#include <stdlib.h>
#include <stdio.h>
#include <fcntl.h>
#include <sys/uio.h>
#include <unistd.h>
#include <string.h>
#include <sys/errno.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#include <net/bpf.h>
#include <netinet/tcp.h>
#include <netinet/ip.h>
#include <netinet/if_ether.h>
#include <netinet/in.h>
#include <net/if.h>
#include <arpa/inet.h>

#include "bpf.h"

int main()
{
    BpfOption option;
    strcpy(option.interfaceName, "en0");
    option.bufferLength = 32767;
    print_bpf_options(option);

    BpfSniffer sniffer;
    if (new_bpf_sniffer(option, &sniffer) == -1)
        return 1;

    print_bpf_sniffer_params(sniffer);

    CapturedInfo info;
    int dataLength;
    while((dataLength = read_bpf_packet_data(&sniffer, &info)) != -1) {
        printf("--------------------------------------------------\n");
        printf("Payload length: %d\n", dataLength);
        struct ether_header* eh = (struct ether_header*)info.data;
        printf(" Ethernet Frame\n");
        printf("  src mac address: %x:%x:%x:%x:%x:%x\n",
               eh->ether_shost[0],
               eh->ether_shost[1],
               eh->ether_shost[2],
               eh->ether_shost[3],
               eh->ether_shost[4],
               eh->ether_shost[5]);

        printf("  dst mac address: %x:%x:%x:%x:%x:%x\n",
               eh->ether_dhost[0],
               eh->ether_dhost[1],
               eh->ether_dhost[2],
               eh->ether_dhost[3],
               eh->ether_dhost[4],
               eh->ether_dhost[5]);

        if (ntohs(eh->ether_type) == ETHERTYPE_IP) {
            printf("  type: IPv4, %x\n", eh->ether_type);

            struct ip* ip = (struct ip*)((long)eh + sizeof(struct ether_header));
            printf(" IP Frame\n");
            printf("  headerLength: %d\n", ip->ip_hl * 4);
            printf("  version: %d\n", ip->ip_v);
            printf("  protocol: %d\n", ip->ip_p);
            printf("  ttl: %d\n", ip->ip_ttl);
            printf("  dst ip: %s\n", inet_ntoa(ip->ip_dst));
            printf("  src ip: %s\n", inet_ntoa(ip->ip_src));

            if (ip->ip_p == IPPROTO_TCP) {
                struct tcphdr* tcp = (struct tcphdr*)((long)ip + (ip->ip_hl * 4));
                printf(" TCP Packet\n");
                printf("  dst port: %d\n", tcp->th_dport);
                printf("  src port: %d\n", tcp->th_sport);
            }
        } else {
            printf("  type: Other, %x\n", eh->ether_type);
        }
    }
    close_bpf_sniffer(&sniffer);
    return 0;
}