linux c语言原始套接字

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

#define DEST_IP "192.168.1.1"
#define DEST_PORT 80

int main() {
    int sockfd;
    struct sockaddr_in dest_addr;
    char packet[2048];

    // 创建原始套接字
    if ((sockfd = socket(AF_INET, SOCK_RAW, IPPROTO_RAW)) == -1) {
        perror("socket");
        exit(EXIT_FAILURE);
    }

    // 设置目标地址
    memset(&dest_addr, 0, sizeof(dest_addr));
    dest_addr.sin_family = AF_INET;
    dest_addr.sin_port = htons(DEST_PORT);
    inet_pton(AF_INET, DEST_IP, &dest_addr.sin_addr);

    // 构造IP数据包
    memset(packet, 0, sizeof(packet));
    struct ip *ip_header = (struct ip *)packet;
    ip_header->ip_v = 4;
    ip_header->ip_hl = 5;
    ip_header->ip_tos = 0;
    ip_header->ip_len = htons(sizeof(struct ip) + 8);
    ip_header->ip_id = htons(12345);
    ip_header->ip_off = 0;
    ip_header->ip_ttl = 64;
    ip_header->ip_p = IPPROTO_TCP;
    ip_header->ip_sum = 0; // 需要计算校验和
    inet_pton(AF_INET, DEST_IP, &ip_header->ip_dst);
    inet_pton(AF_INET, "192.168.1.2", &ip_header->ip_src);

    // 发送数据包
    if (sendto(sockfd, packet, sizeof(packet), 0, (struct sockaddr *)&dest_addr, sizeof(dest_addr)) == -1) {
        perror("sendto");
        close(sockfd);
        exit(EXIT_FAILURE);
    }

    printf("Packet sent successfully!\n");

    close(sockfd);
    return 0;
}

sudo setcap 'cap_net_raw=eip' /path/to/your/program