如何在android上进行icmp ping

Question

我需要从我的 android 设备对主机进行 icmp ping。我需要测量往返时间。我精通android和java，只是不知道使用什么库。 我该怎么做？ 通过 3G、Edge 可以吗？

Answer 1

是的，只要您有连接，您就可以使用 3G、边缘、无线等方式 ping。唯一的限制是在模拟器中，请参见此处： http://groups.google.com/group/android-developers/browse_thread/thread/8657506be6819297

这是我的 ping 功能：

package com.namespace.router.api;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

import android.util.Log;

public class Network {

    private static final String TAG = "Network.java";   

    public static String pingError = null;

    /**
     * Ping a host and return an int value of 0 or 1 or 2 0=success, 1=fail, 2=error
     * 
     * Does not work in Android emulator and also delay by '1' second if host not pingable
     * In the Android emulator only ping to 127.0.0.1 works
     * 
     * @param String host in dotted IP address format
     * @return
     * @throws IOException
     * @throws InterruptedException
     */
    public static int pingHost(String host) throws IOException, InterruptedException {
        Runtime runtime = Runtime.getRuntime();
        Process proc = runtime.exec("ping -c 1 " + host);
        proc.waitFor();     
        int exit = proc.exitValue();
        return exit;
    }

    public static String ping(String host) throws IOException, InterruptedException {
        StringBuffer echo = new StringBuffer();
        Runtime runtime = Runtime.getRuntime();
        Log.v(TAG, "About to ping using runtime.exec");
        Process proc = runtime.exec("ping -c 1 " + host);
        proc.waitFor();
        int exit = proc.exitValue();
        if (exit == 0) {
            InputStreamReader reader = new InputStreamReader(proc.getInputStream());
            BufferedReader buffer = new BufferedReader(reader);
            String line = "";
            while ((line = buffer.readLine()) != null) {
                echo.append(line + "\n");
            }           
            return getPingStats(echo.toString());   
        } else if (exit == 1) {
            pingError = "failed, exit = 1";
            return null;            
        } else {
            pingError = "error, exit = 2";
            return null;    
        }       
    }

    /**
     * getPingStats interprets the text result of a Linux ping command
     * 
     * Set pingError on error and return null
     * 
     * http://en.wikipedia.org/wiki/Ping
     * 
     * PING 127.0.0.1 (127.0.0.1) 56(84) bytes of data.
     * 64 bytes from 127.0.0.1: icmp_seq=1 ttl=64 time=0.251 ms
     * 64 bytes from 127.0.0.1: icmp_seq=2 ttl=64 time=0.294 ms
     * 64 bytes from 127.0.0.1: icmp_seq=3 ttl=64 time=0.295 ms
     * 64 bytes from 127.0.0.1: icmp_seq=4 ttl=64 time=0.300 ms
     *
     * --- 127.0.0.1 ping statistics ---
     * 4 packets transmitted, 4 received, 0% packet loss, time 0ms
     * rtt min/avg/max/mdev = 0.251/0.285/0.300/0.019 ms
     * 
     * PING 192.168.0.2 (192.168.0.2) 56(84) bytes of data.
     * 
     * --- 192.168.0.2 ping statistics ---
     * 1 packets transmitted, 0 received, 100% packet loss, time 0ms
     *
     * # ping 321321.
     * ping: unknown host 321321.
     * 
     * 1. Check if output contains 0% packet loss : Branch to success -> Get stats
     * 2. Check if output contains 100% packet loss : Branch to fail -> No stats
     * 3. Check if output contains 25% packet loss : Branch to partial success -> Get stats
     * 4. Check if output contains "unknown host"
     * 
     * @param s
     */
    public static String getPingStats(String s) {
        if (s.contains("0% packet loss")) {
            int start = s.indexOf("/mdev = ");
            int end = s.indexOf(" ms\n", start);
            s = s.substring(start + 8, end);            
            String stats[] = s.split("/");
            return stats[2];
        } else if (s.contains("100% packet loss")) {
            pingError = "100% packet loss";
            return null;            
        } else if (s.contains("% packet loss")) {
            pingError = "partial packet loss";
            return null;
        } else if (s.contains("unknown host")) {
            pingError = "unknown host";
            return null;
        } else {
            pingError = "unknown error in getPingStats";
            return null;
        }       
    }
}

Answer 2

您可能想要使用isReachable - 请参阅Android doc 中的更多详细信息。但是，显然某些网络会阻止 ICMP。有一个帖子，您可以在其中阅读有关此问题的更多信息here。

Answer 3

可以使用终端模拟器的开源代码here

构建库（使用cygwin和android-ndk）文件然后使用

Answer 4

从 socket(2) 手册页中，设备中的 ping 访问受到 /proc/sys/net/ipv4/ping_group_range 文件内容的限制

$ cat /proc/sys/net/ipv4/ping_group_range

默认为“1 0”，意思是 没有人（甚至不是 root）可以创建 ping 套接字。设置为“100 100" 将授予单个组的权限（使 /sbin/ping g+s 并由该组拥有或授予权限 "netadmins" 组), "0 4294967295" 将为全世界启用它, "100 4294967295" 将为用户启用它，但不为守护进程启用。

所以除“0 4294967295”以外的任何设备都无法从 android java 应用程序访问

在模拟器中你可以测试这个是重置

sysctl -w net.ipv4.ping_group_range="0 0" // 到某个范围