No hex patch

zygiskd/src/constants.rs

@@ -19,15 +19,12 @@ pub const MAX_LOG_LEVEL: LevelFilter = LevelFilter::Info;
 pub const PROP_NATIVE_BRIDGE: &str = "ro.dalvik.vm.native.bridge";
 pub const PROP_CTL_RESTART: &str = "ctl.restart";
 pub const ZYGISK_LOADER: &str = "libzygisk_loader.so";
-
-pub const SOCKET_PLACEHOLDER: &str = "socket_placeholder";
+pub const ZYGISK_MAGIC: &str = "/system/zygisk_magic";
 
 pub const PATH_MODULES_DIR: &str = "..";
 pub const PATH_MODULE_PROP: &str = "module.prop";
 pub const PATH_ZYGISKD32: &str = "bin/zygiskd32";
 pub const PATH_ZYGISKD64: &str = "bin/zygiskd64";
-pub const PATH_TMP_DIR: &str = concatcp!("/dev/", SOCKET_PLACEHOLDER);
-pub const PATH_TMP_PROP: &str = concatcp!("/dev/", SOCKET_PLACEHOLDER, "/module.prop");
 
 pub const STATUS_LOADED: &str = "😋 Zygisksu is loaded";
 pub const STATUS_CRASHED: &str = "❌ Zygiskd has crashed";

zygiskd/src/magic.rs

@@ -0,0 +1,19 @@
+use std::fs;
+use anyhow::Result;
+use crate::constants;
+use crate::utils::LateInit;
+
+pub static MAGIC: LateInit<String> = LateInit::new();
+pub static PATH_TMP_DIR: LateInit<String> = LateInit::new();
+pub static PATH_TMP_PROP: LateInit<String> = LateInit::new();
+
+pub fn setup() -> Result<()> {
+    let name = fs::read_to_string(constants::ZYGISK_MAGIC)?;
+    let path_tmp_dir = format!("/dev/{}", name);
+    let path_tmp_prop = format!("{}/module.prop", path_tmp_dir);
+
+    MAGIC.init(name);
+    PATH_TMP_DIR.init(path_tmp_dir);
+    PATH_TMP_PROP.init(path_tmp_prop);
+    Ok(())
+}

zygiskd/src/main.rs

@@ -3,6 +3,7 @@
 mod companion;
 mod constants;
 mod dl;
+mod magic;
 mod root_impl;
 mod utils;
 mod watchdog;
@@ -39,6 +40,7 @@ fn init_android_logger(tag: &str) {
 
 fn start() -> Result<()> {
     root_impl::setup();
+    magic::setup()?;
     let cli = Args::parse();
     match cli.command {
         Commands::Watchdog => watchdog::entry()?,

zygiskd/src/utils.rs

@@ -5,6 +5,7 @@ use std::ffi::c_char;
 use std::os::fd::FromRawFd;
 use std::os::unix::net::UnixListener;
 use nix::sys::socket::{AddressFamily, SockFlag, SockType, UnixAddr};
+use once_cell::sync::OnceCell;
 use rand::distributions::{Alphanumeric, DistString};
 
 #[cfg(target_pointer_width = "64")]
@@ -18,6 +19,27 @@ macro_rules! lp_select {
     ($lp32:expr, $lp64:expr) => { $lp32 };
 }
 
+pub struct LateInit<T> {
+    cell: OnceCell<T>,
+}
+
+impl<T> LateInit<T> {
+    pub const fn new() -> Self {
+        LateInit { cell: OnceCell::new() }
+    }
+
+    pub fn init(&self, value: T) {
+        assert!(self.cell.set(value).is_ok())
+    }
+}
+
+impl<T> std::ops::Deref for LateInit<T> {
+    type Target = T;
+    fn deref(&self) -> &T {
+        self.cell.get().unwrap()
+    }
+}
+
 pub fn random_string() -> String {
     Alphanumeric.sample_string(&mut rand::thread_rng(), 8)
 }

zygiskd/src/watchdog.rs

@@ -1,4 +1,4 @@
-use crate::{constants, root_impl, utils};
+use crate::{constants, magic, root_impl, utils};
 use anyhow::{bail, Result};
 use nix::unistd::{getgid, getuid, Pid};
 use std::process::{Child, Command};
@@ -12,10 +12,10 @@ use binder::IBinder;
 use nix::errno::Errno;
 use nix::libc;
 use nix::sys::signal::{kill, Signal};
-use once_cell::sync::OnceCell;
+use crate::utils::LateInit;
 
-static LOCK: OnceCell<UnixListener> = OnceCell::new();
-static PROP_SECTIONS: OnceCell<[String; 2]> = OnceCell::new();
+static LOCK: LateInit<UnixListener> = LateInit::new();
+static PROP_SECTIONS: LateInit<[String; 2]> = LateInit::new();
 
 pub fn entry() -> Result<()> {
     log::info!("Start zygisksu watchdog");
@@ -55,9 +55,9 @@ fn check_permission() -> Result<()> {
 
 fn ensure_single_instance() -> Result<()> {
     log::info!("Ensure single instance");
-    let name = String::from("zygiskwd") + constants::SOCKET_PLACEHOLDER;
+    let name = format!("zygiskwd{}", magic::MAGIC.as_str());
     match utils::abstract_namespace_socket(&name) {
-        Ok(socket) => { let _ = LOCK.set(socket); }
+        Ok(socket) => LOCK.init(socket),
         Err(e) => bail!("Failed to acquire lock: {e}. Maybe another instance is running?")
     }
     Ok(())
@@ -91,15 +91,15 @@ fn mount_prop() -> Result<()> {
             sections[section].push('\n');
         }
     }
-    let _ = PROP_SECTIONS.set(sections);
+    PROP_SECTIONS.init(sections);
 
-    fs::create_dir(constants::PATH_TMP_DIR)?;
-    fs::File::create(constants::PATH_TMP_PROP)?;
+    fs::create_dir(magic::PATH_TMP_DIR.as_str())?;
+    fs::File::create(magic::PATH_TMP_PROP.as_str())?;
 
     // FIXME: sys_mount cannot be compiled on 32 bit
     unsafe {
         let r = libc::mount(
-            CString::new(constants::PATH_TMP_PROP)?.as_ptr(),
+            CString::new(magic::PATH_TMP_PROP.as_str())?.as_ptr(),
             CString::new(module_prop)?.as_ptr(),
             std::ptr::null(),
             libc::MS_BIND,
@@ -112,13 +112,12 @@ fn mount_prop() -> Result<()> {
 }
 
 fn set_prop_hint(hint: &str) -> Result<()> {
-    let mut file = fs::File::create(constants::PATH_TMP_PROP)?;
-    let sections = PROP_SECTIONS.get().unwrap();
-    file.write_all(sections[0].as_bytes())?;
+    let mut file = fs::File::create(magic::PATH_TMP_PROP.as_str())?;
+    file.write_all(PROP_SECTIONS[0].as_bytes())?;
     file.write_all(b"[")?;
     file.write_all(hint.as_bytes())?;
     file.write_all(b"] ")?;
-    file.write_all(sections[1].as_bytes())?;
+    file.write_all(PROP_SECTIONS[1].as_bytes())?;
     Ok(())
 }
 

zygiskd/src/zygiskd.rs

@@ -1,6 +1,6 @@
 use crate::constants::DaemonSocketAction;
 use crate::utils::UnixStreamExt;
-use crate::{constants, lp_select, root_impl, utils};
+use crate::{constants, lp_select, magic, root_impl, utils};
 use anyhow::{bail, Result};
 use memfd::Memfd;
 use nix::{
@@ -135,7 +135,7 @@ fn create_memfd(so_path: &PathBuf) -> Result<Memfd> {
 fn create_daemon_socket() -> Result<UnixListener> {
     utils::set_socket_create_context("u:r:zygote:s0")?;
     let prefix = lp_select!("zygiskd32", "zygiskd64");
-    let name = String::from(prefix) + constants::SOCKET_PLACEHOLDER;
+    let name = format!("{}{}", prefix, magic::MAGIC.as_str());
     let listener = utils::abstract_namespace_socket(&name)?;
     log::debug!("Daemon socket: {name}");
     Ok(listener)