Prepare runguard

Cargo.toml

@@ -1,3 +1,3 @@
 [workspace]
-members = ["judge-core", "judger"]
-resolver = "2"
+members = ["judge-core", "judger", "runguard"]
+resolver = "2"

runguard/.gitignore

@@ -0,0 +1 @@
+metafile.txt

runguard/Cargo.toml

@@ -0,0 +1,13 @@
+[package]
+name = "runguard"
+version = "0.1.0"
+edition = "2021"
+build = "build.rs"
+
+[dependencies]
+libc = "0.2"
+nix = { version = "0.29", features = ["signal"] }
+
+clap = { version = "4", features = ["derive"] }
+chrono = "0.4"
+humantime = "2"

runguard/README.md

@@ -0,0 +1,5 @@
+# runguard
+
+A Rust version of
+[Domjudge runguard](https://github.com/DOMjudge/domjudge/blob/main/judge/runguard.cc)
+written in C++.

runguard/build.rs

@@ -0,0 +1,3 @@
+fn main() {
+    println!("cargo:rustc-link-lib=cgroup");
+}

runguard/src/cgroup.rs

@@ -0,0 +1,125 @@
+use std::ffi::CString;
+use std::fs::File;
+use std::io::{self, BufRead};
+use std::os::raw::c_char;
+
+extern "C" {
+    fn cgroup_new_cgroup(name: *const c_char) -> *mut libc::c_void;
+    fn cgroup_strerror(err: i32) -> *const c_char;
+}
+
+pub enum CGroupError {
+    ECGROUPNOTCOMPILED = 50000,
+    ECGROUPNOTMOUNTED,
+    ECGROUPNOTEXIST,
+    ECGROUPNOTCREATED,
+    ECGROUPSUBSYSNOTMOUNTED,
+    ECGROUPNOTOWNER,
+    /** Controllers bound to different mount points */
+    ECGROUPMULTIMOUNTED,
+    /* This is the stock error. Default error. @todo really? */
+    ECGROUPNOTALLOWED,
+    ECGMAXVALUESEXCEEDED,
+    ECGCONTROLLEREXISTS,
+    ECGVALUEEXISTS,
+    ECGINVAL,
+    ECGCONTROLLERCREATEFAILED,
+    ECGFAIL,
+    ECGROUPNOTINITIALIZED,
+    ECGROUPVALUENOTEXIST,
+    /**
+     * Represents error coming from other libraries like glibc. @c libcgroup
+     * users need to check cgroup_get_last_errno() upon encountering this
+     * error.
+     */
+    ECGOTHER,
+    ECGROUPNOTEQUAL,
+    ECGCONTROLLERNOTEQUAL,
+    /** Failed to parse rules configuration file. */
+    ECGROUPPARSEFAIL,
+    /** Rules list does not exist. */
+    ECGROUPNORULES,
+    ECGMOUNTFAIL,
+    /**
+     * Not an real error, it just indicates that iterator has come to end
+     * of sequence and no more items are left.
+     */
+    ECGEOF = 50023,
+    /** Failed to parse config file (cgconfig.conf). */
+    ECGCONFIGPARSEFAIL,
+    ECGNAMESPACEPATHS,
+    ECGNAMESPACECONTROLLER,
+    ECGMOUNTNAMESPACE,
+    ECGROUPUNSUPP,
+    ECGCANTSETVALUE,
+    /** Removing of a group failed because it was not empty. */
+    ECGNONEMPTY,
+}
+
+struct CGroup {
+    cgroup: *mut libc::c_void,
+}
+
+impl CGroup {
+    fn new(name: &str) -> Self {
+        let cgroup_name = CString::new(name).expect("CString::new failed");
+        unsafe {
+            let cgroup = cgroup_new_cgroup(cgroup_name.as_ptr());
+            if cgroup.is_null() {
+                eprintln!("Failed to create new cgroup");
+            } else {
+                println!("Successfully created new cgroup {}", name);
+            }
+            CGroup { cgroup }
+        }
+    }
+}
+
+fn cgroup_is_v2() -> bool {
+    let file = match File::open("/proc/mounts") {
+        Ok(file) => file,
+        Err(_) => {
+            eprintln!("Error opening /proc/mounts");
+            return false;
+        }
+    };
+
+    let reader = io::BufReader::new(file);
+    for line in reader.lines() {
+        if let Ok(line) = line {
+            let parts: Vec<&str> = line.split_whitespace().collect();
+            if parts.len() >= 3 && parts[1] == "/sys/fs/cgroup" && parts[2] == "cgroup2" {
+                return true;
+            }
+        }
+    }
+
+    false
+}
+
+pub fn cgroup_strerror_safe(err: i32) -> String {
+    unsafe {
+        let errstr = cgroup_strerror(err);
+        let errstr = std::ffi::CStr::from_ptr(errstr).to_str().unwrap();
+        errstr.to_string()
+    }
+}
+
+#[test]
+fn test_cgroup() {
+    let _ = CGroup::new("my_cgroup");
+
+    if cgroup_is_v2() {
+        println!("cgroup v2 is enabled");
+    } else {
+        println!("cgroup v2 is not enabled");
+    }
+}
+
+#[test]
+fn test_cgroup_strerror() {
+    println!(
+        "{}",
+        cgroup_strerror_safe(CGroupError::ECGROUPNOTCOMPILED as i32)
+    );
+}

runguard/src/cli.rs

@@ -0,0 +1,105 @@
+use std::path;
+
+use clap::Parser;
+
+use crate::types::SoftHardTime;
+
+#[derive(Parser)]
+#[command(
+    override_usage = "runguard [OPTION]... <COMMAND>...",
+    about = "Run COMMAND with specified options.",
+    after_help = "Note that root privileges are needed for the `root' and `user' options. \
+If `user' is set, then `group' defaults to the same to prevent security issues, \
+since otherwise the process would retain group root permissions. \
+The COMMAND path is relative to the changed ROOT directory if specified. \
+TIME may be specified as a float; two floats separated by `:' are treated as soft and hard limits. \
+The runtime written to file is that of the last of wall/cpu time options set, \
+and defaults to CPU time when neither is set. \
+When run setuid without the `user' option, the user ID is set to the real user ID."
+)]
+pub struct Cli {
+    // /// run COMMAND with root directory set to ROOT
+    // #[arg(short, long)]
+    // pub root: String,
+
+    // /// run COMMAND as user with username or ID USER
+    // #[arg(short, long)]
+    // pub user: String,
+
+    // /// run COMMAND under group with name or ID GROUP
+    // #[arg(short, long)]
+    // pub group: String,
+
+    // /// change to directory DIR after setting root directory
+    // #[arg(short = 'd', long, value_name = "DIR")]
+    // pub chdir: String,
+
+    // For `TIME` values, the format is `soft:hard`.
+    /// kill COMMAND after TIME wallclock seconds
+    #[arg(short = 't', long, value_name = "TIME")]
+    pub walltime: SoftHardTime,
+
+    /// set maximum CPU time to TIME seconds
+    #[arg(short = 'C', long, value_name = "TIME")]
+    pub cputime: SoftHardTime,
+
+    // /// set total memory limit to SIZE kB
+    // #[arg(short = 'm', long, value_name = "SIZE")]
+    // pub memsize: u64,
+
+    // /// set maximum created filesize to SIZE kB
+    // #[arg(short = 'f', long, value_name = "SIZE")]
+    // pub filesize: u64,
+
+    // /// set maximum no. processes to N
+    // #[arg(short = 'p', long, value_name = "N")]
+    // pub nproc: u64,
+
+    // /// use only processor number ID (or set, e.g. \"0,2-3\")
+    // #[arg(short = 'P', long, value_name = "ID")]
+    // pub cpuset: String,
+
+    // /// disable core dumps
+    // #[arg(short = 'c', long)]
+    // pub no_core: bool,
+
+    // /// redirect COMMAND stdout output to FILE
+    // #[arg(short = 'o', long, value_name = "FILE")]
+    // pub stdout: path::PathBuf,
+
+    // /// redirect COMMAND stderr output to FILE
+    // #[arg(short = 'e', long, value_name = "FILE")]
+    // pub stderr: path::PathBuf,
+
+    // /// truncate COMMAND stdout/stderr streams at SIZE kB
+    // #[arg(short, long, value_name = "SIZE")]
+    // pub streamsize: u64,
+
+    // /// preserve environment variables (default only PATH)
+    // #[arg(short = 'E', long)]
+    // pub environment: String,
+
+    // /// write metadata (runtime, exitcode, etc.) to FILE
+    // #[arg(short = 'M', long, value_name = "FILE")]
+    // pub metadata: path::PathBuf,
+
+    // /// process ID of runpipe to send SIGUSR1 signal when
+    // /// timelimit is reached
+    // #[arg(short = 'U', long, value_name = "PID")]
+    // pub runpipepid: u32,
+
+    // /// display some extra warnings and information
+    // #[arg(short, long)]
+    // pub verbose: bool,
+
+    // /// suppress all warnings and verbose output
+    // #[arg(short, long)]
+    // pub quiet: bool,
+
+    // /// output version information and exit
+    // #[arg(long)]
+    // pub version: bool,
+
+    // #[arg(required = true)]
+    // pub command: Vec<String>,
+}