add file inspection to pb-debug

Adds possibility to inspect .blob, .fidx and .didx files. For index
files a list of the chunks referenced will be printed in addition to
some other information. .blob files can be decoded into file or directly
into stdout. Without decode the tool just prints the size and encryption
mode of the blob file. Options:
 - file: path to the file
 - [opt] decode: path to a file or stdout(-), if specidied, the file will be
   decoded into the specified location [only for blob files, no effect
   with index files]
 - [opt] keyfile: path to a keyfile, needed if decode is specified and the
   data was encrypted

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

src/bin/proxmox_backup_debug/inspect.rs

@@ -1,6 +1,9 @@
+use std::collections::HashSet;
+use std::fs::File;
+use std::io::{Read, Seek, SeekFrom};
 use std::path::Path;
 
-use anyhow::{format_err, Error};
+use anyhow::{bail, format_err, Error};
 use proxmox::api::cli::{
     format_and_print_result, get_output_format, CliCommand, CliCommandMap, CommandLineInterface,
 };
@@ -10,6 +13,8 @@ use walkdir::WalkDir;
 
 use proxmox_backup::backup::{
     load_and_decrypt_key, CryptConfig, DataBlob, DynamicIndexReader, FixedIndexReader, IndexFile,
+    COMPRESSED_BLOB_MAGIC_1_0, DYNAMIC_SIZED_CHUNK_INDEX_1_0, ENCRYPTED_BLOB_MAGIC_1_0,
+    ENCR_COMPR_BLOB_MAGIC_1_0, FIXED_SIZED_CHUNK_INDEX_1_0, UNCOMPRESSED_BLOB_MAGIC_1_0,
 };
 
 use pbs_client::tools::key_source::get_encryption_key_password;
@@ -203,11 +208,128 @@ fn inspect_chunk(
     Ok(())
 }
 
+#[api(
+    input: {
+        properties: {
+            file: {
+                description: "Path to the file.",
+                type: String,
+            },
+            "decode": {
+                description: "Path to the file to which the file should be decoded, '-' -> decode to stdout.",
+                type: String,
+                optional: true,
+            },
+            "keyfile": {
+                description: "Path to the keyfile with which the file was encrypted.",
+                type: String,
+                optional: true,
+            },
+            "output-format": {
+                schema: OUTPUT_FORMAT,
+                optional: true,
+            },
+        }
+    }
+)]
+/// Inspect a file, for blob file without decode only the size and encryption mode is printed
+fn inspect_file(
+    file: String,
+    decode: Option<String>,
+    keyfile: Option<String>,
+    param: Value,
+) -> Result<(), Error> {
+    let output_format = get_output_format(&param);
+
+    let mut file = File::open(Path::new(&file))?;
+    let mut magic = [0; 8];
+    file.read_exact(&mut magic)?;
+    file.seek(SeekFrom::Start(0))?;
+    let val = match magic {
+        UNCOMPRESSED_BLOB_MAGIC_1_0
+        | COMPRESSED_BLOB_MAGIC_1_0
+        | ENCRYPTED_BLOB_MAGIC_1_0
+        | ENCR_COMPR_BLOB_MAGIC_1_0 => {
+            let data_blob = DataBlob::load_from_reader(&mut file)?;
+            let key_file_path = keyfile.as_ref().map(Path::new);
+
+            let decode_output_path = decode.as_ref().map(Path::new);
+
+            if decode_output_path.is_some() {
+                decode_blob(decode_output_path, key_file_path, None, &data_blob)?;
+            }
+
+            let crypt_mode = data_blob.crypt_mode()?;
+            json!({
+                "encryption": crypt_mode,
+                "size": data_blob.raw_size(),
+            })
+        }
+        FIXED_SIZED_CHUNK_INDEX_1_0 | DYNAMIC_SIZED_CHUNK_INDEX_1_0 => {
+            let index: Box<dyn IndexFile> = match magic {
+                FIXED_SIZED_CHUNK_INDEX_1_0 => {
+                    Box::new(FixedIndexReader::new(file)?) as Box<dyn IndexFile>
+                }
+                DYNAMIC_SIZED_CHUNK_INDEX_1_0 => {
+                    Box::new(DynamicIndexReader::new(file)?) as Box<dyn IndexFile>
+                }
+                _ => bail!(format_err!("This is technically not possible")),
+            };
+
+            let mut ctime_str = index.index_ctime().to_string();
+            if let Ok(s) = proxmox::tools::time::strftime_local("%c", index.index_ctime()) {
+                ctime_str = s;
+            }
+
+            let mut chunk_digests = HashSet::new();
+
+            for pos in 0..index.index_count() {
+                let digest = index.index_digest(pos).unwrap();
+                chunk_digests.insert(proxmox::tools::digest_to_hex(digest));
+            }
+
+            json!({
+                "size": index.index_size(),
+                "ctime": ctime_str,
+                "chunk-digests": chunk_digests
+            })
+        }
+        _ => bail!(format_err!(
+            "Only .blob, .fidx and .didx files may be inspected"
+        )),
+    };
+
+    if output_format == "text" {
+        println!("size: {}", val["size"]);
+        if let Some(encryption) = val["encryption"].as_str() {
+            println!("encryption: {}", encryption);
+        }
+        if let Some(ctime) = val["ctime"].as_str() {
+            println!("creation time: {}", ctime);
+        }
+        if let Some(chunks) = val["chunk-digests"].as_array() {
+            println!("chunks:");
+            for chunk in chunks {
+                println!("  {}", chunk);
+            }
+        }
+    } 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"]),
-    );
+    let cmd_def = CliCommandMap::new()
+        .insert(
+            "chunk",
+            CliCommand::new(&API_METHOD_INSPECT_CHUNK).arg_param(&["chunk"]),
+        )
+        .insert(
+            "file",
+            CliCommand::new(&API_METHOD_INSPECT_FILE).arg_param(&["file"]),
+        );
 
     cmd_def.into()
 }