#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <pfring.h>
#include <arpa/inet.h>
#include <netinet/ip.h>
#include <netinet/tcp.h>
// #include <unistd.h> 

void packet_handler(const struct pfring_pkthdr *header, const u_char *packet) {
    struct ip *ip_header = (struct ip *)(packet + 14); // 以太网帧
    printf("捕获到数据包: 长度 %u 字节\n", header->len);

    // 检查是否为 IPv4 数据包
    if (ip_header->ip_v == 4) {
        // 测试：只处理 TCP 包
        if (ip_header->ip_p == IPPROTO_TCP) {
            char src_ip[INET_ADDRSTRLEN];
            char dst_ip[INET_ADDRSTRLEN];

            inet_ntop(AF_INET, &(ip_header->ip_src), src_ip, INET_ADDRSTRLEN);
            inet_ntop(AF_INET, &(ip_header->ip_dst), dst_ip, INET_ADDRSTRLEN);

            printf("源 IP 地址: %s\n", src_ip);
            printf("目标 IP 地址: %s\n", dst_ip);

            struct tcphdr *tcp_header = (struct tcphdr *)(packet + 14 + (ip_header->ip_hl * 4));
            printf("协议: TCP\n");
            printf("源端口: %u\n", ntohs(tcp_header->source));
            printf("目标端口: %u\n", ntohs(tcp_header->dest));
            printf("----------\n");
        }
    } else {
        printf("不是 IPv4 数据包\n");
    }
}

// 简单测试pf_ring抓包
int main(int argc, char *argv[]) {
    if (argc != 3 || strcmp(argv[1], "-i") != 0) {
        fprintf(stderr, "用法: %s -i <网口名称>\n", argv[0]);
        return -1;
    }

    char *device = argv[2]; // 获取网口名称
    int snaplen = 1500;
    int promiscuous = 1;
    int rc;

    pfring *ring = pfring_open(device, snaplen, promiscuous);
    if (ring == NULL) {
        fprintf(stderr, "打开设备 %s 时出错\n", device);
        return -1;
    }

    pfring_set_application_name(ring, "SimplePF_RINGPacketSniffer");
    pfring_set_direction(ring, rx_and_tx_direction); // 设置抓取接收和发送的数据包

    rc = pfring_enable_ring(ring);
    if (rc != 0) {
        fprintf(stderr, "启用 ring 时出错\n");
        pfring_close(ring);
        return -1;
    }

    struct pfring_pkthdr header;
    u_char *packet;

    while (1) {
        if (pfring_recv(ring, &packet, 0, &header, 1) > 0) {
            packet_handler(&header, packet);
        }
    }

    pfring_close(ring);
    return 0;
}