gistfile1.txt

int main(int argc,char **argv)
{ 
        pcap_t *handle;
    char errbuf[PCAP_ERRBUF_SIZE];
        struct bpf_program fp;
    const char *pcap_file = "trafego1.pcap";
        bpf_u_int32 net;

        char *string_mac = "00:0f:20:2f:63:d9";
        char *string_ip = "189.126.11.82";

        char filter_exp[100];
           
        sprintf(filter_exp, "ether host %s and host %s", string_mac, string_ip);

        handle = pcap_open_offline(pcap_file, errbuf);

        if (handle == NULL) {
                fprintf(stderr, "Couldn't open pcap file %s\n", errbuf);
                return 1;
        }

        if (pcap_compile(handle, &fp, filter_exp, 0, net) == -1) {
                fprintf(stderr, "Couldn't parse filter %s: %s\n", filter_exp, pcap_geterr(handle));
                return(2);
        }

        if (pcap_setfilter(handle, &fp) == -1) {
                fprintf(stderr, "Couldn't install filter %s: %s\n", filter_exp, pcap_geterr(handle));
                return(2);
        }

    // read and dispatch packets until EOF is reached
        pcap_loop(handle , -1 , my_callback, NULL);

        printf("TCP packets: %u\n", counter_tcp);
    return 0;
}