ReZygisk/zygiskd/src/root_impl/kernelsu.rs

use anyhow::{bail, Result};
use nix::libc::prctl;
use crate::constants::{MIN_KSU_VERSION, MAX_KSU_VERSION};

const KERNEL_SU_OPTION: i32 = 0xdeadbeefu32 as i32;

const CMD_GET_VERSION: usize = 2;
const CMD_GET_ALLOW_LIST: usize = 5;
const CMD_GET_DENY_LIST: usize = 6;

pub fn is_kernel_su() -> Result<bool> {
    let mut version = 0;
    unsafe { prctl(KERNEL_SU_OPTION, CMD_GET_VERSION, &mut version as *mut i32) };
    return match version {
        0 => Ok(false),
        MIN_KSU_VERSION..=MAX_KSU_VERSION => Ok(true),
        1..=MIN_KSU_VERSION => bail!("KernelSU version too old: {}", version),
        _ => bail!("KernelSU version abnormal: {}", version)
    }
}

pub fn uid_on_allowlist(uid: i32) -> bool {
    let mut size = 1024u32;
    let mut uids = vec![0; size as usize];
    unsafe { prctl(KERNEL_SU_OPTION, CMD_GET_ALLOW_LIST, uids.as_mut_ptr(), &mut size as *mut u32) };
    uids.resize(size as usize, 0);
    uids.contains(&uid)
}

pub fn uid_on_denylist(uid: i32) -> bool {
    let mut size = 1024u32;
    let mut uids = vec![0; size as usize];
    unsafe { prctl(KERNEL_SU_OPTION, CMD_GET_DENY_LIST, uids.as_mut_ptr(), &mut size as *mut u32) };
    uids.resize(size as usize, 0);
    uids.contains(&uid)
}