#include <arpa/inet.h>
#include <netinet/if_ether.h>
#include <netinet/ip.h>
#include <netinet/udp.h>
#include <pcap.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define SOURCE_PORT 14236
#define DEST_PORT 14235

char* ether_ntoa(const struct ether_addr* addr)
{
    static char buf[18];
    snprintf(buf, sizeof(buf), "%02x:%02x:%02x:%02x:%02x:%02x",
        addr->ether_addr_octet[0], addr->ether_addr_octet[1],
        addr->ether_addr_octet[2], addr->ether_addr_octet[3],
        addr->ether_addr_octet[4], addr->ether_addr_octet[5]);
    return buf;
}

void packet_handler(unsigned char* user, const struct pcap_pkthdr* h, const unsigned char* bytes)
{
    struct ether_header* eth_header;
    struct ip* ip_header;
    struct udphdr* udp_header;

    eth_header = (struct ether_header*)bytes;

    // Check if the packet is an IP packet
    if (ntohs(eth_header->ether_type) == ETHERTYPE_IP) {
        ip_header = (struct ip*)(bytes + sizeof(struct ether_header));

        // Check if the packet is a UDP packet
        if (ip_header->ip_p == IPPROTO_UDP) {
            udp_header = (struct udphdr*)(bytes + sizeof(struct ether_header) + sizeof(struct ip));

            // Convert IP addresses from network byte order to text
            char source_ip[INET_ADDRSTRLEN];
            char dest_ip[INET_ADDRSTRLEN];
            inet_ntop(AF_INET, &(ip_header->ip_src), source_ip, INET_ADDRSTRLEN);
            inet_ntop(AF_INET, &(ip_header->ip_dst), dest_ip, INET_ADDRSTRLEN);

            // Check if the destination IP address and UDP ports match
            if (strcmp(dest_ip, "255.255.255.255") == 0 && ntohs(udp_header->source) == SOURCE_PORT && ntohs(udp_header->dest) == DEST_PORT) {

                // Convert MAC address to readable format
                char source_mac[18];
                snprintf(source_mac, sizeof(source_mac), "%s", ether_ntoa((struct ether_addr*)eth_header->ether_shost));

                // Print the extracted information
                printf("Miner IP: %s\n", source_ip);
                printf("Source MAC Address: %s\n", source_mac);
                printf("----------------------------------------\n");
            }
        }
    }
}

char* get_default_interface()
{
    pcap_if_t *alldevs, *d;
    char errbuf[PCAP_ERRBUF_SIZE];
    char* dev = NULL;

    if (pcap_findalldevs(&alldevs, errbuf) == -1) {
        fprintf(stderr, "Error finding devices: %s\n", errbuf);
        return NULL;
    }

    // Find the first interface that is up
    for (d = alldevs; d != NULL; d = d->next) {
        if (d->flags & PCAP_IF_UP) {
            dev = strdup(d->name); // Duplicate the interface name
            break;
        }
    }

    pcap_freealldevs(alldevs); // Free the device list

    if (dev == NULL) {
        fprintf(stderr, "No suitable device found\n");
        return NULL;
    }

    return dev;
}

int main()
{
    char errbuf[PCAP_ERRBUF_SIZE];
    pcap_t* handle;
    char* dev = get_default_interface();

    if (dev == NULL) {
        return 2; // No suitable device found
    }

    printf("Using device: %s\n", dev);

    // Open the device for capturing
    handle = pcap_open_live(dev, BUFSIZ, 1, 1000, errbuf);
    free(dev); // Free the duplicated device name string

    if (handle == NULL) {
        fprintf(stderr, "Could not open device: %s\n", errbuf);
        return 2;
    }

    printf("Listening...\n");

    // Start the packet capture loop
    pcap_loop(handle, 0, packet_handler, NULL);

    // Close the capture handle
    pcap_close(handle);

    return 0;
}