写一份发起dns查询的代码

以下是 Python 代码示例，用于发起 DNS 查询：

import socket

def query_dns(hostname):
    try:
        result = socket.gethostbyname(hostname)
        print(f"The IP addresses for {hostname} are: {result}")
    except socket.gaierror:
        print(f"Failed to resolve {hostname}")

你可以通过调用 `query_dns('example.com')` 来查询 example.com 的 IP 地址。如果查询成功，它将返回一个包含 IP 地址的列表，否则将返回错误消息。

相关问题

用java来写一份发起dns查询的代码

当然，我可以帮您写一份Java代码来发起DNS查询。您可以使用Java中的InetAddress类来发起DNS查询。以下是Java代码示例，您可以通过将域名替换为您想要查询的域名并运行此代码来进行发起DNS查询。

import java.net.InetAddress;
import java.net.UnknownHostException;

public class DNSQuery {

    public static void main(String[] args) {
        try {
            InetAddress address = InetAddress.getByName("www.example.com");
            System.out.println("IP address: " + address.getHostAddress());
        } catch (UnknownHostException e) {
            System.out.println("Unable to find IP address for specified hostname");
        }
    }
}

希望这可以帮助您！

用linux c写dns报文查询代码

下面是一个简单的 DNS 查询代码，使用 C 语言在 Linux 上编写：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>

#define DNS_QUERY_PORT 53
#define DNS_SERVER_IP "8.8.8.8"
#define DNS_QUERY_NAME "www.google.com"

struct DNS_HEADER
{
    unsigned short id;
    unsigned char rd :1;
    unsigned char tc :1;
    unsigned char aa :1;
    unsigned char opcode :4;
    unsigned char qr :1;

    unsigned char rcode :4;
    unsigned char cd :1;
    unsigned char ad :1;
    unsigned char z :1;
    unsigned char ra :1;

    unsigned short q_count;
    unsigned short ans_count;
    unsigned short auth_count;
    unsigned short add_count;
};

struct QUESTION
{
    unsigned short qtype;
    unsigned short qclass;
};

int main(int argc, char *argv[])
{
    int sockfd;
    struct sockaddr_in serv_addr;
    char send_buf[1024];
    char recv_buf[1024];
    int send_len;
    int recv_len;

    // 创建套接字
    if ((sockfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0)
    {
        perror("socket error");
        exit(EXIT_FAILURE);
    }

    memset(&serv_addr, 0, sizeof(serv_addr));
    serv_addr.sin_family = AF_INET;
    serv_addr.sin_port = htons(DNS_QUERY_PORT);
    serv_addr.sin_addr.s_addr = inet_addr(DNS_SERVER_IP);

    struct DNS_HEADER *dns = (struct DNS_HEADER *)send_buf;
    struct QUESTION *qinfo = (struct QUESTION *)(send_buf + sizeof(struct DNS_HEADER));

    dns->id = (unsigned short)htons(getpid());
    dns->qr = 0;
    dns->opcode = 0;
    dns->aa = 0;
    dns->tc = 0;
    dns->rd = 1;
    dns->ra = 0;
    dns->z = 0;
    dns->ad = 0;
    dns->cd = 0;
    dns->rcode = 0;
    dns->q_count = htons(1);
    dns->ans_count = 0;
    dns->auth_count = 0;
    dns->add_count = 0;

    qinfo->qtype = htons(1);