void process_promisc(void* buf, uint16_t len)
{   
    char* buflen = (char*) buf + len;
    uint8_t hexdump_cols = 0;
    uint8_t offset = 0;

    // RAW packet
    for (char* ptr = buf; ptr < buflen; ptr++) printf("%c", *ptr);
    printf("\n\n");

    // Hexdump (wireshark-friendly)
    for (char* ptr = buf; ptr < buflen; ptr++) {
        // print offset
        printf("%06X", offset);

        for (hexdump_cols=0; hexdump_cols < HEX_COLSIZE; hexdump_cols++) 
            printf("%02X ", *ptr + hexdump_cols);
        
        offset = offset + HEX_COLSIZE;
        printf("\n");
    }

    //free(buf);
    //free(buflen);

    printf("\n\n");
}