improve: CLI and code (#3)

This commit improves the CLI of ReZygisk, allowing the use of important information like PID of the daemons. Also improves the code of the loaders ptracer.

loader/src/common/daemon.cpp

@@ -18,10 +18,11 @@ namespace zygiskd {
 
     int Connect(uint8_t retry) {
         int fd = socket(PF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0);
-        struct sockaddr_un addr{
-                .sun_family = AF_UNIX,
-                .sun_path={0},
+        struct sockaddr_un addr = {
+          .sun_family = AF_UNIX,
+          .sun_path = { 0 },
         };
+
         auto socket_path = TMP_PATH + kCPSocketName;
         strcpy(addr.sun_path, socket_path.c_str());
         socklen_t socklen = sizeof(addr);
@@ -67,6 +68,7 @@ namespace zygiskd {
         }
         socket_utils::write_u8(fd, (uint8_t) SocketAction::GetProcessFlags);
         socket_utils::write_u32(fd, uid);
+
         return socket_utils::read_u32(fd);
     }
 
@@ -139,4 +141,29 @@ namespace zygiskd {
             }
         }
     }
+
+    void GetInfo(struct zygote_info *info) {
+      /* TODO: Optimize and avoid re-connect twice here */
+      int fd = Connect(1);
+
+      if (fd != -1) {
+        info->running = true;
+
+        socket_utils::write_u8(fd, (uint8_t) SocketAction::GetInfo);
+
+        int flags = socket_utils::read_u32(fd);
+
+        if (flags & (1 << 29)) {
+          info->root_impl = ZYGOTE_ROOT_IMPL_KERNELSU;
+        } else if (flags & (1 << 30)) {
+          info->root_impl = ZYGOTE_ROOT_IMPL_MAGISK;
+        } else {
+          info->root_impl = ZYGOTE_ROOT_IMPL_NONE;
+        }
+
+        info->pid = socket_utils::read_u32(fd);
+
+        close(fd);
+      } else info->running = false;
+    }
 }

loader/src/include/daemon.h

@@ -42,6 +42,18 @@ class UniqueFd {
     Fd fd_ = -1;
 };
 
+enum zygote_root_impl {
+  ZYGOTE_ROOT_IMPL_NONE,
+  ZYGOTE_ROOT_IMPL_KERNELSU,
+  ZYGOTE_ROOT_IMPL_MAGISK
+};
+
+struct zygote_info {
+  enum zygote_root_impl root_impl;
+  pid_t pid;
+  bool running;
+};
+
 namespace zygiskd {
 
     struct Module {
@@ -55,6 +67,7 @@ namespace zygiskd {
         PingHeartBeat,
         RequestLogcatFd,
         GetProcessFlags,
+        GetInfo,
         ReadModules,
         RequestCompanionSocket,
         GetModuleDir,
@@ -81,4 +94,6 @@ namespace zygiskd {
     void ZygoteRestart();
 
     void SystemServerStarted();
+
+    void GetInfo(struct zygote_info *info);
 }

loader/src/ptracer/main.cpp

@@ -1,12 +1,60 @@
-#include "main.h"
+#include <stdio.h>
+
+#include "monitor.h"
 #include "utils.hpp"
 #include "daemon.h"
 
+#define CUSTOM_TMP_PATH 0
+#define SBIN_AS_TMP_PATH 1
+#define DEBUG_RAMDISK_AS_TMP_PATH 2
+
 int main(int argc, char **argv) {
-  zygiskd::Init(getenv("TMP_PATH"));
+  int tmp_path_type = CUSTOM_TMP_PATH;
+
+  if (getenv("TMP_PATH") == NULL) {
+    tmp_path_type = SBIN_AS_TMP_PATH;
+
+    FILE *fp = fopen("/sbin", "r");
+    if (fp == NULL) {
+      tmp_path_type = DEBUG_RAMDISK_AS_TMP_PATH;
+
+      fp = fopen("/debug_ramdisk", "r");
+
+      if (fp == NULL) {
+        printf("Cannot find TMP_PATH. You should make an issue about that.\n");
+
+        return 1;
+      } else fclose(fp);
+    } else fclose(fp);
+  } else {
+    tmp_path_type = CUSTOM_TMP_PATH;
+  }
+
+  switch (tmp_path_type) {
+    case CUSTOM_TMP_PATH: {
+      zygiskd::Init(getenv("TMP_PATH"));
+
+      break;
+    }
+    case SBIN_AS_TMP_PATH: {
+      zygiskd::Init("/sbin");
+
+      break;
+    }
+    case DEBUG_RAMDISK_AS_TMP_PATH: {
+      zygiskd::Init("/debug_ramdisk");
+
+      break;
+    }
+  }
+
+  printf("The ReZygisk Tracer %s\n\n", ZKSU_VERSION);
+
   if (argc >= 2 && strcmp(argv[1], "monitor") == 0) {
     init_monitor();
 
+    printf("[ReZygisk]: Started monitoring...\n");
+
     return 0;
   } else if (argc >= 3 && strcmp(argv[1], "trace") == 0) {
       if (argc >= 4 && strcmp(argv[3], "--restart") == 0) zygiskd::ZygoteRestart();
@@ -18,35 +66,75 @@ int main(int argc, char **argv) {
         return 1;
       }
 
+      printf("[ReZygisk]: Tracing %ld...\n", pid);
+
       return 0;
   } else if (argc >= 2 && strcmp(argv[1], "ctl") == 0) {
-    if (argc == 3) {
-      if (strcmp(argv[2], "start") == 0) {
-        send_control_command(START);
+    enum Command command;
 
-        return 0;
-      } else if (strcmp(argv[2], "stop") == 0) {
-        send_control_command(STOP);
+    if (strcmp(argv[2], "start") == 0) command = START;
+    else if (strcmp(argv[2], "stop") == 0) command = STOP;
+    else if (strcmp(argv[2], "exit") == 0) command = EXIT;
+    else {
+      printf("[ReZygisk]: Usage: %s ctl <start|stop|exit>\n", argv[0]);
 
-        return 0;
-      } else if (strcmp(argv[2], "exit") == 0) {
-        send_control_command(EXIT);
+      return 1;
+    }
 
-        return 0;
-      }
+    if (send_control_command(command) == -1) {
+      printf("[ReZygisk]: Failed to send the command, is the daemon running?\n");
+
+      return 1;
     }
 
-    printf("ReZygisk Tracer %s\n", ZKSU_VERSION);
-    printf("Usage: %s ctl start|stop|exit\n", argv[0]);
+    printf("[ReZygisk]: command sent\n");
 
-    return 1;
+    return 0;
   } else if (argc >= 2 && strcmp(argv[1], "version") == 0) {
     printf("ReZygisk Tracer %s\n", ZKSU_VERSION);
 
+    return 0;
+  } else if (argc >= 2 && strcmp(argv[1], "info") == 0) {
+    printf("ReZygisk Tracer %s\n", ZKSU_VERSION);
+
+    struct zygote_info info;
+    zygiskd::GetInfo(&info);
+
+    printf("Daemon process PID: %d\n", info.pid);
+
+    switch (info.root_impl) {
+      case ZYGOTE_ROOT_IMPL_NONE: {
+        printf("Root implementation: none\n");
+
+        break;
+      }
+      case ZYGOTE_ROOT_IMPL_KERNELSU: {
+        printf("Root implementation: KernelSU\n");
+
+        break;
+      }
+      case ZYGOTE_ROOT_IMPL_MAGISK: {
+        printf("Root implementation: Magisk\n");
+
+        break;
+      }
+    }
+
+    printf("Is the daemon running: %s\n", info.running ? "yes" : "no");
+
     return 0;
   } else {
     printf("ReZygisk Tracer %s\n", ZKSU_VERSION);
-    printf("usage: %s monitor | trace <pid> | ctl <start|stop|exit> | version\n", argv[0]);
+    printf(
+      "Available commands:\n"
+      " - monitor\n"
+      " - trace <pid> [--restart]\n"
+      " - ctl <start|stop|exit>\n"
+      " - version: Shows the version of ReZygisk.\n"
+      " - info: Shows information about the created daemon/injection.\n"
+      "\n"
+      "<...>: Obligatory\n"
+      "[...]: Optional\n");
 
     return 1;
   }