Refactor overlay rc load in Rust, supporting module modification of rc

app/core/src/main/java/com/topjohnwu/magisk/test/AdditionalTest.kt

@@ -8,6 +8,7 @@ import androidx.test.uiautomator.Until
 import com.topjohnwu.magisk.core.model.module.LocalModule
 import com.topjohnwu.magisk.core.utils.RootUtils
 import com.topjohnwu.magisk.test.Environment.Companion.EMPTY_ZYGISK
+import com.topjohnwu.magisk.test.Environment.Companion.INIT_RC
 import com.topjohnwu.magisk.test.Environment.Companion.INVALID_ZYGISK
 import com.topjohnwu.magisk.test.Environment.Companion.MOUNT_TEST
 import com.topjohnwu.magisk.test.Environment.Companion.REMOVE_TEST
@@ -59,7 +60,7 @@ class AdditionalTest : BaseTest {
     fun testModuleCount() {
         var expected = 4
         if (Environment.mount()) expected++
-        if (Environment.preinit()) expected++
+        if (Environment.preinit()) expected += 2
         if (Environment.lsposed()) expected++
         if (Environment.shamiko()) expected++
         assertEquals("Module count incorrect", expected, modules.size)
@@ -118,6 +119,21 @@ class AdditionalTest : BaseTest {
         )
     }
 
+    @Test
+    fun testInitRc() {
+        assumeTrue(Environment.preinit())
+
+        assertNotNull("$INIT_RC is not installed", modules.find { it.id == INIT_RC })
+        assertEquals(
+            "Module init.rc is not applied",
+            "1", Shell.cmd("getprop ro.debug.magisk.rc").exec().out.first()
+        )
+        assertEquals(
+            "Module product init.rc is not applied",
+            "1", Shell.cmd("getprop ro.debug.magisk.product.rc").exec().out.first()
+        )
+    }
+
     @Test
     fun testEmptyZygiskModule() {
         val module = modules.find { it.id == EMPTY_ZYGISK }

app/core/src/main/java/com/topjohnwu/magisk/test/Environment.kt

@@ -62,6 +62,7 @@ class Environment : BaseTest {
         private const val MODULE_ERROR = "Module zip processing incorrect"
         const val MOUNT_TEST = "mount_test"
         const val SEPOLICY_RULE = "sepolicy_rule"
+        const val INIT_RC = "init_rc"
         const val INVALID_ZYGISK = "invalid_zygisk"
         const val REMOVE_TEST = "remove_test"
         const val REMOVE_TEST_MARKER = "/dev/.remove_test_removed"
@@ -144,6 +145,43 @@ class Environment : BaseTest {
         ).exec().isSuccess)
     }
 
+    private fun setupInitRcModule(root: ExtendedFile) {
+        val error = "$INIT_RC setup failed"
+        val path = root.getChildFile(INIT_RC)
+        assertTrue(error, path.mkdirs())
+        var initDir = path
+        val initRcOnR = RootUtils.fs.getFile("/system").getChildFile("etc").getChildFile("init").getChildFile("hw").getChildFile("init.rc")
+        if (initRcOnR.exists() && initRcOnR.isFile) {
+            // Android R+ /system/etc/init/hw
+            initDir = path.getChildFile("system").getChildFile("etc").getChildFile("init").getChildFile("hw")
+            assertTrue(error, initDir.mkdirs())
+        }
+
+        assertTrue(error, initDir.getChildFile("init_new.rc").createNewFile())
+
+        // Add init.rc patch
+        PrintStream(initDir.getChildFile("init_new.rc").newOutputStream()).use {
+            it.println("on post-fs")
+            it.println("    setprop ro.debug.magisk.rc 1")
+            it.println()
+        }
+
+        // rc in product
+        val productInitDir = path.getChildFile("system").getChildFile("product").getChildFile("etc").getChildFile("init")
+        assertTrue(error, productInitDir.mkdirs())
+        assertTrue(error, productInitDir.getChildFile("init_new_p.rc").createNewFile())
+        PrintStream(productInitDir.getChildFile("init_new_p.rc").newOutputStream()).use {
+            it.println("on post-fs")
+            it.println("    setprop ro.debug.magisk.product.rc 1")
+            it.println()
+        }
+
+        assertTrue(error, Shell.cmd(
+            "set_default_perm $path",
+            "copy_preinit_files"
+        ).exec().isSuccess)
+    }
+
     private fun setupEmptyZygiskModule(root: ExtendedFile) {
         val error = "$EMPTY_ZYGISK setup failed"
         val path = root.getChildFile(EMPTY_ZYGISK)
@@ -254,7 +292,10 @@ class Environment : BaseTest {
         val root = RootUtils.fs.getFile(Const.MODULE_PATH)
         val update = RootUtils.fs.getFile(MODULE_UPDATE_PATH)
         if (mount()) { setupMountTest(update) }
-        if (preinit()) { setupSepolicyRuleModule(update) }
+        if (preinit()) {
+            setupSepolicyRuleModule(update)
+            setupInitRcModule(update)
+        }
         setupSystemlessHost()
         setupEmptyZygiskModule(update)
         setupInvalidZygiskModule(update)

native/src/base/misc.rs

@@ -13,6 +13,12 @@ pub fn errno() -> &'static mut i32 {
     unsafe { &mut *libc::__errno() }
 }
 
+// Simple fork without double-fork or waitpid; nolibc-compatible.
+// Returns 0 in child, child pid in parent, -1 on error.
+pub fn xfork() -> i32 {
+    unsafe { libc::fork() }
+}
+
 // When len is 0, don't care whether buf is null or not
 #[inline]
 pub unsafe fn slice_from_ptr<'a, T>(buf: *const T, len: usize) -> &'a [T] {

native/src/init/init.rs

@@ -12,6 +12,7 @@ impl MagiskInit {
         Self {
             preinit_dev: String::new(),
             mount_list: Vec::new(),
+            rc_list: Vec::new(),
             overlay_con: Vec::new(),
             argv,
             config: BootConfig {

native/src/init/lib.rs

@@ -4,7 +4,7 @@ use logging::setup_klog;
 // Has to be pub so all symbols in that crate is included
 pub use magiskpolicy;
 use mount::{is_device_mounted, switch_root};
-use rootdir::{OverlayAttr, inject_magisk_rc};
+use rootdir::OverlayAttr;
 
 #[path = "../include/consts.rs"]
 mod consts;
@@ -41,6 +41,7 @@ pub mod ffi {
     struct MagiskInit {
         preinit_dev: String,
         mount_list: Vec<String>,
+        rc_list: Vec<String>,
         argv: *mut *mut c_char,
         config: BootConfig,
         overlay_con: Vec<OverlayAttr>,
@@ -65,7 +66,6 @@ pub mod ffi {
     #[namespace = "rust"]
     extern "Rust" {
         fn setup_klog();
-        fn inject_magisk_rc(fd: i32, tmp_dir: Utf8CStrRef);
         fn switch_root(path: Utf8CStrRef);
         fn is_device_mounted(dev: u64, target: Pin<&mut CxxString>) -> bool;
     }
@@ -87,6 +87,10 @@ pub mod ffi {
         fn mount_overlay(self: &mut MagiskInit, dest: Utf8CStrRef);
         fn handle_sepolicy(self: &mut MagiskInit);
         fn restore_overlay_contexts(self: &MagiskInit);
+        fn load_overlay_rc(self: &mut MagiskInit, overlay: &Utf8CStrRef, module_path: &Utf8CStrRef);
+        fn handle_modules_rc(self: &mut MagiskInit, root_dir: &Utf8CStrRef);
+        fn patch_rc_scripts(self: &mut MagiskInit, src_path: Utf8CStrRef, tmp_path: Utf8CStrRef, writable: bool) -> bool;
+        fn patch_fissiond(self: &mut MagiskInit, tmp_path: Utf8CStrRef);
     }
     unsafe extern "C++" {
         // Used in Rust
@@ -99,6 +103,5 @@ pub mod ffi {
         fn collect_devices(self: &MagiskInit);
         fn mount_preinit_dir(self: &mut MagiskInit);
         unsafe fn find_block(self: &MagiskInit, partname: *const c_char) -> u64;
-        unsafe fn patch_fissiond(self: &mut MagiskInit, tmp_path: *const c_char);
     }
 }

native/src/init/rootdir.cpp

@@ -10,8 +10,6 @@
 
 using namespace std;
 
-static vector<string> rc_list;
-
 #define NEW_INITRC_DIR  "/system/etc/init/hw"
 #define INIT_RC         "init.rc"
 
@@ -40,168 +38,6 @@ static bool unxz(int fd, rust::Slice<const uint8_t> bytes) {
     return true;
 }
 
-// When return true, run patch_fissiond
-static bool patch_rc_scripts(const char *src_path, const char *tmp_path, bool writable) {
-    auto src_dir = xopen_dir(src_path);
-    if (!src_dir) return false;
-    int src_fd = dirfd(src_dir.get());
-
-    // If writable, directly modify the file in src_path, or else add to rootfs overlay
-    auto dest_dir = writable ? [&] {
-        return xopen_dir(src_path);
-    }() : [&] {
-        char buf[PATH_MAX] = {};
-        ssprintf(buf, sizeof(buf), ROOTOVL "%s", src_path);
-        xmkdirs(buf, 0755);
-        return xopen_dir(buf);
-    }();
-    if (!dest_dir) return false;
-    int dest_fd = dirfd(dest_dir.get());
-
-    // First patch init.rc
-    {
-        owned_fd src_rc = xopenat(src_fd, INIT_RC, O_RDONLY | O_CLOEXEC, 0);
-        if (src_rc < 0) return false;
-        if (writable) unlinkat(src_fd, INIT_RC, 0);
-        auto dest_rc = xopen_file(
-                xopenat(dest_fd, INIT_RC, O_WRONLY | O_CREAT | O_TRUNC | O_CLOEXEC, 0), "we");
-        if (!dest_rc) return false;
-        LOGD("Patching " INIT_RC " in %s\n", src_path);
-        file_readline(src_rc, [&dest_rc](Utf8CStr line) -> bool {
-            // Do not start vaultkeeper
-            if (line.sv().contains("start vaultkeeper")) {
-                LOGD("Remove vaultkeeper\n");
-                return true;
-            }
-            // Do not run flash_recovery
-            if (line.sv().starts_with("service flash_recovery")) {
-                LOGD("Remove flash_recovery\n");
-                fprintf(dest_rc.get(), "service flash_recovery /system/bin/true\n");
-                return true;
-            }
-            // Samsung's persist.sys.zygote.early will cause Zygote to start before post-fs-data
-            if (line.sv().starts_with("on property:persist.sys.zygote.early=")) {
-                LOGD("Invalidate persist.sys.zygote.early\n");
-                fprintf(dest_rc.get(), "on property:persist.sys.zygote.early.xxxxx=true\n");
-                return true;
-            }
-            // Else just write the line
-            fprintf(dest_rc.get(), "%s", line.c_str());
-            return true;
-        });
-
-        fprintf(dest_rc.get(), "\n");
-
-        // Inject custom rc scripts
-        for (auto &script : rc_list) {
-            // Replace template arguments of rc scripts with dynamic paths
-            replace_all(script, "${MAGISKTMP}", tmp_path);
-            fprintf(dest_rc.get(), "\n%s\n", script.data());
-        }
-        rc_list.clear();
-
-        // Inject Magisk rc scripts
-        rust::inject_magisk_rc(fileno(dest_rc.get()), tmp_path);
-
-        fclone_attr(src_rc, fileno(dest_rc.get()));
-    }
-
-    // Then patch init.zygote*.rc
-    for (dirent *entry; (entry = readdir(src_dir.get()));) {
-        {
-            auto name = std::string_view(entry->d_name);
-            if (!name.starts_with("init.zygote") || !name.ends_with(".rc")) continue;
-        }
-        owned_fd src_rc = xopenat(src_fd, entry->d_name, O_RDONLY | O_CLOEXEC, 0);
-        if (src_rc < 0) continue;
-        if (writable) unlinkat(src_fd, entry->d_name, 0);
-        auto dest_rc = xopen_file(
-                xopenat(dest_fd, entry->d_name, O_WRONLY | O_CREAT | O_TRUNC | O_CLOEXEC, 0), "we");
-        if (!dest_rc) continue;
-        LOGD("Patching %s in %s\n", entry->d_name, src_path);
-        file_readline(src_rc, [&dest_rc, &tmp_path](Utf8CStr line) -> bool {
-            if (line.sv().starts_with("service zygote ")) {
-                LOGD("Inject zygote restart\n");
-                fprintf(dest_rc.get(), "%s", line.c_str());
-                fprintf(dest_rc.get(),
-                        "    onrestart exec " MAGISK_PROC_CON " 0 0 -- %s/magisk --zygote-restart\n", tmp_path);
-                return true;
-            }
-            fprintf(dest_rc.get(), "%s", line.c_str());
-            return true;
-        });
-        fclone_attr(src_rc, fileno(dest_rc.get()));
-    }
-
-    return faccessat(src_fd, "init.fission_host.rc", F_OK, 0) == 0;
-}
-
-void MagiskInit::patch_fissiond(const char *tmp_path) noexcept {
-    {
-        LOGD("Patching fissiond\n");
-        mmap_data fissiond("/system/bin/fissiond", false);
-        for (size_t off : fissiond.patch(
-                "ro.build.system.fission_single_os",
-                "ro.build.system.xxxxxxxxxxxxxxxxx"))
-        {
-            LOGD("Patch @ %08zX [ro.build.system.fission_single_os] -> "
-                 "[ro.build.system.xxxxxxxxxxxxxxxxx]\n", off);
-        }
-        mkdirs(ROOTOVL "/system/bin", 0755);
-        if (auto target_fissiond = xopen_file(ROOTOVL "/system/bin/fissiond", "we")) {
-            fwrite(fissiond.data(), 1, fissiond.size(), target_fissiond.get());
-            clone_attr("/system/bin/fissiond", ROOTOVL "/system/bin/fissiond");
-        }
-    }
-    LOGD("hijack isolated\n");
-    auto hijack = xopen_file("/sys/devices/system/cpu/isolated", "re");
-    mkfifo(INTLROOT "/isolated", 0777);
-    xmount(INTLROOT "/isolated", "/sys/devices/system/cpu/isolated", nullptr, MS_BIND, nullptr);
-    if (!xfork()) {
-        auto dest = xopen_file(INTLROOT "/isolated", "we");
-        LOGD("hijacked isolated\n");
-        xumount2("/sys/devices/system/cpu/isolated", MNT_DETACH);
-        unlink(INTLROOT "/isolated");
-        string content = full_read(fileno(hijack.get()));
-        {
-            string target = "/dev/cells/cell2"s + tmp_path;
-            xmkdirs(target.data(), 0);
-            xmount(tmp_path, target.data(), nullptr, MS_BIND | MS_REC, nullptr);
-            mount_overlay("/dev/cells/cell2");
-        }
-        fprintf(dest.get(), "%s", content.data());
-        exit(0);
-    }
-}
-
-static void load_overlay_rc(const char *overlay) {
-    auto dir = open_dir(overlay);
-    if (!dir) return;
-
-    int dfd = dirfd(dir.get());
-    // Do not allow overwrite init.rc
-    unlinkat(dfd, INIT_RC, 0);
-
-    // '/' + name + '\0'
-    char buf[NAME_MAX + 2];
-    buf[0] = '/';
-    for (dirent *entry; (entry = xreaddir(dir.get()));) {
-        if (!string_view(entry->d_name).ends_with(".rc")) {
-            continue;
-        }
-        strscpy(buf + 1, entry->d_name, sizeof(buf) - 1);
-        if (access(buf, F_OK) == 0) {
-            LOGD("Replace rc script [%s]\n", entry->d_name);
-        } else {
-            LOGD("Found rc script [%s]\n", entry->d_name);
-            int rc = xopenat(dfd, entry->d_name, O_RDONLY | O_CLOEXEC);
-            rc_list.push_back(full_read(rc));
-            close(rc);
-            unlinkat(dfd, entry->d_name, 0);
-        }
-    }
-}
-
 static void recreate_sbin(const char *mirror, bool use_bind_mount) {
     auto dp = xopen_dir(mirror);
     int src = dirfd(dp.get());
@@ -306,12 +142,14 @@ void MagiskInit::patch_ro_root() noexcept {
         close(dest);
     }
 
-    load_overlay_rc(ROOTOVL);
+    load_overlay_rc(ROOTOVL, "");
     if (access(ROOTOVL "/sbin", F_OK) == 0) {
         // Move files in overlay.d/sbin into tmp_dir
         mv_path(ROOTOVL "/sbin", ".");
     }
 
+    handle_modules_rc(ROOTOVL);
+
     // Patch init.rc
     bool p;
     if (access(NEW_INITRC_DIR "/" INIT_RC, F_OK) == 0) {
@@ -347,19 +185,22 @@ void MagiskInit::patch_rw_root() noexcept {
     link_path("/sbin", "/root");
 
     // Handle overlays
-    load_overlay_rc("/overlay.d");
+    load_overlay_rc("/overlay.d", "");
     mv_path("/overlay.d", "/");
     rm_rf("/data/overlay.d");
     rm_rf("/.backup");
 
-    // Patch init.rc
-    if (patch_rc_scripts("/", "/sbin", true))
-        patch_fissiond("/sbin");
-
     xmkdir(PRE_TMPSRC, 0);
     xmount("tmpfs", PRE_TMPSRC, "tmpfs", 0, "mode=755");
     xmkdir(PRE_TMPDIR, 0);
     setup_tmp(PRE_TMPDIR);
+
+    handle_modules_rc("/");
+
+    // Patch init.rc
+    if (patch_rc_scripts("/", "/sbin", true))
+        patch_fissiond("/sbin");
+
     chdir(PRE_TMPDIR);
 
     // Extract overlay archives