#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

#include <libnet.h>
#include <netinet/igmp.h>

/* Structure to represent IGMP extra information */
struct igmp_extra {
    u_int8_t igmp_version;
    char *igmp_tag;
    u_int8_t igmp_type;             /* IGMP type */
    u_int8_t igmp_code;             /* routing code */
    char *igmp_dst;
    int group_override_dst;
} g_igmp_pkts[] = {
    /* name,  type (or version+type), code */
    { 1, "query",  0x11, 0, "224.0.0.1", 0 },
    { 1, "report", 0x12, 0, "224.0.0.1", 1 },
    { 1, "dvmrp",  0x13, 0, "224.0.0.1", 0 },
    { 2, "query",  0x11, 1, "224.0.0.1", 0 },
    { 2, "report", 0x16, 1, "224.0.0.2", 1 },
    { 2, "leave",  0x17, 1, "224.0.0.2", 0 },
    { 0, 0, 0, 0 },
};

void usage(char *name)
{
    fprintf(stderr, "usage: %s -i ethdevice\n", name);
}

int main(int argc, char **argv)
{
    /* ip addresses */
    u_int32_t ip_src = 0;
    char *ip_src_str = NULL;

    /* libnet stuff */
    char neterr[LIBNET_ERRBUF_SIZE];
    libnet_t *netcontext = NULL;

    /* misc */
    int c;                      
    char *device = NULL;
    printf("IGMP packet generator\n\n");

    printf("Parsing command line...\n");
    while((c = getopt(argc, argv, "i:")) != EOF)
    {
        switch (c)
        {
            case 'i':
                printf("  Net interface = [%s]\n", optarg);
                device = optarg;
                break;

            default:
                usage(argv[0]);
                exit(1);
        }
    }
    if (!device)
    {
        usage(argv[0]);
        exit(EXIT_FAILURE);
    }

    printf("done\n");

    /*
     * Memory initialization
     */
    printf("Initializing libnet context...");
    netcontext = libnet_init(LIBNET_RAW4, device, neterr);
    if (!netcontext){
        fprintf(stderr,neterr);
        exit(1);
    }
    libnet_clear_packet(netcontext);
    if (!ip_src_str)
    {
        ip_src = libnet_get_ipaddr4(netcontext);
        ip_src_str = libnet_addr2name4(ip_src, LIBNET_DONT_RESOLVE);
    }

    printf("done\n");

    return 0;
}