Integrate MagiskHide into Magisk Daemon

jni/magiskhide/hide_daemon.c

@@ -18,7 +18,7 @@
 #include "utils.h"
 #include "magiskhide.h"
 
-static int isMocked = 0;
+static int isMocked = 0, pid;
 
 static void manage_selinux() {
 	if (isMocked) return;
@@ -43,23 +43,36 @@ static void lazy_unmount(const char* mountpoint) {
 		LOGI("hide_daemon: Unmount Failed (%s)\n", mountpoint);
 }
 
-void hide_daemon() {
+static void hide_daemon_err() {
+	LOGD("hide_daemon: error occured, stopping magiskhide services\n");
+	// Resume process if possible
+	kill(pid, SIGCONT);
+	int err = 1;
+	write(sv[1], &err, sizeof(err));
+	_exit(-1);
+}
+
+int hide_daemon() {
 	// Fork to a new process
-	switch(fork()) {
+	hide_pid = fork();
+	switch(hide_pid) {
 	case -1:
 		PLOGE("fork");
+		return 1;
 	case 0:
 		break;
 	default:
-		return;
+		return 0;
 	}
 
-	close(pipefd[1]);
+	close(sv[0]);
 
 	// Set the process name
 	strcpy(argv0, "magiskhide_daemon");
+	// When an error occurs, report its failure to main process
+	err_handler = hide_daemon_err;
 	
-	int pid, fd;
+	int fd;
 	FILE *fp;
 	char cache_block[256], *line;
 	struct vector mount_list;
@@ -67,9 +80,12 @@ void hide_daemon() {
 	cache_block[0] = '\0';
 
 	while(1) {
-		xxread(pipefd[0], &pid, sizeof(pid));
+		xxread(sv[1], &pid, sizeof(pid));
 		// Termination called
-		if(pid == -1) exit(0);
+		if(pid == -1) {
+			LOGD("hide_daemon: received termination request\n");
+			_exit(0);
+		}
 
 		snprintf(magiskbuf, BUF_SIZE, "/proc/%d/ns/mnt", pid);
 		if(access(magiskbuf, F_OK) == -1) continue; // Maybe process died..
@@ -95,7 +111,7 @@ void hide_daemon() {
 				}
 			}
 		}
-		
+
 		// First unmount the dummy skeletons, cache mounts, and /sbin links
 		vec_for_each_r(&mount_list, line) {
 			if (strstr(line, "tmpfs /system") || strstr(line, "tmpfs /vendor") || strstr(line, "tmpfs /sbin")
@@ -125,6 +141,10 @@ void hide_daemon() {
 
 		// All done, send resume signal
 		kill(pid, SIGCONT);
+
+		// Tell main process all is well
+		pid = 0;
+		xwrite(sv[1], &pid, sizeof(pid));
 	}
 
 	// Should never go here

jni/magiskhide/magiskhide.c

@@ -8,38 +8,67 @@
 #include <unistd.h>
 #include <pthread.h>
 #include <signal.h>
+#include <string.h>
+#include <sys/wait.h>
 #include <sys/types.h>
 
 #include "magisk.h"
 #include "utils.h"
 #include "magiskhide.h"
+#include "daemon.h"
 
-int pipefd[2];
+int sv[2], hide_pid;
 struct vector *hide_list, *new_list;
 
+int isEnabled = 0;
 static pthread_t proc_monitor_thread;
 
-static void kill_proc(int pid) {
+void kill_proc(int pid) {
 	kill(pid, SIGTERM);
 }
 
-void launch_magiskhide() {
+static void usage(char *arg0) {
+	fprintf(stderr,
+		"%s [--options [arguments...] ]\n\n"
+		"Options:\n"
+		"  --enable: Start the magiskhide daemon\n"
+		"  --disable: Stop the magiskhide daemon\n"
+		"  --add <process name>: Add <process name> to the list\n"
+		"  --rm <process name>: Remove <process name> from the list\n"
+		"  --ls: Print out the current hide list\n"
+		, arg0);
+	exit(1);
+}
+
+void launch_magiskhide(int client) {
+	if (isEnabled) {
+		write_int(client, 0);
+		return;
+	}
 	/*
 	 * The setns system call do not support multithread processes
 	 * We have to fork a new process, and communicate with pipe
 	 */
 
-	xpipe(pipefd);
+	LOGI("* Starting MagiskHide\n");
+
+	if (socketpair(AF_LOCAL, SOCK_STREAM, 0, sv) == -1)
+		goto error;
 
 	// Launch the hide daemon
-	hide_daemon();
+	if (hide_daemon())
+		goto error;
 
-	close(pipefd[0]);
+	close(sv[1]);
 
 	// Initialize the hide list
-	hide_list = new_list = malloc(sizeof(*hide_list));
+	hide_list = new_list = xmalloc(sizeof(*hide_list));
+	if (hide_list == NULL)
+		goto error;
 	vec_init(hide_list);
 	FILE *fp = xfopen(HIDELIST, "r");
+	if (fp == NULL)
+		goto error;
 	file_to_vector(hide_list, fp);
 	fclose(fp);
 	char *line;
@@ -49,20 +78,66 @@ void launch_magiskhide() {
 	}
 
 	// Start a new thread to monitor processes
-	pthread_create(&proc_monitor_thread, NULL, proc_monitor, NULL);
-	pthread_join(proc_monitor_thread, NULL);
+	if (xpthread_create(&proc_monitor_thread, NULL, proc_monitor, NULL))
+		goto error;
+
+	isEnabled = 1;
+	write_int(client, 0);
+	return;
+error:
+	write_int(client, 1);
+	return;
 }
 
-void stop_magiskhide() {
+void stop_magiskhide(int client) {
+	if (!isEnabled)
+		return;
+
+	LOGI("* Stopping MagiskHide\n");
+
 	int kill = -1;
 	// Terminate hide daemon
-	xwrite(pipefd[1], &kill, sizeof(kill));
+	write(sv[0], &kill, sizeof(kill));
+	close(sv[0]);
+	waitpid(hide_pid, NULL, 0);
 	// Stop process monitor
 	pthread_kill(proc_monitor_thread, SIGUSR1);
 	pthread_join(proc_monitor_thread, NULL);
+
+	isEnabled = 0;
+	write_int(client, 0);
 }
 
 int magiskhide_main(int argc, char *argv[]) {
-	launch_magiskhide();
-	return 0;
+	if (argc < 2) {
+		usage(argv[0]);
+	}
+	client_request req;
+	if (strcmp(argv[1], "--enable") == 0) {
+		req = LAUNCH_MAGISKHIDE;
+	} else if (strcmp(argv[1], "--disable") == 0) {
+		req = STOP_MAGISKHIDE;
+	} else if (strcmp(argv[1], "--add") == 0 && argc > 2) {
+		req = ADD_HIDELIST;
+	} else if (strcmp(argv[1], "--rm") == 0 && argc > 2) {
+		req = RM_HIDELIST;
+	} else if (strcmp(argv[1], "--ls") == 0) {
+		FILE *fp = xfopen(HIDELIST, "r");
+		while (fgets(magiskbuf, BUF_SIZE, fp)) {
+			printf("%s", magiskbuf);
+		}
+		fclose(fp);
+		return 0;
+	}
+	int fd = connect_daemon();
+	write_int(fd, req);
+	if (req == ADD_HIDELIST || req == RM_HIDELIST) {
+		write_string(fd, argv[2]);
+	}
+	int code = read_int(fd);
+	close(fd);
+	if (code) {
+		fprintf(stderr, "Error occured in MagiskHide daemon\n");
+	}
+	return code;
 }

jni/magiskhide/magiskhide.h

@@ -6,13 +6,16 @@
 #define ENFORCE_FILE 	"/sys/fs/selinux/enforce"
 #define POLICY_FILE 	"/sys/fs/selinux/policy"
 
+// Kill process
+void kill_proc(int pid);
+
 // Hide daemon
-void hide_daemon();
+int hide_daemon();
 
 // Process monitor
 void *proc_monitor(void *args);
 
-extern int pipefd[2];
+extern int sv[2], hide_pid, isEnabled;
 extern struct vector *hide_list, *new_list;
 
 #endif

jni/magiskhide/proc_monitor.c

@@ -11,15 +11,12 @@
 #include <signal.h>
 #include <pthread.h>
 #include <sys/types.h>
+#include <sys/wait.h>
 
 #include "magisk.h"
 #include "utils.h"
 #include "magiskhide.h"
 
-/* WTF... the macro in the NDK pthread.h is broken.... */
-#define pthread_cleanup_push_fix(routine, arg)  \
-pthread_cleanup_push(routine, arg) } while(0);
-
 static int zygote_num = 0;
 static char init_ns[32], zygote_ns[2][32];
 
@@ -32,15 +29,21 @@ static void read_namespace(const int pid, char* target, const size_t size) {
 
 // Workaround for the lack of pthread_cancel
 static void quit_pthread(int sig) {
-	pthread_exit(NULL);
-}
-
-static void cleanup_handler(void *arg) {
+	LOGD("proc_monitor: running cleanup\n");
+	char *line;
+	vec_for_each(hide_list, line) {
+		ps_filter_proc_name(line, kill_proc);
+	}
 	vec_deep_destroy(hide_list);
-	vec_deep_destroy(new_list);
 	free(hide_list);
-	free(new_list);
+	if (new_list != hide_list) {
+		vec_deep_destroy(new_list);
+		free(new_list);
+	}
 	hide_list = new_list = NULL;
+	isEnabled = 0;
+	LOGD("proc_monitor: terminating...\n");
+	pthread_exit(NULL);
 }
 
 static void store_zygote_ns(int pid) {
@@ -51,10 +54,21 @@ static void store_zygote_ns(int pid) {
 	++zygote_num;
 }
 
+static void proc_monitor_err() {
+	LOGD("proc_monitor: error occured, stopping magiskhide services\n");
+	int kill = -1;
+	// If process monitor dies, kill hide daemon too
+	write(sv[0], &kill, sizeof(kill));
+	close(sv[0]);
+	waitpid(hide_pid, NULL, 0);
+	quit_pthread(SIGUSR1);
+}
+
 void *proc_monitor(void *args) {
 	// Register the cancel signal
 	signal(SIGUSR1, quit_pthread);
-	pthread_cleanup_push_fix(cleanup_handler, NULL);
+	// The error handler should only exit the thread, not the whole process
+	err_handler = proc_monitor_err;
 
 	int pid;
 	char buffer[512];
@@ -106,6 +120,8 @@ void *proc_monitor(void *args) {
 			hide_list = new_list;
 		}
 
+		ret = 0;
+
 		vec_for_each(hide_list, line) {
 			if (strcmp(processName, line) == 0) {
 				read_namespace(pid, buffer, 32);
@@ -121,13 +137,19 @@ void *proc_monitor(void *args) {
 					if (ret) break;
 				}
 
+				ret = 0;
+
 				// Send pause signal ASAP
 				if (kill(pid, SIGSTOP) == -1) continue;
 
 				LOGI("proc_monitor: %s(PID=%d ns=%s)\n", processName, pid, buffer);
 
 				// Unmount start
-				xwrite(pipefd[1], &pid, sizeof(pid));
+				xwrite(sv[0], &pid, sizeof(pid));
+
+				// Get the hide daemon return code
+				xxread(sv[0], &ret, sizeof(ret));
+				LOGD("proc_monitor: hide daemon response code: %d\n", ret);
 				break;
 			}
 		}
@@ -135,10 +157,15 @@ void *proc_monitor(void *args) {
 			vec_deep_destroy(temp);
 			free(temp);
 		}
+		if (ret) {
+			// Wait hide process to kill itself
+			waitpid(hide_pid, NULL, 0);
+			quit_pthread(SIGUSR1);
+		}
 	}
 
 	// Should never be here
 	pclose(p);
-	quit_pthread(SIGUSR1);
+	pthread_exit(NULL);
 	return NULL;
 }