rustjail: get home dir using nix crate

Get user's home dir using `nix::unistd` crate instead of `utils` crate,
and remove useless code from agent.

Fixes: #4209

Signed-off-by: Xuewei Niu <justxuewei@apache.org>
This commit is contained in:
Xuewei Niu 2022-05-23 17:23:54 +08:00
parent 2c238c8504
commit 6ecea84bc5
3 changed files with 11 additions and 129 deletions

View File

@ -42,7 +42,7 @@ use nix::pty;
use nix::sched::{self, CloneFlags};
use nix::sys::signal::{self, Signal};
use nix::sys::stat::{self, Mode};
use nix::unistd::{self, fork, ForkResult, Gid, Pid, Uid};
use nix::unistd::{self, fork, ForkResult, Gid, Pid, Uid, User};
use std::os::unix::fs::MetadataExt;
use std::os::unix::io::AsRawFd;
@ -64,8 +64,6 @@ use rlimit::{setrlimit, Resource, Rlim};
use tokio::io::AsyncBufReadExt;
use tokio::sync::Mutex;
use crate::utils;
pub const EXEC_FIFO_FILENAME: &str = "exec.fifo";
const INIT: &str = "INIT";
@ -665,12 +663,17 @@ fn do_init_child(cwfd: RawFd) -> Result<()> {
}
}
// set the "HOME" env getting from "/etc/passwd", if
// there's no uid entry in /etc/passwd, set "/" as the
// home env.
if env::var_os(HOME_ENV_KEY).is_none() {
let home_dir = utils::home_dir(guser.uid).unwrap_or_else(|_| String::from("/"));
env::set_var(HOME_ENV_KEY, home_dir);
// try to set "HOME" env by uid
if let Ok(Some(user)) = User::from_uid(Uid::from_raw(guser.uid)) {
if let Ok(user_home_dir) = user.dir.into_os_string().into_string() {
env::set_var(HOME_ENV_KEY, user_home_dir);
}
}
// set default home dir as "/" if "HOME" env is still empty
if env::var_os(HOME_ENV_KEY).is_none() {
env::set_var(HOME_ENV_KEY, String::from("/"));
}
}
let exec_file = Path::new(&args[0]);

View File

@ -41,7 +41,6 @@ pub mod seccomp;
pub mod specconv;
pub mod sync;
pub mod sync_with_async;
pub mod utils;
pub mod validator;
use std::collections::HashMap;

View File

@ -1,120 +0,0 @@
// Copyright (c) 2021 Ant Group
//
// SPDX-License-Identifier: Apache-2.0
//
use anyhow::{anyhow, Context, Result};
use libc::gid_t;
use libc::uid_t;
use std::fs::File;
use std::io::{BufRead, BufReader};
const PASSWD_FILE: &str = "/etc/passwd";
// An entry from /etc/passwd
#[derive(Debug, PartialEq, PartialOrd)]
pub struct PasswdEntry {
// username
pub name: String,
// user password
pub passwd: String,
// user id
pub uid: uid_t,
// group id
pub gid: gid_t,
// user Information
pub gecos: String,
// home directory
pub dir: String,
// User's Shell
pub shell: String,
}
// get an entry for a given `uid` from `/etc/passwd`
fn get_entry_by_uid(uid: uid_t, path: &str) -> Result<PasswdEntry> {
let file = File::open(path).with_context(|| format!("open file {}", path))?;
let mut reader = BufReader::new(file);
let mut line = String::new();
loop {
line.clear();
match reader.read_line(&mut line) {
Ok(0) => return Err(anyhow!(format!("file {} is empty", path))),
Ok(_) => (),
Err(e) => {
return Err(anyhow!(format!(
"failed to read file {} with {:?}",
path, e
)))
}
}
if line.starts_with('#') {
continue;
}
let parts: Vec<&str> = line.split(':').map(|part| part.trim()).collect();
if parts.len() != 7 {
continue;
}
match parts[2].parse() {
Err(_e) => continue,
Ok(new_uid) => {
if uid != new_uid {
continue;
}
let entry = PasswdEntry {
name: parts[0].to_string(),
passwd: parts[1].to_string(),
uid: new_uid,
gid: parts[3].parse().unwrap_or(0),
gecos: parts[4].to_string(),
dir: parts[5].to_string(),
shell: parts[6].to_string(),
};
return Ok(entry);
}
}
}
}
pub fn home_dir(uid: uid_t) -> Result<String> {
get_entry_by_uid(uid, PASSWD_FILE).map(|entry| entry.dir)
}
#[cfg(test)]
mod tests {
use super::*;
use std::io::Write;
use tempfile::Builder;
#[test]
fn test_get_entry_by_uid() {
let tmpdir = Builder::new().tempdir().unwrap();
let tmpdir_path = tmpdir.path().to_str().unwrap();
let temp_passwd = format!("{}/passwd", tmpdir_path);
let mut tempf = File::create(temp_passwd.as_str()).unwrap();
let passwd_entries = "root:x:0:0:root:/root0:/bin/bash
root:x:1:0:root:/root1:/bin/bash
#root:x:1:0:root:/rootx:/bin/bash
root:x:2:0:root:/root2:/bin/bash
root:x:3:0:root:/root3
root:x:3:0:root:/root3:/bin/bash";
writeln!(tempf, "{}", passwd_entries).unwrap();
let entry = get_entry_by_uid(0, temp_passwd.as_str()).unwrap();
assert_eq!(entry.dir.as_str(), "/root0");
let entry = get_entry_by_uid(1, temp_passwd.as_str()).unwrap();
assert_eq!(entry.dir.as_str(), "/root1");
let entry = get_entry_by_uid(2, temp_passwd.as_str()).unwrap();
assert_eq!(entry.dir.as_str(), "/root2");
let entry = get_entry_by_uid(3, temp_passwd.as_str()).unwrap();
assert_eq!(entry.dir.as_str(), "/root3");
}
}