android调用C语言实现内存的读取与修改的方法示例

写之前需要准备以下内容

android studio
已ROOT安卓设备
GG修改器

打开android studio,创建Native C++ Project

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:gravity="center"
  android:orientation="vertical">

  <Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:onClick="btn" />

  <TextView
    android:id="@+id/tv"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="~" />

</LinearLayout>

MainActivity.java

package com.gs.jc;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.View;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {

  private TextView textView;
  private JNI jni;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    jni = new JNI();
    textView = (TextView) findViewById(R.id.tv);
  }

  public void btn(View view) {
    textView.setText(String.valueOf(jni.searchMem()));
  }

}

新建一个java类,以实现java调用对应C代码

package com.gs.jc;

public class JNI {

  static {
    System.loadLibrary("native-lib");
  }

	/*
	*定义native方法
	*调用C代码对应的方法
	*/
  public native int searchMem();
}

O_RDONLY只读打开
O_WRONLY只写打开
O_RDWR可读可写打开
O_SYNC以同步的方式打开文件

C++核心代码

#include <jni.h>
#include <string>
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <dirent.h>
#include <unistd.h>

static int fd = 0;

//查找游戏进程pid
int getPID(const char *pack_name) {
  int id = -1, pid = -1;
  DIR *dir = 0;
  FILE *file = 0;
  char filename[32] = {0};
  char cmdline[256] = {0};
  struct dirent *entry = 0;

  if (pack_name == NULL) {
    return -1;
  }

  dir = opendir("/proc");
  if (dir == NULL) {
    return -1;
  }

  while ((entry = readdir(dir)) != NULL) {
    id = atoi(entry->d_name);
    if (id > 0) {
      sprintf(filename, "/proc/%d/cmdline", id);
      file = fopen(filename, "r");

      if (file) {
        fgets(cmdline, sizeof(cmdline), file);
        fclose(file);

        if (strcmp(pack_name, cmdline) == 0) {
          pid = id;
          break;
        }
      }
    }
  }
  closedir(dir);
  return pid;
}

//打开文件句柄
int open_proc_mem(int pid) {

  if (pid <= 0)
    return -1;

  char mempath[64] = {0};
  int handle = -1;
  sprintf(mempath, "/proc/%d/mem", pid);

  handle = open(mempath, O_RDWR, O_SYNC);

  return handle;
}

//读内存
void pread64_mem(int fd, void *buff, int size, long *addr) {
  if (fd <= 0 || buff == NULL || size <= 0 || addr == NULL)
    return;
  pread64(fd, buff, size, (unsigned long) addr);
}

//写内存
void pwrite64_mem(int fd, const void *buff, int size, long *addr) {
  if (fd <= 0 || buff == NULL || size <= 0 || addr == NULL)
    return;
  pwrite64(fd, buff, size, (unsigned long) addr);
}

extern "C"
jint Java_com_gs_jc_JNI_searchMem(JNIEnv *env, jobject thiz) {
  char *game = "com.tencent.tmgp.sgame"; //包名

  int pid = getPID(game);		//获取进程PID
  fd = open_proc_mem(pid);	//打开进程内存

  //long base = 0;
  long buf[1] = {666};				//需要修改内存的值
  long *addr = (long *) 0x12C0085C;	//内存地址:0x12C0085C
  pwrite64_mem(fd, &buf[0], 4, addr);	//写入内存数据
  //pread64_mem(fd, &base, 4, addr);

  return pid;
}

C代码中需要自行修改的地方

char *game = “com.tencent.tmgp.sgame”; //包名
long *addr = (long *) 0x12C0085C;//内存地址

效果图链接:yuanma/men_jb51.rar

以上是简单的内存地址修改方法，到此这篇关于android调用C语言实现内存的读取与修改的方法示例的文章就介绍到这了,更多相关android调用C语言实现内存读取修改内容请搜索我们以前的文章或继续浏览下面的相关文章希望大家以后多多支持我们！