Hook up denylist IPC routines

native/jni/magiskhide/hide_policy.cpp

@@ -14,11 +14,10 @@ static void lazy_unmount(const char* mountpoint) {
         LOGD("hide: Unmounted (%s)\n", mountpoint);
 }
 
-void hide_daemon(int pid) {
+void hide_daemon(int pid, int client) {
     if (fork_dont_care() == 0) {
         hide_unmount(pid);
-        // Send resume signal
-        kill(pid, SIGCONT);
+        write_int(client, 0);
         _exit(0);
     }
 }
@@ -29,7 +28,7 @@ void hide_unmount(int pid) {
     if (pid > 0 && switch_mnt_ns(pid))
         return;
 
-    LOGD("hide: handling PID=[%d]\n", pid);
+    LOGD("hide: handling PID=[%d]\n", pid > 0 ? pid : getpid());
 
     vector<string> targets;
 

native/jni/magiskhide/magiskhide.hpp

@@ -21,7 +21,7 @@ bool hide_enabled();
 bool is_hide_target(int uid, std::string_view process);
 
 // Hide policies
-void hide_daemon(int pid);
+void hide_daemon(int pid, int client);
 void hide_unmount(int pid = -1);
 
 enum {

native/jni/zygisk/entry.cpp

@@ -9,6 +9,7 @@
 #include <magisk.hpp>
 
 #include "inject.hpp"
+#include "../magiskhide/magiskhide.hpp"
 
 using namespace std;
 
@@ -124,6 +125,8 @@ static void inject_init() {
     }
 }
 
+// Start code for magiskd IPC
+
 int app_process_main(int argc, char *argv[]) {
     android_logging();
 
@@ -154,6 +157,34 @@ int app_process_main(int argc, char *argv[]) {
     return 1;
 }
 
+bool remote_check_denylist(int uid, const char *process) {
+    if (int fd = connect_daemon(); fd >= 0) {
+        write_int(fd, ZYGISK_REQUEST);
+        write_int(fd, ZYGISK_CHECK_DENYLIST);
+
+        int ret = -1;
+        if (read_int(fd) == 0) {
+            write_int(fd, uid);
+            write_string(fd, process);
+            ret = read_int(fd);
+        }
+        close(fd);
+        return ret >= 0 && ret;
+    }
+    return false;
+}
+
+int remote_request_unmount() {
+    if (int fd = connect_daemon(); fd >= 0) {
+        write_int(fd, ZYGISK_REQUEST);
+        write_int(fd, ZYGISK_UNMOUNT);
+        int ret = read_int(fd);
+        close(fd);
+        return ret;
+    }
+    return DAEMON_ERROR;
+}
+
 // The following code runs in magiskd
 
 static void setup_files(int client, ucred *cred) {
@@ -175,12 +206,38 @@ static void setup_files(int client, ucred *cred) {
     write_string(client, path);
 }
 
+static void check_denylist(int client) {
+    if (!hide_enabled()) {
+        write_int(client, HIDE_NOT_ENABLED);
+        return;
+    }
+    write_int(client, 0);
+    int uid = read_int(client);
+    string process = read_string(client);
+    write_int(client, is_hide_target(uid, process));
+}
+
+static void do_unmount(int client, ucred *cred) {
+    LOGD("zygisk: cleanup mount namespace for pid=[%d]\n", cred->pid);
+    if (hide_enabled()) {
+        hide_daemon(cred->pid, client);
+    } else {
+        write_int(client, HIDE_NOT_ENABLED);
+    }
+}
+
 void zygisk_handler(int client, ucred *cred) {
     int code = read_int(client);
     switch (code) {
     case ZYGISK_SETUP:
         setup_files(client, cred);
         break;
+    case ZYGISK_CHECK_DENYLIST:
+        check_denylist(client);
+        break;
+    case ZYGISK_UNMOUNT:
+        do_unmount(client, cred);
+        break;
     }
     close(client);
 }

native/jni/zygisk/hook.cpp

@@ -129,12 +129,6 @@ string get_class_name(JNIEnv *env, jclass clazz) {
 
 // -----------------------------------------------------------------
 
-// TODO
-int remote_check_denylist(int uid, const char *process) { return 0; }
-void remote_request_unmount() {}
-
-// -----------------------------------------------------------------
-
 #define DCL_HOOK_FUNC(ret, func, ...) \
 ret (*old_##func)(__VA_ARGS__);       \
 ret new_##func(__VA_ARGS__)
@@ -161,10 +155,11 @@ DCL_HOOK_FUNC(int, fork) {
 DCL_HOOK_FUNC(int, selinux_android_setcontext,
         uid_t uid, int isSystemServer, const char *seinfo, const char *pkgname) {
     if (g_ctx && g_ctx->flags[DENY_FLAG]) {
-        // Ask magiskd to cleanup the mount namespace before switching context
+        // Ask magiskd to cleanup our mount namespace before switching context
         // This is the latest point where we can still connect to the magiskd main socket
-        remote_request_unmount();
-        LOGD("zygisk: process successfully hidden\n");
+        if (remote_request_unmount() == 0) {
+            LOGD("zygisk: mount namespace cleaned up\n");
+        }
     }
     return old_selinux_android_setcontext(uid, isSystemServer, seinfo, pkgname);
 }

native/jni/zygisk/inject.hpp

@@ -8,6 +8,8 @@
 
 enum : int {
     ZYGISK_SETUP,
+    ZYGISK_CHECK_DENYLIST,
+    ZYGISK_UNMOUNT,
 };
 
 // Unmap all pages matching the name
@@ -22,3 +24,5 @@ uintptr_t get_function_addr(int pid, const char *lib, uintptr_t off);
 void self_unload();
 void hook_functions();
 bool unhook_functions();
+bool remote_check_denylist(int uid, const char *process);
+int remote_request_unmount();