backup-manager \
+	proxmox-backup-debug \
 
 # Binaries for services:
 SERVICE_BIN := \

src/bin/proxmox-backup-debug.rs

@@ -0,0 +1,13 @@
+use proxmox::api::cli::*;
+
+mod proxmox_backup_debug;
+use proxmox_backup_debug::inspect_commands;
+
+fn main() {
+    proxmox_backup::tools::setup_safe_path_env();
+
+    let cmd_def = CliCommandMap::new().insert("inspect", inspect_commands());
+
+    let rpcenv = CliEnvironment::new();
+    run_cli_command(cmd_def, rpcenv, Some(|future| pbs_runtime::main(future)));
+}

src/bin/proxmox_backup_debug/inspect.rs

@@ -0,0 +1,213 @@
+use std::path::Path;
+
+use anyhow::{format_err, Error};
+use proxmox::api::cli::{
+    format_and_print_result, get_output_format, CliCommand, CliCommandMap, CommandLineInterface,
+};
+use proxmox::api::{api, cli::*};
+use serde_json::{json, Value};
+use walkdir::WalkDir;
+
+use proxmox_backup::backup::{
+    load_and_decrypt_key, CryptConfig, DataBlob, DynamicIndexReader, FixedIndexReader, IndexFile,
+};
+
+use pbs_client::tools::key_source::get_encryption_key_password;
+
+use proxmox_backup::tools::outfile_or_stdout;
+
+/// Decodes a blob and writes its content either to stdout or into a file
+fn decode_blob(
+    mut output_path: Option<&Path>,
+    key_file: Option<&Path>,
+    digest: Option<&[u8; 32]>,
+    blob: &DataBlob,
+) -> Result<(), Error> {
+    let mut crypt_conf_opt = None;
+    let crypt_conf;
+
+    if blob.is_encrypted() && key_file.is_some() {
+        let (key, _created, _fingerprint) =
+            load_and_decrypt_key(&key_file.unwrap(), &get_encryption_key_password)?;
+        crypt_conf = CryptConfig::new(key)?;
+        crypt_conf_opt = Some(&crypt_conf);
+    }
+
+    output_path = match output_path {
+        Some(path) if path.eq(Path::new("-")) => None,
+        _ => output_path,
+    };
+
+    outfile_or_stdout(output_path)?.write_all(blob.decode(crypt_conf_opt, digest)?.as_slice())?;
+    Ok(())
+}
+
+#[api(
+    input: {
+        properties: {
+            chunk: {
+                description: "The chunk file.",
+                type: String,
+            },
+            "reference-filter": {
+                description: "Path to the directory that should be searched for references.",
+                type: String,
+                optional: true,
+            },
+            "digest": {
+                description: "Needed when searching for references, if set, it will be used for verification when decoding.",
+                type: String,
+                optional: true,
+            },
+            "decode": {
+                description: "Path to the file to which the chunk should be decoded, '-' -> decode to stdout.",
+                type: String,
+                optional: true,
+            },
+            "keyfile": {
+                description: "Path to the keyfile with which the chunk was encrypted.",
+                type: String,
+                optional: true,
+            },
+            "use-filename-as-digest": {
+                description: "The filename should be used as digest for reference search and decode verification, if no digest is specified.",
+                type: bool,
+                optional: true,
+                default: true,
+            },
+            "output-format": {
+                schema: OUTPUT_FORMAT,
+                optional: true,
+            },
+        }
+    }
+)]
+/// Inspect a chunk
+fn inspect_chunk(
+    chunk: String,
+    reference_filter: Option<String>,
+    mut digest: Option<String>,
+    decode: Option<String>,
+    keyfile: Option<String>,
+    use_filename_as_digest: bool,
+    param: Value,
+) -> Result<(), Error> {
+    let output_format = get_output_format(&param);
+    let chunk_path = Path::new(&chunk);
+
+    if digest.is_none() && use_filename_as_digest {
+        digest = Some(if let Some((_, filename)) = chunk.rsplit_once("/") {
+            String::from(filename)
+        } else {
+            chunk.clone()
+        });
+    };
+
+    let digest_raw: Option<[u8; 32]> = digest
+        .map(|ref d| {
+            proxmox::tools::hex_to_digest(d)
+                .map_err(|e| format_err!("could not parse chunk - {}", e))
+        })
+        .map_or(Ok(None), |r| r.map(Some))?;
+
+    let search_path = reference_filter.as_ref().map(Path::new);
+    let key_file_path = keyfile.as_ref().map(Path::new);
+    let decode_output_path = decode.as_ref().map(Path::new);
+
+    let blob = DataBlob::load_from_reader(
+        &mut std::fs::File::open(&chunk_path)
+            .map_err(|e| format_err!("could not open chunk file - {}", e))?,
+    )?;
+
+    let referenced_by = if let (Some(search_path), Some(digest_raw)) = (search_path, digest_raw) {
+        let mut references = Vec::new();
+        for entry in WalkDir::new(search_path)
+            .follow_links(false)
+            .into_iter()
+            .filter_map(|e| e.ok())
+        {
+            use std::os::unix::ffi::OsStrExt;
+            let file_name = entry.file_name().as_bytes();
+
+            let index: Box<dyn IndexFile> = if file_name.ends_with(b".fidx") {
+                match FixedIndexReader::open(entry.path()) {
+                    Ok(index) => Box::new(index),
+                    Err(_) => continue,
+                }
+            } else if file_name.ends_with(b".didx") {
+                match DynamicIndexReader::open(entry.path()) {
+                    Ok(index) => Box::new(index),
+                    Err(_) => continue,
+                }
+            } else {
+                continue;
+            };
+
+            for pos in 0..index.index_count() {
+                if let Some(index_chunk_digest) = index.index_digest(pos) {
+                    if digest_raw.eq(index_chunk_digest) {
+                        references.push(entry.path().to_string_lossy().into_owned());
+                        break;
+                    }
+                }
+            }
+        }
+        if !references.is_empty() {
+            Some(references)
+        } else {
+            None
+        }
+    } else {
+        None
+    };
+
+    if decode_output_path.is_some() {
+        decode_blob(
+            decode_output_path,
+            key_file_path,
+            digest_raw.as_ref(),
+            &blob,
+        )?;
+    }
+
+    let crc_status = format!(
+        "{}({})",
+        blob.compute_crc(),
+        blob.verify_crc().map_or("BAD", |_| "OK")
+    );
+
+    let val = match referenced_by {
+        Some(references) => json!({
+            "crc": crc_status,
+            "encryption": blob.crypt_mode()?,
+            "referenced-by": references
+        }),
+        None => json!({
+             "crc": crc_status,
+             "encryption": blob.crypt_mode()?,
+        }),
+    };
+
+    if output_format == "text" {
+        println!("CRC: {}", val["crc"]);
+        println!("encryption: {}", val["encryption"]);
+        if let Some(refs) = val["referenced-by"].as_array() {
+            println!("referenced by:");
+            for reference in refs {
+                println!("  {}", reference);
+            }
+        }
+    } else {
+        format_and_print_result(&val, &output_format);
+    }
+    Ok(())
+}
+
+pub fn inspect_commands() -> CommandLineInterface {
+    let cmd_def = CliCommandMap::new().insert(
+        "chunk",
+        CliCommand::new(&API_METHOD_INSPECT_CHUNK).arg_param(&["chunk"]),
+    );
+
+    cmd_def.into()
+}

src/bin/proxmox_backup_debug/mod.rs

@@ -0,0 +1,2 @@
+mod inspect;
+pub use inspect::*;

src/tools/mod.rs

@@ -2,7 +2,10 @@
 //!
 //! This is a collection of small and useful tools.
 use std::any::Any;
+use std::fs::File;
+use std::io::{stdout, Write};
 use std::os::unix::io::RawFd;
+use std::path::Path;
 
 use anyhow::{bail, format_err, Error};
 use openssl::hash::{hash, DigestBytes, MessageDigest};
@@ -224,3 +227,13 @@ pub fn create_run_dir() -> Result<(), Error> {
     let _: bool = create_path(pbs_buildcfg::PROXMOX_BACKUP_RUN_DIR_M!(), None, Some(opts))?;
     Ok(())
 }
+
+/// Returns either a new file, if a path is given, or stdout, if no path is given.
+pub fn outfile_or_stdout<P: AsRef<Path>>(path: Option<P>) -> Result<Box<dyn Write>, Error> {
+    if let Some(path) = path {
+        let f = File::create(path)?;
+        Ok(Box::new(f) as Box<dyn Write>)
+    } else {
+        Ok(Box::new(stdout()) as Box<dyn Write>)
+    }
+}