ctexp_events.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>

#include <libnetfilter_conntrack/libnetfilter_conntrack.h>

static int n = 0;

static int
ct_event_cb(enum nf_conntrack_msg_type type,struct nf_conntrack *ct, void *data)
{
        char buf[1024];

        nfct_snprintf(buf, sizeof(buf), ct, type, NFCT_O_PLAIN, NFCT_OF_TIME);
        printf("[CT] %s\n", buf);

        if (++n == 20)
                return NFCT_CB_STOP;

        return NFCT_CB_CONTINUE;
}

static int
exp_event_cb(enum nf_conntrack_msg_type type,struct nf_expect *exp, void *data)
{
        char buf[1024];

        nfexp_snprintf(buf, 1024, exp, type, NFCT_O_DEFAULT, 0);
        printf("[EXP] %s\n", buf);

        if (++n == 20)
                return NFCT_CB_STOP;

        return NFCT_CB_CONTINUE;
}

int main(void)
{
        int ret = 0;
        struct nfct_handle *h;

        h = nfct_open(NFNL_SUBSYS_NONE, NF_NETLINK_CONNTRACK_EXP_NEW |
                                        NF_NETLINK_CONNTRACK_EXP_UPDATE |
                                        NF_NETLINK_CONNTRACK_EXP_DESTROY |
                                        NF_NETLINK_CONNTRACK_NEW |
                                        NF_NETLINK_CONNTRACK_UPDATE |
                                        NF_NETLINK_CONNTRACK_DESTROY);
        if (h == NULL) {
                perror("nfct_open");
                return -1;
        }

        nfexp_callback_register(h, NFCT_T_ALL, exp_event_cb, NULL);
        nfct_callback_register(h, NFCT_T_ALL, ct_event_cb, NULL);

        printf("TEST: waiting for 20 expectation events...\n");

        /* we may use nfexp_catch() instead, it would also work. */
        ret = nfct_catch(h);

        printf("TEST: expectation events ");
        if (ret == -1)
                printf("(%d)(%s)\n", ret, strerror(errno));
        else
                printf("(OK)\n");

        nfct_close(h);

        ret == -1 ? exit(EXIT_FAILURE) : exit(EXIT_SUCCESS);
}