Partially cleanup MagiskInit code

native/src/init/getinfo.rs

@@ -1,5 +1,5 @@
-use crate::ffi::{BootConfig, MagiskInit};
-use base::{cstr, debug, BytesExt, FsPath, MappedFile, Utf8CStr};
+use crate::ffi::{backup_init, BootConfig, MagiskInit};
+use base::{cstr, debug, BytesExt, FsPath, MappedFile};
 use std::ffi::CStr;
 
 impl BootConfig {
@@ -33,6 +33,8 @@ impl MagiskInit {
             // Use the apex folder to determine whether 2SI (Android 10+)
             FsPath::from(cstr!("/apex")).exists() ||
             // If we still have no indication, parse the original init and see what's up
-            MappedFile::open(unsafe { Utf8CStr::from_ptr_unchecked(self.backup_init()) }).map(|map| map.contains(b"selinux_setup")).unwrap_or(false)
+            MappedFile::open(backup_init())
+                .map(|data| data.contains(b"selinux_setup"))
+                .unwrap_or(false)
     }
 }

native/src/init/init.hpp

@@ -1,10 +1,10 @@
 #include <base.hpp>
 #include <stream.hpp>
 
+#include "init-rs.hpp"
+
 #define DEFAULT_DT_DIR "/proc/device-tree/firmware/android"
-#define INIT_PATH  "/system/bin/init"
 #define REDIR_PATH "/data/magiskinit"
 
-int magisk_proxy_main(int argc, char *argv[]);
-
-#include "init-rs.hpp"
+int magisk_proxy_main(int, char *argv[]);
+rust::Utf8CStr backup_init();

native/src/init/init.rs

@@ -1,3 +1,4 @@
+use crate::ffi::backup_init;
 use crate::{
     ffi::{magisk_proxy_main, BootConfig, MagiskInit},
     logging::setup_klog,
@@ -5,7 +6,7 @@ use crate::{
 use base::{
     cstr, debug, info,
     libc::{basename, getpid, mount, umask},
-    raw_cstr, FsPath, LibcReturn, LoggedResult, ResultExt, Utf8CStr,
+    raw_cstr, FsPath, LibcReturn, LoggedResult, ResultExt,
 };
 use std::{
     ffi::{c_char, CStr},
@@ -63,7 +64,7 @@ impl MagiskInit {
     pub(crate) fn restore_ramdisk_init(&self) {
         FsPath::from(cstr!("/init")).remove().ok();
 
-        let orig_init = FsPath::from(unsafe { Utf8CStr::from_ptr_unchecked(self.backup_init()) });
+        let orig_init = FsPath::from(backup_init());
 
         if orig_init.exists() {
             orig_init.rename_to(FsPath::from(cstr!("/init"))).log_ok();

native/src/init/lib.rs

@@ -1,20 +1,21 @@
 #![feature(format_args_nl)]
 #![feature(once_cell_try)]
 #![feature(try_blocks)]
+#![allow(clippy::missing_safety_doc)]
 
 use logging::setup_klog;
-use mount::{is_device_mounted, switch_root};
-use rootdir::{collect_overlay_contexts, inject_magisk_rc, reset_overlay_contexts};
 // Has to be pub so all symbols in that crate is included
 pub use magiskpolicy;
+use mount::{is_device_mounted, switch_root};
+use rootdir::{collect_overlay_contexts, inject_magisk_rc, reset_overlay_contexts};
 
+mod getinfo;
+mod init;
 mod logging;
 mod mount;
 mod rootdir;
-mod getinfo;
-mod init;
-mod twostage;
 mod selinux;
+mod twostage;
 
 #[cxx::bridge]
 pub mod ffi {
@@ -23,6 +24,7 @@ pub mod ffi {
         key: String,
         value: String,
     }
+
     struct BootConfig {
         skip_initramfs: bool,
         force_normal_boot: bool,
@@ -43,6 +45,17 @@ pub mod ffi {
         config: BootConfig,
     }
 
+    unsafe extern "C++" {
+        include!("init.hpp");
+
+        #[namespace = "rust"]
+        #[cxx_name = "Utf8CStr"]
+        type Utf8CStrRef<'a> = base::ffi::Utf8CStrRef<'a>;
+
+        unsafe fn magisk_proxy_main(argc: i32, argv: *mut *mut c_char) -> i32;
+        fn backup_init() -> Utf8CStrRef<'static>;
+    }
+
     #[namespace = "rust"]
     extern "Rust" {
         fn setup_klog();
@@ -53,39 +66,32 @@ pub mod ffi {
         fn reset_overlay_contexts();
     }
 
+    // BootConfig
     extern "Rust" {
         fn print(self: &BootConfig);
-
-        fn patch_sepolicy(self: &MagiskInit, in_: Utf8CStrRef, out: Utf8CStrRef);
     }
-
     unsafe extern "C++" {
-        include!("../base/include/base.hpp");
-        include!("init.hpp");
-
-        #[namespace = "rust"]
-        #[cxx_name = "Utf8CStr"]
-        type Utf8CStrRef<'a> = base::ffi::Utf8CStrRef<'a>;
-
-        unsafe fn magisk_proxy_main(argc: i32, argv: *mut *mut c_char) -> i32;
-
         fn init(self: &mut BootConfig);
         type kv_pairs;
         fn set(self: &mut BootConfig, config: &kv_pairs);
+    }
 
+    // MagiskInit
+    extern "Rust" {
+        fn patch_sepolicy(self: &MagiskInit, src: Utf8CStrRef, out: Utf8CStrRef);
+        fn parse_config_file(self: &mut MagiskInit);
+    }
+    unsafe extern "C++" {
+        // Used in Rust
+        fn mount_system_root(self: &mut MagiskInit) -> bool;
+        fn patch_rw_root(self: &mut MagiskInit);
+        fn patch_ro_root(self: &mut MagiskInit);
+
+        // Used in C++
         unsafe fn setup_tmp(self: &MagiskInit, path: *const c_char);
         fn collect_devices(self: &MagiskInit);
         fn mount_preinit_dir(self: &MagiskInit);
         unsafe fn find_block(self: &MagiskInit, partname: *const c_char) -> u64;
-        fn mount_system_root(self: &mut MagiskInit) -> bool;
-
-        // Setup and patch root directory
-        fn parse_config_file(self: &mut MagiskInit);
-        fn patch_rw_root(self: &mut MagiskInit);
-        fn patch_ro_root(self: &mut MagiskInit);
-
-        // SELinux
         fn hijack_sepolicy(self: &mut MagiskInit) -> bool;
-        fn backup_init(self: &MagiskInit) -> *const c_char;
     }
 }

native/src/init/rootdir.cpp

@@ -283,16 +283,6 @@ static void extract_files(bool sbin) {
     }
 }
 
-void MagiskInit::parse_config_file() noexcept {
-    parse_prop_file("/data/.backup/.magisk", [&](auto key, auto value) -> bool {
-        if (key == "PREINITDEVICE") {
-            preinit_dev = std::string(value);
-            return false;
-        }
-        return true;
-    });
-}
-
 void MagiskInit::patch_ro_root() noexcept {
     mount_list.emplace_back("/data");
     parse_config_file();
@@ -427,7 +417,7 @@ void MagiskInit::patch_rw_root() noexcept {
     cp_afc(REDIR_PATH, "/sbin/magisk");
 }
 
-int magisk_proxy_main(int argc, char *argv[]) {
+int magisk_proxy_main(int, char *argv[]) {
     rust::setup_klog();
     LOGD("%s\n", __FUNCTION__);
 
@@ -463,7 +453,7 @@ static void unxz_init(const char *init_xz, const char *init) {
     unlink(init_xz);
 }
 
-const char *MagiskInit::backup_init() const noexcept {
+rust::Utf8CStr backup_init() {
     if (access("/.backup/init.xz", F_OK) == 0)
         unxz_init("/.backup/init.xz", "/.backup/init");
     return "/.backup/init";

native/src/init/rootdir.rs

@@ -1,7 +1,10 @@
+use crate::ffi::MagiskInit;
+use base::libc::O_RDONLY;
 use base::{
-    debug, libc, Directory, LibcReturn, LoggedResult, ResultExt, Utf8CStr, Utf8CStrBuf,
-    Utf8CStrBufArr, WalkResult,
+    cstr, debug, libc, BufReadExt, Directory, FsPath, LibcReturn, LoggedResult, ResultExt,
+    Utf8CStr, Utf8CStrBuf, Utf8CStrBufArr, WalkResult,
 };
+use std::io::BufReader;
 use std::{
     fs::File,
     io::Write,
@@ -110,3 +113,18 @@ on property:init.svc.zygote=stopped
 
     mem::forget(file)
 }
+
+impl MagiskInit {
+    pub(crate) fn parse_config_file(&mut self) {
+        if let Ok(fd) = FsPath::from(cstr!("/data/.backup/.magisk")).open(O_RDONLY) {
+            let mut reader = BufReader::new(fd);
+            reader.foreach_props(|key, val| {
+                if key == "PREINITDEVICE" {
+                    self.preinit_dev = val.to_string();
+                    return false;
+                }
+                true
+            })
+        }
+    }
+}

native/src/init/selinux.rs

@@ -1,11 +1,11 @@
 use crate::ffi::MagiskInit;
-use base::{cstr, debug, ffi::Utf8CStrRef, FsPath};
+use base::{cstr, debug, FsPath, Utf8CStr};
 use magiskpolicy::ffi::SePolicy;
 
 impl MagiskInit {
-    pub(crate) fn patch_sepolicy(self: &MagiskInit, in_: Utf8CStrRef, out: Utf8CStrRef) {
+    pub(crate) fn patch_sepolicy(self: &MagiskInit, src: &Utf8CStr, out: &Utf8CStr) {
         debug!("Patching monolithic policy");
-        let mut sepol = SePolicy::from_file(in_);
+        let mut sepol = SePolicy::from_file(src);
 
         sepol.magisk_rules();
 

native/src/sepolicy/lib.rs

@@ -78,7 +78,7 @@ pub mod ffi {
         #[Self = SePolicy]
         fn compile_split() -> SePolicy;
         #[Self = SePolicy]
-        unsafe fn from_data(data: *mut c_char, len: usize) -> SePolicy;
+        fn from_data(data: &[u8]) -> SePolicy;
     }
 
     extern "Rust" {

native/src/sepolicy/policydb.cpp

@@ -79,13 +79,13 @@ static void load_cil(struct cil_db *db, const char *file) {
     LOGD("cil_add [%s]\n", file);
 }
 
-SePolicy SePolicy::from_data(char *data, size_t len) noexcept {
+SePolicy SePolicy::from_data(rust::Slice<const uint8_t> data) noexcept {
     LOGD("Load policy from data\n");
 
     policy_file_t pf;
     policy_file_init(&pf);
-    pf.data = data;
-    pf.len = len;
+    pf.data = (char *) data.data();
+    pf.len = data.size();
     pf.type = PF_USE_MEMORY;
 
     auto db = static_cast<policydb_t *>(malloc(sizeof(policydb_t)));