编程实现traceroute

traceroute 是一种网络诊断工具，用于确定数据包从源主机到目标主机的路径。在编程实现 traceroute 时，可以使用套接字编程来发送 ICMP 数据包，并通过设置不同的 TTL（生存时间）值来检测路由器的跳数。以下是一个简单的 Python 示例代码来实现 traceroute。

import socket
import struct
import sys
import time

def traceroute(destination):
    destination_ip = socket.gethostbyname(destination)
    max_hops = 30
    port = 33434

    icmp = socket.getprotobyname('icmp')
    udp = socket.getprotobyname('udp')

    ttl = 1
    while True:
        receiver_socket = socket.socket(socket.AF_INET, socket.SOCK_RAW, icmp)
        sender_socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, udp)
        sender_socket.setsockopt(socket.SOL_IP, socket.IP_TTL, ttl)

        receiver_socket.bind(("", port))
        sender_socket.sendto(b"", (destination, port))
        start_time = time.time()

        try:
            _, address = receiver_socket.recvfrom(1024)
            end_time = time.time()
            elapsed_time = round((end_time - start_time) * 1000, 2)
            host_ip = address[0]
            host_name = socket.gethostbyaddr(host_ip)[0]

            print(f"{ttl}\t{host_ip}\t{host_name}\t{elapsed_time} ms")
            
            if host_ip == destination_ip or ttl >= max_hops:
                break

        except socket.error:
            print(f"{ttl}\t*\t*\t*")

        finally:
            receiver_socket.close()
            sender_socket.close()

        ttl += 1

    print("Traceroute completed.")

traceroute("example.com")