Implement su_daemon in Rust

native/src/core/lib.rs

@@ -6,12 +6,20 @@
 #![feature(unix_socket_peek)]
 #![allow(clippy::missing_safety_doc)]
 
-use base::Utf8CStr;
+use crate::ffi::SuRequest;
+use crate::socket::Encodable;
+use base::{libc, Utf8CStr};
+use cxx::{type_id, ExternType};
 use daemon::{daemon_entry, MagiskD};
+use derive::Decodable;
 use logging::{android_logging, setup_logfile, zygisk_close_logd, zygisk_get_logd, zygisk_logging};
 use mount::{clean_mounts, find_preinit_device, revert_unmount};
 use resetprop::{persist_delete_prop, persist_get_prop, persist_get_props, persist_set_prop};
 use socket::{recv_fd, recv_fds, send_fd, send_fds};
+use std::fs::File;
+use std::mem::ManuallyDrop;
+use std::ops::DerefMut;
+use std::os::fd::FromRawFd;
 use zygisk::zygisk_should_load_module;
 
 #[path = "../include/consts.rs"]
@@ -53,44 +61,6 @@ pub mod ffi {
         END,
     }
 
-    extern "C++" {
-        include!("include/resetprop.hpp");
-
-        #[cxx_name = "prop_cb"]
-        type PropCb;
-        unsafe fn get_prop_rs(name: *const c_char, persist: bool) -> String;
-        unsafe fn prop_cb_exec(
-            cb: Pin<&mut PropCb>,
-            name: *const c_char,
-            value: *const c_char,
-            serial: u32,
-        );
-    }
-
-    unsafe extern "C++" {
-        #[namespace = "rust"]
-        #[cxx_name = "Utf8CStr"]
-        type Utf8CStrRef<'a> = base::ffi::Utf8CStrRef<'a>;
-
-        include!("include/core.hpp");
-
-        #[cxx_name = "get_magisk_tmp_rs"]
-        fn get_magisk_tmp() -> Utf8CStrRef<'static>;
-        #[cxx_name = "resolve_preinit_dir_rs"]
-        fn resolve_preinit_dir(base_dir: Utf8CStrRef) -> String;
-        fn setup_magisk_env() -> bool;
-        fn check_key_combo() -> bool;
-        fn disable_modules();
-        fn exec_common_scripts(stage: Utf8CStrRef);
-        fn exec_module_scripts(state: Utf8CStrRef, modules: &Vec<ModuleInfo>);
-        fn install_apk(apk: Utf8CStrRef);
-        fn uninstall_pkg(apk: Utf8CStrRef);
-        fn update_deny_flags(uid: i32, process: &str, flags: &mut u32);
-        fn initialize_denylist();
-        fn restore_zygisk_prop();
-        fn switch_mnt_ns(pid: i32) -> i32;
-    }
-
     enum DbEntryKey {
         RootAccess,
         SuMultiuserMode,
@@ -167,27 +137,86 @@ pub mod ffi {
         ProcessIsMagiskApp = 0x80000000,
     }
 
+    #[derive(Decodable)]
+    struct SuRequest {
+        target_uid: i32,
+        target_pid: i32,
+        login: bool,
+        keep_env: bool,
+        shell: String,
+        command: String,
+        context: String,
+        gids: Vec<u32>,
+    }
+
+    struct SuAppRequest<'a> {
+        uid: i32,
+        pid: i32,
+        eval_uid: i32,
+        mgr_pkg: &'a str,
+        mgr_uid: i32,
+        request: &'a SuRequest,
+    }
+
+    extern "C++" {
+        include!("include/resetprop.hpp");
+
+        #[cxx_name = "prop_cb"]
+        type PropCb;
+        unsafe fn get_prop_rs(name: *const c_char, persist: bool) -> String;
+        unsafe fn prop_cb_exec(
+            cb: Pin<&mut PropCb>,
+            name: *const c_char,
+            value: *const c_char,
+            serial: u32,
+        );
+    }
+
     unsafe extern "C++" {
+        #[namespace = "rust"]
+        #[cxx_name = "Utf8CStr"]
+        type Utf8CStrRef<'a> = base::ffi::Utf8CStrRef<'a>;
+        #[cxx_name = "ucred"]
+        type UCred = crate::UCred;
+
+        include!("include/core.hpp");
+
+        #[cxx_name = "get_magisk_tmp_rs"]
+        fn get_magisk_tmp() -> Utf8CStrRef<'static>;
+        #[cxx_name = "resolve_preinit_dir_rs"]
+        fn resolve_preinit_dir(base_dir: Utf8CStrRef) -> String;
+        fn setup_magisk_env() -> bool;
+        fn check_key_combo() -> bool;
+        fn disable_modules();
+        fn exec_common_scripts(stage: Utf8CStrRef);
+        fn exec_module_scripts(state: Utf8CStrRef, modules: &Vec<ModuleInfo>);
+        fn install_apk(apk: Utf8CStrRef);
+        fn uninstall_pkg(apk: Utf8CStrRef);
+        fn update_deny_flags(uid: i32, process: &str, flags: &mut u32);
+        fn initialize_denylist();
+        fn restore_zygisk_prop();
+        fn switch_mnt_ns(pid: i32) -> i32;
+        fn app_request(req: &SuAppRequest) -> i32;
+        fn app_notify(req: &SuAppRequest, policy: SuPolicy);
+        fn app_log(req: &SuAppRequest, policy: SuPolicy, notify: bool);
+        fn exec_root_shell(client: i32, pid: i32, req: &mut SuRequest, mode: MntNsMode);
+
         include!("include/sqlite.hpp");
 
-        fn sqlite3_errstr(code: i32) -> *const c_char;
-
         type sqlite3;
-        fn open_and_init_db() -> *mut sqlite3;
-
         type DbValues;
         type DbStatement;
 
+        fn sqlite3_errstr(code: i32) -> *const c_char;
+        fn open_and_init_db() -> *mut sqlite3;
         fn get_int(self: &DbValues, index: i32) -> i32;
         #[cxx_name = "get_str"]
         fn get_text(self: &DbValues, index: i32) -> &str;
-
         fn bind_text(self: Pin<&mut DbStatement>, index: i32, val: &str) -> i32;
         fn bind_int64(self: Pin<&mut DbStatement>, index: i32, val: i64) -> i32;
     }
 
     extern "Rust" {
-        fn rust_test_entry();
         fn android_logging();
         fn zygisk_logging();
         fn zygisk_close_logd();
@@ -205,11 +234,27 @@ pub mod ffi {
         fn send_fds(socket: i32, fds: &[i32]) -> bool;
         fn recv_fd(socket: i32) -> i32;
         fn recv_fds(socket: i32) -> Vec<i32>;
+        unsafe fn write_to_fd(self: &SuRequest, fd: i32);
 
         #[namespace = "rust"]
         fn daemon_entry();
     }
 
+    // Default constructors
+    extern "Rust" {
+        #[Self = DbSettings]
+        #[cxx_name = "New"]
+        fn default() -> DbSettings;
+
+        #[Self = RootSettings]
+        #[cxx_name = "New"]
+        fn default() -> RootSettings;
+
+        #[Self = SuRequest]
+        #[cxx_name = "New"]
+        fn default() -> SuRequest;
+    }
+
     // FFI for MagiskD
     extern "Rust" {
         type MagiskD;
@@ -220,6 +265,7 @@ pub mod ffi {
         fn zygisk_handler(&self, client: i32);
         fn zygisk_reset(&self, restore: bool);
         fn prune_su_access(&self);
+        fn su_daemon_handler(&self, client: i32, cred: &UCred);
         #[cxx_name = "get_manager"]
         unsafe fn get_manager_for_cxx(&self, user: i32, ptr: *mut CxxString, install: bool) -> i32;
         fn set_module_list(&self, module_list: Vec<ModuleInfo>);
@@ -234,14 +280,6 @@ pub mod ffi {
         #[cxx_name = "get_root_settings"]
         fn get_root_settings_for_cxx(&self, uid: i32, settings: &mut RootSettings) -> bool;
 
-        #[Self = DbSettings]
-        #[cxx_name = "New"]
-        fn default() -> DbSettings;
-
-        #[Self = RootSettings]
-        #[cxx_name = "New"]
-        fn default() -> RootSettings;
-
         #[Self = MagiskD]
         #[cxx_name = "Get"]
         fn get() -> &'static MagiskD;
@@ -253,7 +291,20 @@ pub mod ffi {
     }
 }
 
-fn rust_test_entry() {}
+#[repr(transparent)]
+pub struct UCred(pub libc::ucred);
+
+unsafe impl ExternType for UCred {
+    type Id = type_id!("ucred");
+    type Kind = cxx::kind::Trivial;
+}
+
+impl SuRequest {
+    unsafe fn write_to_fd(&self, fd: i32) {
+        let mut w = ManuallyDrop::new(File::from_raw_fd(fd));
+        self.encode(w.deref_mut()).ok();
+    }
+}
 
 pub fn get_prop(name: &Utf8CStr, persist: bool) -> String {
     unsafe { ffi::get_prop_rs(name.as_ptr(), persist) }