linux+raw使用教程

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

int main() {
    int sockfd;
    struct sockaddr_in dest_addr;
    char buffer[1024];

    // 创建RAW Socket
    if ((sockfd = socket(AF_INET, SOCK_RAW, IPPROTO_TCP)) == -1) {
        perror("socket");
        exit(EXIT_FAILURE);
    }

    memset(&dest_addr, 0, sizeof(dest_addr));
    dest_addr.sin_family = AF_INET;
    dest_addr.sin_port = htons(80);
    inet_pton(AF_INET, "192.168.1.1", &dest_addr.sin_addr);

    while (1) {
        ssize_t recv_len = recvfrom(sockfd, buffer, sizeof(buffer), 0, NULL, NULL);
        if (recv_len == -1) {
            perror("recvfrom");
            break;
        }
        printf("Received %zd bytes\n", recv_len);
    }

    close(sockfd);
    return 0;
}

sudo chmod +s /path/to/your/program

sudo ./your_program

sudo ifconfig eth0 mtu 1400