Use magiskd to setup files

native/jni/core/daemon.cpp

@@ -68,6 +68,9 @@ static void handle_request_async(int client, int code, ucred cred) {
         close(client);
         reboot();
         break;
+    case ZYGISK_REQUEST:
+        zygisk_handler(client, &cred);
+        break;
     default:
         close(client);
         break;
@@ -116,6 +119,7 @@ static void handle_request(int client) {
     case BOOT_COMPLETE:
     case SQLITE_CMD:
     case GET_PATH:
+    case MAGISKHIDE:
         if (!is_root) {
             write_int(client, ROOT_REQUIRED);
             goto done;
@@ -127,9 +131,9 @@ static void handle_request(int client) {
             goto done;
         }
         break;
-    case MAGISKHIDE:  // accept hide request from zygote
-        if (!is_root && !is_zygote) {
-            write_int(client, ROOT_REQUIRED);
+    case ZYGISK_REQUEST:
+        if (!is_zygote) {
+            write_int(client, DAEMON_ERROR);
             goto done;
         }
         break;
@@ -260,7 +264,7 @@ int connect_daemon(bool create) {
     if (connect(fd, (sockaddr*) &sun, len)) {
         if (!create || getuid() != UID_ROOT) {
             LOGE("No daemon is currently running!\n");
-            exit(1);
+            return 1;
         }
 
         if (fork_dont_care() == 0) {

native/jni/core/logging.cpp

@@ -158,6 +158,16 @@ void magisk_logging() {
     log_cb.ex = nop_ex;
 }
 
+#define alog(prio) [](auto fmt, auto ap){ \
+return __android_log_vprint(ANDROID_LOG_##prio, "Magisk", fmt, ap); }
+void android_logging() {
+    log_cb.d = alog(DEBUG);
+    log_cb.i = alog(INFO);
+    log_cb.w = alog(WARN);
+    log_cb.e = alog(ERROR);
+    log_cb.ex = nop_ex;
+}
+
 void start_log_daemon() {
     int fds[2];
     if (pipe2(fds, O_CLOEXEC) == 0) {

native/jni/include/daemon.hpp

@@ -25,6 +25,7 @@ enum : int {
     MAGISKHIDE,
     SQLITE_CMD,
     REMOVE_MODULES,
+    ZYGISK_REQUEST,
     DAEMON_CODE_END,
 };
 
@@ -47,12 +48,15 @@ enum : int {
 
 int connect_daemon(bool create = false);
 
+void android_logging();
+
 // Daemon handlers
 void post_fs_data(int client);
 void late_start(int client);
 void boot_complete(int client);
 void magiskhide_handler(int client, ucred *cred);
 void su_daemon_handler(int client, ucred *credential);
+void zygisk_handler(int client, ucred *cred);
 
 // MagiskHide
 void check_enable_hide();

native/jni/zygisk/entry.cpp

@@ -3,9 +3,10 @@
 #include <sys/mount.h>
 #include <sys/sendfile.h>
 #include <sys/prctl.h>
-#include <android/log.h>
 
 #include <utils.hpp>
+#include <daemon.hpp>
+#include <magisk.hpp>
 
 #include "inject.hpp"
 
@@ -14,16 +15,6 @@ using namespace std;
 static void *self_handle = nullptr;
 static atomic<int> active_threads = -1;
 
-#define alog(prio) [](auto fmt, auto ap){ \
-return __android_log_vprint(ANDROID_LOG_##prio, "Magisk", fmt, ap); }
-static void inject_logging() {
-    log_cb.d = alog(DEBUG);
-    log_cb.i = alog(INFO);
-    log_cb.w = alog(WARN);
-    log_cb.e = alog(ERROR);
-    log_cb.ex = nop_ex;
-}
-
 void self_unload() {
     LOGD("hook: Request to self unload\n");
     // If unhook failed, do not unload or else it will cause SIGSEGV
@@ -33,7 +24,7 @@ void self_unload() {
     active_threads--;
 }
 
-static void *unload_first_stage(void *) {
+static void *unload_first_stage(void *v) {
     // Setup 1ms
     timespec ts = { .tv_sec = 0, .tv_nsec = 1000000L };
 
@@ -43,7 +34,8 @@ static void *unload_first_stage(void *) {
     // Wait another 1ms to make sure all threads left our code
     nanosleep(&ts, nullptr);
 
-    unmap_all(INJECT_LIB_1);
+    char *path = static_cast<char *>(v);
+    unmap_all(path);
     active_threads--;
     return nullptr;
 }
@@ -87,66 +79,108 @@ static void inject_cleanup_wait() {
 
 __attribute__((constructor))
 static void inject_init() {
-    if (getenv(INJECT_ENV_2)) {
-        inject_logging();
+    if (char *env = getenv(INJECT_ENV_2)) {
+        android_logging();
         LOGD("zygote: inject 2nd stage\n");
         active_threads = 1;
         unsetenv(INJECT_ENV_2);
 
         // Get our own handle
-        self_handle = dlopen(INJECT_LIB_2, RTLD_LAZY);
+        self_handle = dlopen(env, RTLD_LAZY);
         dlclose(self_handle);
-        unlink(INJECT_LIB_2);
 
         hook_functions();
 
+        // Update path to 1st stage lib
+        *(strrchr(env, '.') - 1) = '1';
+
         // Some cleanup
         sanitize_environ();
         active_threads++;
-        new_daemon_thread(&unload_first_stage);
-    } else if (char *env = getenv(INJECT_ENV_1)) {
-        inject_logging();
+        new_daemon_thread(&unload_first_stage, env);
+    } else if (getenv(INJECT_ENV_1)) {
+        android_logging();
         LOGD("zygote: inject 1st stage\n");
 
-        if (env[0] == '1')
+        char *ld = getenv("LD_PRELOAD");
+        char *path;
+        if (char *c = strrchr(ld, ':')) {
+            *c = '\0';
+            setenv("LD_PRELOAD", ld, 1);  // Restore original LD_PRELOAD
+            path = c + 1;
+        } else {
             unsetenv("LD_PRELOAD");
-        else
-            setenv("LD_PRELOAD", env, 1);  // Restore original LD_PRELOAD
+            path = ld;
+        }
+
+        // Update path to 2nd stage lib
+        *(strrchr(path, '.') - 1) = '2';
 
         // Setup second stage
-        setenv(INJECT_ENV_2, "1", 1);
-        cp_afc(INJECT_LIB_1, INJECT_LIB_2);
-        dlopen(INJECT_LIB_2, RTLD_LAZY);
+        setenv(INJECT_ENV_2, path, 1);
+        dlopen(path, RTLD_LAZY);
 
-        unlink(INJECT_LIB_1);
         unsetenv(INJECT_ENV_1);
     }
 }
 
 int app_process_main(int argc, char *argv[]) {
-    inject_logging();
-    char buf[4096];
-    if (realpath("/proc/self/exe", buf) == nullptr)
-        return 1;
+    android_logging();
 
-    int in = xopen(buf, O_RDONLY);
-    int out = xopen(INJECT_LIB_1, O_WRONLY | O_CREAT, 0644);
-    sendfile(out, in, nullptr, INT_MAX);
-    close(in);
-    close(out);
+    if (int fd = connect_daemon(); fd >= 0) {
+        write_int(fd, ZYGISK_REQUEST);
+        write_int(fd, ZYGISK_SETUP);
 
-    if (char *ld = getenv("LD_PRELOAD")) {
-        char env[128];
-        sprintf(env, "%s:" INJECT_LIB_1, ld);
-        setenv("LD_PRELOAD", env, 1);
-        setenv(INJECT_ENV_1, ld, 1);  // Backup original LD_PRELOAD
-    } else {
-        setenv("LD_PRELOAD", INJECT_LIB_1, 1);
-        setenv(INJECT_ENV_1, "1", 1);
+        if (read_int(fd) == 0) {
+            string path = read_string(fd);
+            string lib = path + ".1.so";
+            if (char *ld = getenv("LD_PRELOAD")) {
+                char env[256];
+                sprintf(env, "%s:%s", ld, lib.data());
+                setenv("LD_PRELOAD", env, 1);
+            } else {
+                setenv("LD_PRELOAD", lib.data(), 1);
+            }
+            setenv(INJECT_ENV_1, "1", 1);
+        }
+        close(fd);
     }
 
     // Execute real app_process
-    xumount2(buf, MNT_DETACH);
+    char buf[256];
+    xreadlink("/proc/self/exe", buf, sizeof(buf));
+    xumount2("/proc/self/exe", MNT_DETACH);
     execve(buf, argv, environ);
     return 1;
 }
+
+// The following code runs in magiskd
+
+static void setup_files(int client, ucred *cred) {
+    LOGD("zygisk: setup files\n");
+
+    char buf[PATH_MAX];
+    sprintf(buf, "/proc/%d/exe", cred->pid);
+    if (realpath(buf, buf) == nullptr) {
+        write_int(client, 1);
+        return;
+    }
+
+    write_int(client, 0);
+
+    string path = MAGISKTMP + "/zygisk." + basename(buf);
+    cp_afc(buf, (path + ".1.so").data());
+    cp_afc(buf, (path + ".2.so").data());
+
+    write_string(client, path);
+}
+
+void zygisk_handler(int client, ucred *cred) {
+    int code = read_int(client);
+    switch (code) {
+    case ZYGISK_SETUP:
+        setup_files(client, cred);
+        break;
+    }
+    close(client);
+}

native/jni/zygisk/inject.hpp

@@ -3,11 +3,13 @@
 #include <stdint.h>
 #include <jni.h>
 
-#define INJECT_LIB_1 "/dev/tmp/magisk.1.so"
-#define INJECT_LIB_2 "/dev/tmp/magisk.2.so"
 #define INJECT_ENV_1 "MAGISK_INJ_1"
 #define INJECT_ENV_2 "MAGISK_INJ_2"
 
+enum : int {
+    ZYGISK_SETUP,
+};
+
 // Unmap all pages matching the name
 void unmap_all(const char *name);
 

scripts/emulator.sh

@@ -23,7 +23,7 @@ abort() {
 
 mount_sbin() {
   mount -t tmpfs -o 'mode=0755' tmpfs /sbin
-  $SELINUX && chcon u:object_r:rootfs:s0 /sbin
+  chcon u:object_r:rootfs:s0 /sbin
 }
 
 if [ ! -f /system/build.prop ]; then
@@ -56,14 +56,14 @@ fi
 pgrep magiskd >/dev/null && pkill -9 magiskd
 [ -f /sbin/magisk ] && umount -l /sbin
 [ -f /system/bin/magisk ] && umount -l /system/bin
+if [ -d /dev/magisk ]; then
+  umount -l /dev/magisk 2>/dev/null
+  rm -rf /dev/magisk
+fi
 
 # SELinux stuffs
-SELINUX=false
-[ -e /sys/fs/selinux ] && SELINUX=true
-if $SELINUX; then
-  ln -sf ./magiskinit magiskpolicy
-  ./magiskpolicy --live --magisk
-fi
+ln -sf ./magiskinit magiskpolicy
+./magiskpolicy --live --magisk
 
 BINDIR=/sbin
 
@@ -99,12 +99,14 @@ elif [ -e /sbin ]; then
   done
 else
   # Android Q+ without sbin, use overlayfs
-  BINDIR=/system/bin
-  rm -rf /dev/magisk
-  mkdir -p /dev/magisk/upper
+  BINDIR=/dev/magisk/upper
+  mkdir /dev/magisk
+  mount -t tmpfs -o 'mode=0755' tmpfs /dev/magisk
+  chcon u:object_r:system_file:s0 /dev/magisk
+  mkdir /dev/magisk/upper
   mkdir /dev/magisk/work
   ./magisk --clone-attr /system/bin /dev/magisk/upper
-  mount -t overlay overlay -olowerdir=/system/bin,upperdir=/dev/magisk/upper,workdir=/dev/magisk/work /system/bin
+  mount -t overlay overlay -o lowerdir=/system/bin,upperdir=/dev/magisk/upper,workdir=/dev/magisk/work /system/bin
 fi
 
 # Magisk stuffs