path: root/src/plugin_nfacct.c

#include "common.h"

#ifdef INTERNAL_PLUGIN_NFACCT

#ifdef HAVE_LIBMNL
#include <libmnl/libmnl.h>

static inline size_t mnl_buffer_size() {
    long s = MNL_SOCKET_BUFFER_SIZE;
    if(s <= 0) return 8192;
    return (size_t)s;
}

// ----------------------------------------------------------------------------
// DO_NFSTAT - collect netfilter connection tracker statistics via netlink
// example: https://github.com/formorer/pkg-conntrack-tools/blob/master/src/conntrack.c

#ifdef HAVE_LINUX_NETFILTER_NFNETLINK_CONNTRACK_H
#define DO_NFSTAT 1

#define RRD_TYPE_NET_STAT_NETFILTER "netfilter"
#define RRD_TYPE_NET_STAT_CONNTRACK "netlink" // FIXME: should be "conntrack" when merged with the /proc plugin

#include <linux/netfilter/nfnetlink_conntrack.h>

static struct {
    int update_every;
    char *buf;
    size_t buf_size;
    struct mnl_socket *mnl;
    struct nlmsghdr *nlh;
    struct nfgenmsg *nfh;
    unsigned int seq;
    uint32_t portid;

    struct nlattr *tb[CTA_STATS_MAX+1];
    const char *attr2name[CTA_STATS_MAX+1];
    kernel_uint_t metrics[CTA_STATS_MAX+1];

    struct nlattr *tb_exp[CTA_STATS_EXP_MAX+1];
    const char *attr2name_exp[CTA_STATS_EXP_MAX+1];
    kernel_uint_t metrics_exp[CTA_STATS_EXP_MAX+1];
} nfstat_root = {
        .update_every = 1,
        .buf = NULL,
        .buf_size = 0,
        .mnl = NULL,
        .nlh = NULL,
        .nfh = NULL,
        .seq = 0,
        .portid = 0,
        .tb = {},
        .attr2name = {
                [CTA_STATS_SEARCHED]	   = "searched",
                [CTA_STATS_FOUND]	       = "found",
                [CTA_STATS_NEW]		       = "new",
                [CTA_STATS_INVALID]	       = "invalid",
                [CTA_STATS_IGNORE]	       = "ignore",
                [CTA_STATS_DELETE]	       = "delete",
                [CTA_STATS_DELETE_LIST]	   = "delete_list",
                [CTA_STATS_INSERT]	       = "insert",
                [CTA_STATS_INSERT_FAILED]  = "insert_failed",
                [CTA_STATS_DROP]	       = "drop",
                [CTA_STATS_EARLY_DROP]	   = "early_drop",
                [CTA_STATS_ERROR]	       = "icmp_error",
                [CTA_STATS_SEARCH_RESTART] = "search_restart",
        },
        .metrics = {},
        .tb_exp = {},
        .attr2name_exp = {
                [CTA_STATS_EXP_NEW]	       = "new",
                [CTA_STATS_EXP_CREATE]	   = "created",
                [CTA_STATS_EXP_DELETE]	   = "deleted",
        },
        .metrics_exp = {}
};


static int nfstat_init(int update_every) {
    nfstat_root.update_every = update_every;

    nfstat_root.buf_size = mnl_buffer_size();
    nfstat_root.buf = mallocz(nfstat_root.buf_size);

    nfstat_root.mnl  = mnl_socket_open(NETLINK_NETFILTER);
    if(!nfstat_root.mnl) {
        error("NFSTAT: mnl_socket_open() failed");
        return 1;
    }

    nfstat_root.seq = (unsigned int)now_realtime_sec() - 1;

    if(mnl_socket_bind(nfstat_root.mnl, 0, MNL_SOCKET_AUTOPID) < 0) {
        error("NFSTAT: mnl_socket_bind() failed");
        return 1;
    }
    nfstat_root.portid = mnl_socket_get_portid(nfstat_root.mnl);

    return 0;
}

static void nfstat_cleanup() {
    if(nfstat_root.mnl) {
        mnl_socket_close(nfstat_root.mnl);
        nfstat_root.mnl = NULL;
    }

    freez(nfstat_root.buf);
    nfstat_root.buf = NULL;
    nfstat_root.buf_size = 0;
}

static struct nlmsghdr * nfct_mnl_nlmsghdr_put(char *buf, uint16_t subsys, uint16_t type, uint8_t family, uint32_t seq) {
    struct nlmsghdr *nlh;
    struct nfgenmsg *nfh;

    nlh = mnl_nlmsg_put_header(buf);
    nlh->nlmsg_type = (subsys << 8) | type;
    nlh->nlmsg_flags = NLM_F_REQUEST|NLM_F_DUMP;
    nlh->nlmsg_seq = seq;

    nfh = mnl_nlmsg_put_extra_header(nlh, sizeof(struct nfgenmsg));
    nfh->nfgen_family = family;
    nfh->version = NFNETLINK_V0;
    nfh->res_id = 0;

    return nlh;
}

static int nfct_stats_attr_cb(const struct nlattr *attr, void *data) {
    const struct nlattr **tb = data;
    int type = mnl_attr_get_type(attr);

    if (mnl_attr_type_valid(attr, CTA_STATS_MAX) < 0)
        return MNL_CB_OK;

    if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0) {
        error("NFSTAT: mnl_attr_validate() failed");
        return MNL_CB_ERROR;
    }

    tb[type] = attr;
    return MNL_CB_OK;
}

static int nfstat_callback(const struct nlmsghdr *nlh, void *data) {
    (void)data;

    struct nfgenmsg *nfg = mnl_nlmsg_get_payload(nlh);

    mnl_attr_parse(nlh, sizeof(*nfg), nfct_stats_attr_cb, nfstat_root.tb);

    // printf("cpu=%-4u\t", ntohs(nfg->res_id));

    int i;
    // add the metrics of this CPU into the metrics
    for (i = 0; i < CTA_STATS_MAX+1; i++) {
        if (nfstat_root.tb[i]) {
            // printf("%s=%u ", nfstat_root.attr2name[i], ntohl(mnl_attr_get_u32(nfstat_root.tb[i])));
            nfstat_root.metrics[i] += ntohl(mnl_attr_get_u32(nfstat_root.tb[i]));
        }
    }
    // printf("\n");

    return MNL_CB_OK;
}

static int nfstat_collect_conntrack() {
    // zero all metrics - we will sum the metrics of all CPUs later
    int i;
    for (i = 0; i < CTA_STATS_MAX+1; i++)
        nfstat_root.metrics[i] = 0;

    // prepare the request
    nfstat_root.nlh = nfct_mnl_nlmsghdr_put(nfstat_root.buf, NFNL_SUBSYS_CTNETLINK, IPCTNL_MSG_CT_GET_STATS_CPU, AF_UNSPEC, nfstat_root.seq);

    // send the request
    if(mnl_socket_sendto(nfstat_root.mnl, nfstat_root.nlh, nfstat_root.nlh->nlmsg_len) < 0) {
        error("NFSTAT: mnl_socket_sendto() failed");
        return 1;
    }

    // get the reply
    ssize_t ret;
    while ((ret = mnl_socket_recvfrom(nfstat_root.mnl, nfstat_root.buf, nfstat_root.buf_size)) > 0) {
        if(mnl_cb_run(
                nfstat_root.buf
                , (size_t)ret
                , nfstat_root.nlh->nlmsg_seq
                , nfstat_root.portid
                , nfstat_callback
                , NULL
        ) <= MNL_CB_STOP)
            break;
    }

    // verify we run without issues
    if (ret == -1) {
        error("NFSTAT: error communicating with kernel. This plugin can only work when netdata runs as root.");
        return 1;
    }

    return 0;
}

static int nfexp_stats_attr_cb(const struct nlattr *attr, void *data)
{
    const struct nlattr **tb = data;
    int type = mnl_attr_get_type(attr);

    if (mnl_attr_type_valid(attr, CTA_STATS_EXP_MAX) < 0)
        return MNL_CB_OK;

    if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0) {
        error("NFSTAT EXP: mnl_attr_validate() failed");
        return MNL_CB_ERROR;
    }

    tb[type] = attr;
    return MNL_CB_OK;
}

static int nfstat_callback_exp(const struct nlmsghdr *nlh, void *data) {
    (void)data;

    struct nfgenmsg *nfg = mnl_nlmsg_get_payload(nlh);

    mnl_attr_parse(nlh, sizeof(*nfg), nfexp_stats_attr_cb, nfstat_root.tb_exp);

    int i;
    for (i = 0; i < CTA_STATS_EXP_MAX+1; i++) {
        if (nfstat_root.tb_exp[i]) {
            nfstat_root.metrics_exp[i] += ntohl(mnl_attr_get_u32(nfstat_root.tb_exp[i]));
        }
    }

    return MNL_CB_OK;
}

static int nfstat_collect_conntrack_expectations() {
    // zero all metrics - we will sum the metrics of all CPUs later
    int i;
    for (i = 0; i < CTA_STATS_EXP_MAX+1; i++)
        nfstat_root.metrics_exp[i] = 0;

    // prepare the request
    nfstat_root.nlh = nfct_mnl_nlmsghdr_put(nfstat_root.buf, NFNL_SUBSYS_CTNETLINK_EXP, IPCTNL_MSG_EXP_GET_STATS_CPU, AF_UNSPEC, nfstat_root.seq);

    // send the request
    if(mnl_socket_sendto(nfstat_root.mnl, nfstat_root.nlh, nfstat_root.nlh->nlmsg_len) < 0) {
        error("NFSTAT: mnl_socket_sendto() failed");
        return 1;
    }

    // get the reply
    ssize_t ret;
    while ((ret = mnl_socket_recvfrom(nfstat_root.mnl, nfstat_root.buf, nfstat_root.buf_size)) > 0) {
        if(mnl_cb_run(
                nfstat_root.buf
                , (size_t)ret
                , nfstat_root.nlh->nlmsg_seq
                , nfstat_root.portid
                , nfstat_callback_exp
                , NULL
        ) <= MNL_CB_STOP)
            break;
    }

    // verify we run without issues
    if (ret == -1) {
        error("NFSTAT: error communicating with kernel. This plugin can only work when netdata runs as root.");
        return 1;
    }

    return 0;
}

static int nfstat_collect() {
    nfstat_root.seq++;

    if(nfstat_collect_conntrack())
        return 1;

    if(nfstat_collect_conntrack_expectations())
        return 1;

    return 0;
}

static void nfstat_send_metrics() {

    {
        static RRDSET *st_new = NULL;
        static RRDDIM *rd_new = NULL, *rd_ignore = NULL, *rd_invalid = NULL;

        if(!st_new) {
            st_new = rrdset_create_localhost(
                    RRD_TYPE_NET_STAT_NETFILTER
                    , RRD_TYPE_NET_STAT_CONNTRACK "_new"
                    , NULL
                    , RRD_TYPE_NET_STAT_CONNTRACK
                    , NULL
                    , "Connection Tracker New Connections"
                    , "connections/s"
                    , 3001
                    , nfstat_root.update_every
                    , RRDSET_TYPE_LINE
            );

            rd_new     = rrddim_add(st_new, nfstat_root.attr2name[CTA_STATS_NEW], NULL, 1, 1, RRD_ALGORITHM_INCREMENTAL);
            rd_ignore  = rrddim_add(st_new, nfstat_root.attr2name[CTA_STATS_IGNORE], NULL, -1, 1, RRD_ALGORITHM_INCREMENTAL);
            rd_invalid = rrddim_add(st_new, nfstat_root.attr2name[CTA_STATS_INVALID], NULL, -1, 1, RRD_ALGORITHM_INCREMENTAL);
        }
        else
            rrdset_next(st_new);

        rrddim_set_by_pointer(st_new, rd_new, (collected_number) nfstat_root.metrics[CTA_STATS_NEW]);
        rrddim_set_by_pointer(st_new, rd_ignore, (collected_number) nfstat_root.metrics[CTA_STATS_IGNORE]);
        rrddim_set_by_pointer(st_new, rd_invalid, (collected_number) nfstat_root.metrics[CTA_STATS_INVALID]);

        rrdset_done(st_new);
    }

    // ----------------------------------------------------------------

    {
        static RRDSET *st_changes = NULL;
        static RRDDIM *rd_inserted = NULL, *rd_deleted = NULL, *rd_delete_list = NULL;

        if(!st_changes) {
            st_changes = rrdset_create_localhost(
                    RRD_TYPE_NET_STAT_NETFILTER
                    , RRD_TYPE_NET_STAT_CONNTRACK "_changes"
                    , NULL
                    , RRD_TYPE_NET_STAT_CONNTRACK
                    , NULL
                    , "Connection Tracker Changes"
                    , "changes/s"
                    , 3002
                    , nfstat_root.update_every
                    , RRDSET_TYPE_LINE
            );
            rrdset_flag_set(st_changes, RRDSET_FLAG_DETAIL);

            rd_inserted = rrddim_add(st_changes, nfstat_root.attr2name[CTA_STATS_INSERT], NULL, 1, 1, RRD_ALGORITHM_INCREMENTAL);
            rd_deleted = rrddim_add(st_changes, nfstat_root.attr2name[CTA_STATS_DELETE], NULL, -1, 1, RRD_ALGORITHM_INCREMENTAL);
            rd_delete_list = rrddim_add(st_changes, nfstat_root.attr2name[CTA_STATS_DELETE_LIST], NULL, -1, 1, RRD_ALGORITHM_INCREMENTAL);
        }
        else
            rrdset_next(st_changes);

        rrddim_set_by_pointer(st_changes, rd_inserted, (collected_number) nfstat_root.metrics[CTA_STATS_INSERT]);
        rrddim_set_by_pointer(st_changes, rd_deleted, (collected_number) nfstat_root.metrics[CTA_STATS_DELETE]);
        rrddim_set_by_pointer(st_changes, rd_delete_list, (collected_number) nfstat_root.metrics[CTA_STATS_DELETE_LIST]);

        rrdset_done(st_changes);
    }

    // ----------------------------------------------------------------

    {
        static RRDSET *st_search = NULL;
        static RRDDIM *rd_searched = NULL, *rd_restarted = NULL, *rd_found = NULL;

        if(!st_search) {
            st_search = rrdset_create_localhost(
                    RRD_TYPE_NET_STAT_NETFILTER
                    , RRD_TYPE_NET_STAT_CONNTRACK "_search"
                    , NULL
                    , RRD_TYPE_NET_STAT_CONNTRACK
                    , NULL
                    , "Connection Tracker Searches"
                    , "searches/s"
                    , 3010
                    , nfstat_root.update_every
                    , RRDSET_TYPE_LINE
            );
            rrdset_flag_set(st_search, RRDSET_FLAG_DETAIL);

            rd_searched = rrddim_add(st_search, nfstat_root.attr2name[CTA_STATS_SEARCHED], NULL, 1, 1, RRD_ALGORITHM_INCREMENTAL);
            rd_restarted = rrddim_add(st_search, nfstat_root.attr2name[CTA_STATS_SEARCH_RESTART], NULL, -1, 1, RRD_ALGORITHM_INCREMENTAL);
            rd_found = rrddim_add(st_search, nfstat_root.attr2name[CTA_STATS_FOUND], NULL, 1, 1, RRD_ALGORITHM_INCREMENTAL);
        }
        else
            rrdset_next(st_search);

        rrddim_set_by_pointer(st_search, rd_searched, (collected_number) nfstat_root.metrics[CTA_STATS_SEARCHED]);
        rrddim_set_by_pointer(st_search, rd_restarted, (collected_number) nfstat_root.metrics[CTA_STATS_SEARCH_RESTART]);
        rrddim_set_by_pointer(st_search, rd_found, (collected_number) nfstat_root.metrics[CTA_STATS_FOUND]);

        rrdset_done(st_search);
    }

    // ----------------------------------------------------------------

    {
        static RRDSET *st_errors = NULL;
        static RRDDIM *rd_error = NULL, *rd_insert_failed = NULL, *rd_drop = NULL, *rd_early_drop = NULL;

        if(!st_errors) {
            st_errors = rrdset_create_localhost(
                    RRD_TYPE_NET_STAT_NETFILTER
                    , RRD_TYPE_NET_STAT_CONNTRACK "_errors"
                    , NULL
                    , RRD_TYPE_NET_STAT_CONNTRACK
                    , NULL
                    , "Connection Tracker Errors"
                    , "events/s"
                    , 3005
                    , nfstat_root.update_every
                    , RRDSET_TYPE_LINE
            );
            rrdset_flag_set(st_errors, RRDSET_FLAG_DETAIL);

            rd_error = rrddim_add(st_errors, nfstat_root.attr2name[CTA_STATS_ERROR], NULL, 1, 1, RRD_ALGORITHM_INCREMENTAL);
            rd_insert_failed = rrddim_add(st_errors, nfstat_root.attr2name[CTA_STATS_INSERT_FAILED], NULL, -1, 1, RRD_ALGORITHM_INCREMENTAL);
            rd_drop = rrddim_add(st_errors, nfstat_root.attr2name[CTA_STATS_DROP], NULL, -1, 1, RRD_ALGORITHM_INCREMENTAL);
            rd_early_drop = rrddim_add(st_errors, nfstat_root.attr2name[CTA_STATS_EARLY_DROP], NULL, -1, 1, RRD_ALGORITHM_INCREMENTAL);
        }
        else
            rrdset_next(st_errors);

        rrddim_set_by_pointer(st_errors, rd_error, (collected_number) nfstat_root.metrics[CTA_STATS_ERROR]);
        rrddim_set_by_pointer(st_errors, rd_insert_failed, (collected_number) nfstat_root.metrics[CTA_STATS_INSERT_FAILED]);
        rrddim_set_by_pointer(st_errors, rd_drop, (collected_number) nfstat_root.metrics[CTA_STATS_DROP]);
        rrddim_set_by_pointer(st_errors, rd_early_drop, (collected_number) nfstat_root.metrics[CTA_STATS_EARLY_DROP]);

        rrdset_done(st_errors);
    }

    // ----------------------------------------------------------------

    {
        static RRDSET *st_expect = NULL;
        static RRDDIM *rd_new = NULL, *rd_created = NULL, *rd_deleted = NULL;

        if(!st_expect) {
            st_expect = rrdset_create_localhost(
                    RRD_TYPE_NET_STAT_NETFILTER
                    , RRD_TYPE_NET_STAT_CONNTRACK "_expect"
                    , NULL
                    , RRD_TYPE_NET_STAT_CONNTRACK
                    , NULL
                    , "Connection Tracker Expectations"
                    , "expectations/s"
                    , 3003
                    , nfstat_root.update_every
                    , RRDSET_TYPE_LINE
            );
            rrdset_flag_set(st_expect, RRDSET_FLAG_DETAIL);

            rd_created = rrddim_add(st_expect, nfstat_root.attr2name_exp[CTA_STATS_EXP_CREATE], NULL, 1, 1, RRD_ALGORITHM_INCREMENTAL);
            rd_deleted = rrddim_add(st_expect, nfstat_root.attr2name_exp[CTA_STATS_EXP_DELETE], NULL, -1, 1, RRD_ALGORITHM_INCREMENTAL);
            rd_new = rrddim_add(st_expect, nfstat_root.attr2name_exp[CTA_STATS_EXP_NEW], NULL, 1, 1, RRD_ALGORITHM_INCREMENTAL);
        }
        else
            rrdset_next(st_expect);

        rrddim_set_by_pointer(st_expect, rd_created, (collected_number) nfstat_root.metrics_exp[CTA_STATS_EXP_CREATE]);
        rrddim_set_by_pointer(st_expect, rd_deleted, (collected_number) nfstat_root.metrics_exp[CTA_STATS_EXP_DELETE]);
        rrddim_set_by_pointer(st_expect, rd_new, (collected_number) nfstat_root.metrics_exp[CTA_STATS_EXP_NEW]);

        rrdset_done(st_expect);
    }

}

#endif // HAVE_LINUX_NETFILTER_NFNETLINK_CONNTRACK_H


// ----------------------------------------------------------------------------
// DO_NFACCT - collect netfilter accounting statistics via netlink

#ifdef HAVE_LIBNETFILTER_ACCT
#define DO_NFACCT 1

#include <libnetfilter_acct/libnetfilter_acct.h>

struct nfacct_data {
    char *name;
    uint32_t hash;

    uint64_t pkts;
    uint64_t bytes;

    RRDDIM *rd_bytes;
    RRDDIM *rd_packets;

    int updated;

    struct nfacct_data *next;
};

static struct {
    int update_every;
    char *buf;
    size_t buf_size;
    struct mnl_socket *mnl;
    struct nlmsghdr *nlh;
    unsigned int seq;
    uint32_t portid;
    struct nfacct *nfacct_buffer;
    struct nfacct_data *nfacct_metrics;
} nfacct_root = {
        .update_every = 1,
        .buf = NULL,
        .buf_size = 0,
        .mnl = NULL,
        .nlh = NULL,
        .seq = 0,
        .portid = 0,
        .nfacct_buffer = NULL,
        .nfacct_metrics = NULL
};

static inline struct nfacct_data *nfacct_data_get(const char *name, uint32_t hash) {
    struct nfacct_data *d = NULL, *last = NULL;
    for(d = nfacct_root.nfacct_metrics; d ; last = d, d = d->next) {
        if(unlikely(d->hash == hash && !strcmp(d->name, name)))
            return d;
    }

    d = callocz(1, sizeof(struct nfacct_data));
    d->name = strdupz(name);
    d->hash = hash;

    if(!last) {
        d->next = nfacct_root.nfacct_metrics;
        nfacct_root.nfacct_metrics = d;
    }
    else {
        d->next = last->next;
        last->next = d;
    }

    return d;
}

static int nfacct_init(int update_every) {
    nfacct_root.update_every = update_every;

    nfacct_root.buf_size = mnl_buffer_size();
    nfacct_root.buf = mallocz(nfacct_root.buf_size);

    nfacct_root.nfacct_buffer = nfacct_alloc();
    if(!nfacct_root.nfacct_buffer) {
        error("nfacct.plugin: nfacct_alloc() failed.");
        return 0;
    }

    nfacct_root.seq = (unsigned int)now_realtime_sec() - 1;

    nfacct_root.mnl  = mnl_socket_open(NETLINK_NETFILTER);
    if(!nfacct_root.mnl) {
        error("nfacct.plugin: mnl_socket_open() failed");
        return 1;
    }

    if(mnl_socket_bind(nfacct_root.mnl, 0, MNL_SOCKET_AUTOPID) < 0) {
        error("nfacct.plugin: mnl_socket_bind() failed");
        return 1;
    }
    nfacct_root.portid = mnl_socket_get_portid(nfacct_root.mnl);

    return 0;
}

static void nfacct_cleanup() {
    if(nfacct_root.mnl) {
        mnl_socket_close(nfacct_root.mnl);
        nfacct_root.mnl = NULL;
    }

    if(nfacct_root.nfacct_buffer) {
        nfacct_free(nfacct_root.nfacct_buffer);
        nfacct_root.nfacct_buffer = NULL;
    }

    freez(nfacct_root.buf);
    nfacct_root.buf = NULL;
    nfacct_root.buf_size = 0;

    // FIXME: cleanup the metrics linked list
}

static int nfacct_callback(const struct nlmsghdr *nlh, void *data) {
    (void)data;

    if(nfacct_nlmsg_parse_payload(nlh, nfacct_root.nfacct_buffer) < 0) {
        error("NFACCT: nfacct_nlmsg_parse_payload() failed.");
        return MNL_CB_OK;
    }

    const char *name = nfacct_attr_get_str(nfacct_root.nfacct_buffer, NFACCT_ATTR_NAME);
    uint32_t hash = simple_hash(name);

    struct nfacct_data *d = nfacct_data_get(name, hash);

    d->pkts  = nfacct_attr_get_u64(nfacct_root.nfacct_buffer, NFACCT_ATTR_PKTS);
    d->bytes = nfacct_attr_get_u64(nfacct_root.nfacct_buffer, NFACCT_ATTR_BYTES);
    d->updated = 1;

    return MNL_CB_OK;
}

static int nfacct_collect() {
    // mark all old metrics as not-updated
    struct nfacct_data *d;
    for(d = nfacct_root.nfacct_metrics; d ; d = d->next)
        d->updated = 0;

    // prepare the request
    nfacct_root.seq++;
    nfacct_root.nlh = nfacct_nlmsg_build_hdr(nfacct_root.buf, NFNL_MSG_ACCT_GET, NLM_F_DUMP, (uint32_t)nfacct_root.seq);
    if(!nfacct_root.nlh) {
        error("NFACCT: nfacct_nlmsg_build_hdr() failed");
        return 1;
    }

    // send the request
    if(mnl_socket_sendto(nfacct_root.mnl, nfacct_root.nlh, nfacct_root.nlh->nlmsg_len) < 0) {
        error("NFACCT: mnl_socket_sendto() failed");
        return 1;
    }

    // get the reply
    ssize_t ret;
    while((ret = mnl_socket_recvfrom(nfacct_root.mnl, nfacct_root.buf, nfacct_root.buf_size)) > 0) {
        if(mnl_cb_run(
                nfacct_root.buf
                , (size_t)ret
                , nfacct_root.seq
                , nfacct_root.portid
                , nfacct_callback
                , NULL
        ) <= 0)
            break;
    }

    // verify we run without issues
    if (ret == -1) {
        error("NFACCT: error communicating with kernel. This plugin can only work when netdata runs as root.");
        return 1;
    }

    return 0;
}

static void nfacct_send_metrics() {
    static RRDSET *st_bytes = NULL, *st_packets = NULL;

    if(!nfacct_root.nfacct_metrics) return;
    struct nfacct_data *d;

    if(!st_packets) {
        st_packets = rrdset_create_localhost(
                "netfilter"
                , "nfacct_packets"
                , NULL
                , "nfacct"
                , NULL
                , "Netfilter Accounting Packets"
                , "packets/s"
                , 3206
                , nfacct_root.update_every
                , RRDSET_TYPE_STACKED
        );
    }
    else rrdset_next(st_packets);

    for(d = nfacct_root.nfacct_metrics; d ; d = d->next) {
        if(likely(d->updated)) {
            if(unlikely(!d->rd_packets))
                d->rd_packets = rrddim_add(
                        st_packets
                        , d->name
                        , NULL
                        , 1
                        , nfacct_root.update_every
                        , RRD_ALGORITHM_INCREMENTAL
                );

            rrddim_set_by_pointer(
                    st_packets
                    , d->rd_packets
                    , (collected_number)d->pkts
            );
        }
    }

    rrdset_done(st_packets);

    // ----------------------------------------------------------------

    st_bytes = rrdset_find_bytype_localhost("netfilter", "nfacct_bytes");
    if(!st_bytes) {
        st_bytes = rrdset_create_localhost(
                "netfilter"
                , "nfacct_bytes"
                , NULL
                , "nfacct"
                , NULL
                , "Netfilter Accounting Bandwidth"
                , "kilobytes/s"
                , 3207
                , nfacct_root.update_every
                , RRDSET_TYPE_STACKED
        );
    }
    else rrdset_next(st_bytes);

    for(d = nfacct_root.nfacct_metrics; d ; d = d->next) {
        if(likely(d->updated)) {
            if(unlikely(!d->rd_bytes))
                d->rd_bytes = rrddim_add(
                        st_bytes
                        , d->name
                        , NULL
                        , 1
                        , 1000 * nfacct_root.update_every
                        , RRD_ALGORITHM_INCREMENTAL
                );

            rrddim_set_by_pointer(
                    st_bytes
                    , d->rd_bytes
                    , (collected_number)d->bytes
            );
        }
    }

    rrdset_done(st_bytes);
}

#endif // HAVE_LIBNETFILTER_ACCT
#endif // HAVE_LIBMNL

// ----------------------------------------------------------------------------

void *nfacct_main(void *ptr) {
    struct netdata_static_thread *static_thread = (struct netdata_static_thread *)ptr;

    info("NETFILTER thread created with task id %d", gettid());

    if(pthread_setcanceltype(PTHREAD_CANCEL_DEFERRED, NULL) != 0)
        error("NETFILTER: Cannot set pthread cancel type to DEFERRED.");

    if(pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL) != 0)
        error("NETFILTER: Cannot set pthread cancel state to ENABLE.");


    int update_every = (int)config_get_number("plugin:netfilter", "update every", localhost->rrd_update_every);
    if(update_every < localhost->rrd_update_every)
        update_every = localhost->rrd_update_every;

#ifdef DO_NFACCT
    int nfacct = !nfacct_init(update_every);
#endif

#ifdef DO_NFSTAT
    int nfstat = !nfstat_init(update_every);
#endif

    // ------------------------------------------------------------------------

    usec_t step = update_every * USEC_PER_SEC;
    heartbeat_t hb;
    heartbeat_init(&hb);
    for(;;) {
        heartbeat_dt_usec(&hb);
        heartbeat_next(&hb, step);

        if(unlikely(netdata_exit)) break;

#ifdef DO_NFACCT
        if(likely(nfacct)) {
            nfacct = !nfacct_collect();

            if(likely(nfacct))
                nfacct_send_metrics();
        }
#endif

#ifdef DO_NFSTAT
        if(likely(nfstat)) {
            nfstat = !nfstat_collect();

            if(likely(nfstat))
                nfstat_send_metrics();
        }
#endif
    }

    info("NETFILTER thread exiting");

#ifdef DO_NFACCT
    nfacct_cleanup();
#endif

#ifdef DO_NFSTAT
    nfstat_cleanup();
#endif

    static_thread->enabled = 0;
    pthread_exit(NULL);
    return NULL;
}

#endif // INTERNAL_PLUGIN_NFACCT