Add swaplabel applet

Cargo.lock

@@ -579,6 +579,7 @@ dependencies = [
  "clap_mangen",
  "data-encoding",
  "digest",
+ "lazy_static",
  "libc",
  "md-5",
  "mount",

Cargo.toml

@@ -30,7 +30,8 @@ clap_complete = "4.1"
 clap_complete_nushell = "0.1"
 clap_mangen = "0.2"
 data-encoding = "2.3"
-digest = "0.10.6"
+digest = "0.10"
+lazy_static = "1.4"
 libc = { workspace = true }
 md5 = { version = "0.10", package = "md-5" }
 sc = { workspace = true }

README.md

@@ -17,10 +17,10 @@ worth. Like Busybox it is a multi-call binary which is therefore able to share
 code between applets, making for an overall smaller binary.
 
 ## Provided Commands
+- b2sum
 - base32
 - base64
 - basename
-- bootstrap
 - chgrp
 - chmod
 - chown
@@ -37,6 +37,7 @@ code between applets, making for an overall smaller binary.
 - hostid
 - hostname
 - link
+- ln
 - logname
 - md5sum
 - mkfifo
@@ -57,10 +58,11 @@ code between applets, making for an overall smaller binary.
 - sha256sum
 - sha384sum
 - sha512sum
-- shitbox
 - sleep
+- swaplabel
 - sync
 - true
+- umount
 - unlink
 - wc
 - which
@@ -75,9 +77,8 @@ for the project include:
 - Network servers
 - Kernel module handling utilities
 - Anything requiring suid or sgid bits such as `su` or `sudo`
-The code aims to be portable across **Unix** variants, ie Linux and BSD, but not
-MacOS or Windows. Development occurs on Linux, so if your OS is more exotic then
-YMMV.
+The code is not intended to be portable across different architectures, only
+Linux is supported.
 
 ## Installation
 Building is done using the official Rust toolchain. It is recommended that you
@@ -86,11 +87,16 @@ versions are not supported.
 ```Sh
 cargo build --release
 ```
+This produces three binaries: corebox, hashbox and utilbox. Most of the commands
+ordinarily provided by GNU coreutils are applets of `corebox`, with the exception
+of cryptographic hash related commands which are split out into `hashbox`. Linux
+swpecific commands ordinarily provided by the util-linux package are in `utilbox`.
+
 The `bootstrap` applet provides facility for installing the binary, creating all
 required symlinks and installing some nice to haves such as **Unix man pages**
 and **shell completions** [see below].
 ```Sh
-target/release/shitbox help bootstrap
+target/release/corebox help bootstrap
 ```
 ### Supported shells for completions
 - Bash

utilbox/commands/mod.rs

@@ -4,9 +4,12 @@ mod blkid;
 mod clear;
 mod mount;
 mod mountpoint;
+mod swaplabel;
+mod swapoff;
+mod swapon;
 mod umount;
 mod utilbox;
-///
+
 /// Parses a string into a command to run
 #[must_use]
 #[allow(clippy::box_default)]
@@ -14,10 +17,11 @@ pub fn get(name: &str) -> Option<Box<dyn Cmd>> {
     match name {
         "clear" => Some(Box::new(clear::Clear::default())),
         "mountpoint" => Some(Box::new(mountpoint::Mountpoint::default())),
+        "swaplabel" => Some(Box::new(swaplabel::Swaplabel::default())),
         "umount" => Some(Box::new(umount::Umount::default())),
         "utilbox" => Some(Box::new(utilbox::Utilbox::default())),
         _ => None,
     }
 }
 
-pub static COMMANDS: [&str; 4] = ["clear", "mountpoint", "umount", "utilbox"];
+pub static COMMANDS: [&str; 5] = ["clear", "mountpoint", "swaplabel", "umount", "utilbox"];

utilbox/commands/swaplabel/mod.rs

@@ -0,0 +1,81 @@
+use clap::{Arg, ArgMatches, Command};
+use lazy_static::lazy_static;
+use shitbox::Cmd;
+use std::{
+    error::Error,
+    ffi::CString,
+    fs::OpenOptions,
+    io::{self, Read, Seek, SeekFrom, Write},
+};
+
+const SWAP_MAGIC1: &'static str = "SWAPSPACE2";
+const SWAP_MAGIC2: &'static str = "SWAP_SPACE";
+const SWAP_MAGIC_LENGTH: u64 = 10;
+const SWAP_LABEL_LENGTH: u64 = 16;
+const SWAP_LABEL_OFFSET: u64 = 1024 + 4 + 4 + 4 + 16;
+
+lazy_static! {
+    static ref SWAP_MAGIC_OFFSET: u64 =
+        unsafe { libc::sysconf(libc::_SC_PAGESIZE) as u64 - SWAP_MAGIC_LENGTH };
+}
+
+#[derive(Debug, Default)]
+pub struct Swaplabel;
+
+impl Cmd for Swaplabel {
+    fn cli(&self) -> Command {
+        Command::new("swaplabel")
+            .about("set the label of a swap filesystem")
+            .author("Nathan Fisher")
+            .version(env!("CARGO_PKG_VERSION"))
+            .args([
+                Arg::new("label")
+                    .help("set the label")
+                    .short('L')
+                    .visible_short_alias('l')
+                    .long("label")
+                    .num_args(1)
+                    .required(false),
+                Arg::new("device").num_args(1).required(true),
+            ])
+    }
+
+    fn run(&self, matches: &ArgMatches) -> Result<(), Box<dyn Error>> {
+        let mut opts = OpenOptions::new();
+        let device = matches
+            .get_one::<String>("device")
+            .ok_or(io::Error::new(io::ErrorKind::Other, "no device given"))?;
+        let mut fd = opts.read(true).write(true).open(device)?;
+        fd.seek(SeekFrom::Start(*SWAP_MAGIC_OFFSET))?;
+        let mut magic = [0; SWAP_MAGIC_LENGTH as usize];
+        fd.read_exact(&mut magic)?;
+        let m: String = magic.iter().map(|x| *x as char).collect();
+        if m.as_str() != SWAP_MAGIC1 && m.as_str() != SWAP_MAGIC2 {
+            let msg = format!("{device} is not a swap file or partition");
+            println!("Magic String: {m}");
+            return Err(io::Error::new(io::ErrorKind::Other, msg).into());
+        }
+        fd.seek(SeekFrom::Start(SWAP_LABEL_OFFSET))?;
+        if let Some(label) = matches.get_one::<String>("label") {
+            if label.len() + 1 > SWAP_LABEL_LENGTH as usize {
+                return Err(io::Error::new(io::ErrorKind::Other, "label is too long").into());
+            }
+            let label = CString::new(label.as_str())?;
+            fd.write(label.as_bytes())?;
+        } else {
+            let mut label = [0; SWAP_LABEL_LENGTH as usize];
+            fd.read_exact(&mut label)?;
+            let label: String = label
+                .iter()
+                .map(|x| *x as char)
+                .take_while(|x| *x != '\0')
+                .collect();
+            println!("label: {label}");
+        }
+        Ok(())
+    }
+
+    fn path(&self) -> Option<shitbox::Path> {
+        Some(shitbox::Path::UsrSbin)
+    }
+}

utilbox/commands/swapoff/mod.rs

@@ -0,0 +1 @@
+

utilbox/commands/swapon/mod.rs

@@ -0,0 +1 @@
+