Can detect malformed ddrescue files where the disk map is not contigu…

…ous or is overlapping

src/error.rs

@@ -5,6 +5,7 @@ use std::io::Write;
 use std::{env, io::ErrorKind, process};
 use termcolor::{self, Color, ColorChoice, ColorSpec, StandardStream, WriteColor};
 
+/// Represents all the exit codes of the program with 0 being success and the rest being errors
 #[repr(i32)]
 pub enum ExitCode {
     FileError = 1,
@@ -15,7 +16,6 @@ pub enum ExitCode {
     OOMError = 6,
     ParseError = 7,
     UnmountError = 8,
-    /// Sector Size not a multiple of 512
     SectorSizeError = 9,
     UnknownError = 10,
 }
@@ -44,6 +44,12 @@ pub const NO_DEVICE_UNMOUNT_ERROR: &str = "Unmount error: Unable to find device"
 pub const UNMOUNT_ERROR: &str = "Unable to unmount device";
 pub const FILE_NOT_FOUND_ERROR: &str = "Unable to find";
 pub const SECTOR_SIZE_ERROR: &str = "Sector size is not a multiple of 512";
+pub const CONTIGUOUS_ERROR: &str = "ddrescue map of disk is not contiguous";
+
+pub fn contiguous_error() -> ! {
+    print_error(CONTIGUOUS_ERROR);
+    process::exit(ExitCode::ParseError as i32);
+}
 
 pub fn file_not_found(filetype: FileType) -> String {
     format!("{FILE_NOT_FOUND_ERROR} {}", filetype.to_string())

src/parser.rs

@@ -2,6 +2,7 @@ use crate::error;
 use std::{ffi::OsString, fmt::Write, fs};
 
 /// Parses ddrescue map file to dmsetup table
+/// Structure of map file can be found [here](https://www.gnu.org/software/ddrescue/manual/ddrescue_manual.html#Mapfile-structure)
 pub fn parse_map(map_path: &OsString, device_name: &str) -> String {
     let mut output = String::new();
     let contents = fs::read_to_string(map_path.clone()).unwrap_or_else(|error| {
@@ -18,6 +19,8 @@ pub fn parse_map(map_path: &OsString, device_name: &str) -> String {
         .filter(|s| !s.is_empty() && !s.contains('#'))
         .skip(1);
 
+    let mut prev_entry = 0;
+
     for line in file_line {
         let mut map_line = line.split_ascii_whitespace();
         let pos_string = map_line.next().expect(error::PARSE_ERROR).to_string();
@@ -41,6 +44,13 @@ pub fn parse_map(map_path: &OsString, device_name: &str) -> String {
         } else {
             error::handle_string_write(writeln!(output, "{}", create_error(pos, size)));
         }
+
+        // Check if sector is contiguous
+        if pos != prev_entry {
+            error::contiguous_error();
+        } else {
+            prev_entry = pos + size;
+        }
     }
 
     output