nfacct-get.c

/* This example is in the public domain. */
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <libmnl/libmnl.h>
#include <libnetfilter_acct/libnetfilter_acct.h>

static int nfacct_cb(const struct nlmsghdr *nlh, void *data)
{
        struct nfacct *nfacct;
        char buf[4096];

        nfacct = nfacct_alloc();
        if (nfacct == NULL) {
                perror("OOM");
                goto err;
        }

        if (nfacct_nlmsg_parse_payload(nlh, nfacct) < 0) {
                perror("nfacct_parse_nl_msg");
                goto err_free;
        }

        nfacct_snprintf(buf, sizeof(buf), nfacct,
                        NFACCT_SNPRINTF_T_PLAIN, NFACCT_SNPRINTF_F_FULL);
        printf("%s\n", buf);

err_free:
        nfacct_free(nfacct);
err:
        return MNL_CB_OK;
}

int main(int argc, char *argv[])
{
        struct mnl_socket *nl;
        char buf[MNL_SOCKET_BUFFER_SIZE];
        struct nlmsghdr *nlh;
        uint32_t portid, seq;
        int ret, full = 1;
        bool zeroctr = false;

        if (argc > 2) {
                fprintf(stderr, "Usage: %s [-z]\n", argv[0]);
                exit(EXIT_FAILURE);
        }

        if (argc == 2 && strncmp(argv[1], "-z", strlen("-z")) == 0)
                zeroctr = true;

        seq = time(NULL);
        nlh = nfacct_nlmsg_build_hdr(buf, zeroctr ?
                                        NFNL_MSG_ACCT_GET_CTRZERO :
                                        NFNL_MSG_ACCT_GET,
                                     NLM_F_DUMP, seq);

        nl = mnl_socket_open(NETLINK_NETFILTER);
        if (nl == NULL) {
                perror("mnl_socket_open");
                exit(EXIT_FAILURE);
        }

        if (mnl_socket_bind(nl, 0, MNL_SOCKET_AUTOPID) < 0) {
                perror("mnl_socket_bind");
                exit(EXIT_FAILURE);
        }
        portid = mnl_socket_get_portid(nl);

        if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) {
                perror("mnl_socket_send");
                exit(EXIT_FAILURE);
        }

        ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
        while (ret > 0) {
                ret = mnl_cb_run(buf, ret, seq, portid, nfacct_cb, &full);
                if (ret <= 0)
                        break;
                ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
        }
        if (ret == -1) {
                perror("error");
                exit(EXIT_FAILURE);
        }
        mnl_socket_close(nl);

        return EXIT_SUCCESS;
}