如何用C++发送自定义ICMP请求

要使用C++发送自定义ICMP请求，您需要使用原始套接字（raw sockets）

#include<iostream>
#include <cstring>
#include <sys/socket.h>
#include <netinet/ip.h>
#include <netinet/ip_icmp.h>
#include <arpa/inet.h>
#include <unistd.h>

const int ICMP_PACKET_SIZE = 64;

void createIcmpHeader(icmphdr &icmpHeader, int type, int code) {
    icmpHeader.type = type;
    icmpHeader.code = code;
    icmpHeader.checksum = 0;
}

uint16_t calculateChecksum(icmphdr &icmpHeader) {
    uint32_t sum = 0;
    uint16_t *buf = (uint16_t *)&icmpHeader;
    uint16_t size = sizeof(icmpHeader);

    while (size > 1) {
        sum += *(buf++);
        size -= 2;
    }

    if (size) {
        sum += *(uint8_t *)buf;
    }

    while (sum >> 16) {
        sum = (sum & 0xffff) + (sum >> 16);
    }

    return (uint16_t)(~sum);
}

int main() {
    int rawSocket;
    struct sockaddr_in targetAddress;
    char datagram[ICMP_PACKET_SIZE];

    // 创建原始套接字
    if ((rawSocket = socket(AF_INET, SOCK_RAW, IPPROTO_ICMP)) == -1) {
        std::cerr << "Failed to create raw socket"<< std::endl;
        return 1;
    }

    // 设置目标地址
    targetAddress.sin_family = AF_INET;
    targetAddress.sin_addr.s_addr = inet_addr("8.8.8.8"); // 更改为您想要发送ICMP请求的IP地址

    // 创建ICMP头部
    icmphdr *icmpHeader = (icmphdr *)datagram;
    createIcmpHeader(*icmpHeader, ICMP_ECHO, 0);

    // 计算校验和
    icmpHeader->checksum = calculateChecksum(*icmpHeader);

    // 发送ICMP请求
    if (sendto(rawSocket, datagram, ICMP_PACKET_SIZE, 0, (struct sockaddr *)&targetAddress, sizeof(targetAddress)) <= 0) {
        std::cerr << "Failed to send ICMP request"<< std::endl;
        return 1;
    }

    std::cout << "ICMP request sent successfully!"<< std::endl;

    close(rawSocket);
    return 0;
}

这个示例代码创建了一个原始套接字，然后构建并发送一个ICMP回显请求（ping请求）。请注意，运行此代码可能需要root权限。在运行之前，请确保将目标IP地址更改为您想要发送ICMP请求的IP地址。

在Linux上编译和运行此代码：

g++ -o icmp_request icmp_request.cpp
sudo ./icmp_request

此代码仅作为示例，实际应用中可能需要根据需求进行修改。