android app 执行shell脚本route add 时提示“route: SIOCADDRT: Operation not permitted”

博主，你好！有个问题请教一下。我从android app上执行route add指令时提示“route: SIOCADDRT: Operation not permitted”这个错误,app已获取root权限，且该命令通过adb shell可以执行成功，但是在这个APP 里执行这个shell命令就报这个错误,app执行“busybox route -n”可以成功。请问这是为什么呢？求指教！具体代码如下：

public static void addRoute(String dst,String mask,String nextjump){
        String dstIP = dst.substring(0,dst.lastIndexOf("."));
        String command = "su -c busybox route add -net "+dstIP+".0 netmask "+mask+" gw "+nextjump+" dev eth0";
        CommandResult rs = shellCommand(command, true);
    }

public static CommandResult shellCommand(String[] commands, boolean isRoot) {
        CommandResult commandResult = new CommandResult();
        if (commands == null || commands.length == 0) return commandResult;
        Process process = null;
        DataOutputStream os = null;
        BufferedReader successResult = null;
        BufferedReader errorResult = null;
        StringBuilder successMsg = null;
        StringBuilder errorMsg = null;
        try {
            process = Runtime.getRuntime().exec(isRoot ? COMMAND_SU : COMMAND_SH);
            os = new DataOutputStream(process.getOutputStream());
            for (String command : commands) {
                if (command != null) {
                    os.write(command.getBytes());
                    os.writeBytes(COMMAND_LINE_END);
                    os.flush();
                }
            }
            os.writeBytes(COMMAND_EXIT);
            os.flush();
            commandResult.result = process.waitFor();
            //获取错误信息
            successMsg = new StringBuilder();
            errorMsg = new StringBuilder();
            successResult = new BufferedReader(new InputStreamReader(process.getInputStream()));
            errorResult = new BufferedReader(new InputStreamReader(process.getErrorStream()));
            String s;
            while ((s = successResult.readLine()) != null) successMsg.append(s);
            while ((s = errorResult.readLine()) != null) errorMsg.append(s);
            commandResult.successMsg = successMsg.toString();
            commandResult.errorMsg = errorMsg.toString();
            Log.i(TAG, commandResult.result + " | " + commandResult.successMsg
                    + " | " + commandResult.errorMsg);
        } catch (IOException e) {
            String errmsg = e.getMessage();
            if (errmsg != null) {
                Log.e(TAG, errmsg);
            } else {
                e.printStackTrace();
            }
        } catch (Exception e) {
            String errmsg = e.getMessage();
            if (errmsg != null) {
                Log.e(TAG, errmsg);
            } else {
                e.printStackTrace();
            }
        } finally {
            try {
                if (os != null) os.close();
                if (successResult != null) successResult.close();
                if (errorResult != null) errorResult.close();
            } catch (IOException e) {
                String errmsg = e.getMessage();
                if (errmsg != null) {
                    Log.e(TAG, errmsg);
                } else {
                    e.printStackTrace();
                }
            }
            if (process != null) process.destroy();
        }
        return commandResult;
    }