netem.c

/* SPDX-License-Identifier: LGPL-2.1-only */
/*
 * Copyright (c) 2003-2011 Thomas Graf <tgraf@suug.ch>
 */
 
/**
 * @ingroup qdisc
 * @defgroup qdisc_netem Network Emulator
 * @brief
 *
 * For further documentation see http://linux-net.osdl.org/index.php/Netem
 * @{
 */
 
#include <netlink-private/netlink.h>
#include <netlink-private/tc.h>
#include <netlink/netlink.h>
#include <netlink/utils.h>
#include <netlink-private/route/tc-api.h>
#include <netlink/route/qdisc.h>
#include <netlink/route/qdisc/netem.h>
 
#include "netlink-private/utils.h"
 
/** @cond SKIP */
#define SCH_NETEM_ATTR_LATENCY          0x0001
#define SCH_NETEM_ATTR_LIMIT            0x0002
#define SCH_NETEM_ATTR_LOSS             0x0004
#define SCH_NETEM_ATTR_GAP              0x0008
#define SCH_NETEM_ATTR_DUPLICATE        0x0010
#define SCH_NETEM_ATTR_JITTER           0x0020
#define SCH_NETEM_ATTR_DELAY_CORR       0x0040
#define SCH_NETEM_ATTR_LOSS_CORR        0x0080
#define SCH_NETEM_ATTR_DUP_CORR         0x0100
#define SCH_NETEM_ATTR_RO_PROB          0x0200
#define SCH_NETEM_ATTR_RO_CORR          0x0400
#define SCH_NETEM_ATTR_CORRUPT_PROB     0x0800
#define SCH_NETEM_ATTR_CORRUPT_CORR     0x1000
#define SCH_NETEM_ATTR_DIST             0x2000
/** @endcond */
 
static struct nla_policy netem_policy[TCA_NETEM_MAX+1] = {
        [TCA_NETEM_CORR]        = { .minlen = sizeof(struct tc_netem_corr) },
        [TCA_NETEM_REORDER]     = { .minlen = sizeof(struct tc_netem_reorder) },
        [TCA_NETEM_CORRUPT]     = { .minlen = sizeof(struct tc_netem_corrupt) },
};
 
static int netem_msg_parser(struct rtnl_tc *tc, void *data)
{
        struct rtnl_netem *netem = data;
        struct tc_netem_qopt *opts;
        int len, err = 0;
 
        if (tc->tc_opts->d_size < sizeof(*opts))
                return -NLE_INVAL;
 
        opts = (struct tc_netem_qopt *) tc->tc_opts->d_data;
        netem->qnm_latency = opts->latency;
        netem->qnm_limit = opts->limit;
        netem->qnm_loss = opts->loss;
        netem->qnm_gap = opts->gap;
        netem->qnm_duplicate = opts->duplicate;
        netem->qnm_jitter = opts->jitter;
 
        netem->qnm_mask = (SCH_NETEM_ATTR_LATENCY | SCH_NETEM_ATTR_LIMIT |
                           SCH_NETEM_ATTR_LOSS | SCH_NETEM_ATTR_GAP |
                           SCH_NETEM_ATTR_DUPLICATE | SCH_NETEM_ATTR_JITTER);
 
        len = tc->tc_opts->d_size - sizeof(*opts);
 
        if (len > 0) {
                struct nlattr *tb[TCA_NETEM_MAX+1];
 
                err = nla_parse(tb, TCA_NETEM_MAX, (struct nlattr *)
                                ((char *) tc->tc_opts->d_data + sizeof(*opts)),
                                len, netem_policy);
                if (err < 0) {
                        free(netem);
                        return err;
                }
 
                if (tb[TCA_NETEM_CORR]) {
                        struct tc_netem_corr cor;
 
                        nla_memcpy(&cor, tb[TCA_NETEM_CORR], sizeof(cor));
                        netem->qnm_corr.nmc_delay = cor.delay_corr;
                        netem->qnm_corr.nmc_loss = cor.loss_corr;
                        netem->qnm_corr.nmc_duplicate = cor.dup_corr;
 
                        netem->qnm_mask |= (SCH_NETEM_ATTR_DELAY_CORR |
                                            SCH_NETEM_ATTR_LOSS_CORR |
                                        SCH_NETEM_ATTR_DUP_CORR);
                }
 
                if (tb[TCA_NETEM_REORDER]) {
                        struct tc_netem_reorder ro;
 
                        nla_memcpy(&ro, tb[TCA_NETEM_REORDER], sizeof(ro));
                        netem->qnm_ro.nmro_probability = ro.probability;
                        netem->qnm_ro.nmro_correlation = ro.correlation;
 
                        netem->qnm_mask |= (SCH_NETEM_ATTR_RO_PROB |
                                            SCH_NETEM_ATTR_RO_CORR);
                }
 
                if (tb[TCA_NETEM_CORRUPT]) {
                        struct tc_netem_corrupt corrupt;
 
                        nla_memcpy(&corrupt, tb[TCA_NETEM_CORRUPT], sizeof(corrupt));
                        netem->qnm_crpt.nmcr_probability = corrupt.probability;
                        netem->qnm_crpt.nmcr_correlation = corrupt.correlation;
 
                        netem->qnm_mask |= (SCH_NETEM_ATTR_CORRUPT_PROB |
                                                SCH_NETEM_ATTR_CORRUPT_CORR);
                }
 
                /* sch_netem does not currently dump TCA_NETEM_DELAY_DIST */
                netem->qnm_dist.dist_data = NULL;
                netem->qnm_dist.dist_size = 0;
        }
 
        return 0;
}
 
static void netem_free_data(struct rtnl_tc *tc, void *data)
{
        struct rtnl_netem *netem = data;
 
        if (!netem)
                return;
 
        free(netem->qnm_dist.dist_data);
}
 
static void netem_dump_line(struct rtnl_tc *tc, void *data,
                            struct nl_dump_params *p)
{
        struct rtnl_netem *netem = data;
 
        if (netem) {
                if (netem->qnm_mask & SCH_NETEM_ATTR_LIMIT && netem->qnm_limit > 0)
                        nl_dump(p, " limit %dpkts", netem->qnm_limit);
                else
                        nl_dump(p, " no limit");
        }
}
 
static void netem_dump_details(struct rtnl_tc *tc, void *data,
                               struct nl_dump_params *p)
{
        struct rtnl_netem *netem = data;
        char buf[32];
 
        if (netem) {
                if (netem->qnm_mask & SCH_NETEM_ATTR_LATENCY && netem->qnm_latency > 0) {
                        nl_msec2str(nl_ticks2us(netem->qnm_latency) / 1000, buf, sizeof(buf));
                        nl_dump(p, " latency %s", buf);
 
                        if (netem->qnm_mask & SCH_NETEM_ATTR_JITTER && netem->qnm_jitter > 0) {
                                nl_msec2str(nl_ticks2us(netem->qnm_jitter) / 1000, buf, sizeof(buf));
                                nl_dump(p, " jitter %s", buf);
 
                                if (netem->qnm_mask & SCH_NETEM_ATTR_DELAY_CORR && netem->qnm_corr.nmc_delay > 0)
                                        nl_dump(p, " %d", netem->qnm_corr.nmc_delay);
                        }
                }
 
                if (netem->qnm_mask & SCH_NETEM_ATTR_LOSS && netem->qnm_loss > 0) {
                        nl_dump(p, " loss %d", netem->qnm_loss);
 
                        if (netem->qnm_mask & SCH_NETEM_ATTR_LOSS_CORR && netem->qnm_corr.nmc_loss > 0)
                                nl_dump(p, " %d", netem->qnm_corr.nmc_loss);
                }
 
                if (netem->qnm_mask & SCH_NETEM_ATTR_DUPLICATE && netem->qnm_duplicate > 0) {
                        nl_dump(p, " duplicate %d", netem->qnm_duplicate);
 
                        if (netem->qnm_mask & SCH_NETEM_ATTR_DUP_CORR && netem->qnm_corr.nmc_duplicate > 0)
                                nl_dump(p, " %d", netem->qnm_corr.nmc_duplicate);
                }
 
                if (netem->qnm_mask & SCH_NETEM_ATTR_RO_PROB && netem->qnm_ro.nmro_probability > 0) {
                        nl_dump(p, " reorder %d", netem->qnm_ro.nmro_probability);
 
                        if (netem->qnm_mask & SCH_NETEM_ATTR_RO_CORR && netem->qnm_ro.nmro_correlation > 0)
                                nl_dump(p, " %d", netem->qnm_ro.nmro_correlation);
 
                        if (netem->qnm_mask & SCH_NETEM_ATTR_GAP && netem->qnm_gap > 0)
                                nl_dump(p, " gap %d", netem->qnm_gap);
                }
 
                if (netem->qnm_mask & SCH_NETEM_ATTR_CORRUPT_PROB && netem->qnm_crpt.nmcr_probability > 0) {
                        nl_dump(p, " reorder %d", netem->qnm_crpt.nmcr_probability);
 
                        if (netem->qnm_mask & SCH_NETEM_ATTR_CORRUPT_CORR && netem->qnm_crpt.nmcr_correlation > 0)
                                nl_dump(p, " %d", netem->qnm_crpt.nmcr_correlation);
                }
        }
}
 
static int netem_msg_fill_raw(struct rtnl_tc *tc, void *data,
                              struct nl_msg *msg)
{
        int err = 0;
        struct tc_netem_qopt opts;
        struct tc_netem_corr cor;
        struct tc_netem_reorder reorder;
        struct tc_netem_corrupt corrupt;
        struct rtnl_netem *netem = data;
 
        unsigned char set_correlation = 0, set_reorder = 0;
        unsigned char set_corrupt = 0, set_dist = 0;
 
        struct nlattr* head;
        struct nlattr* tail;
        int old_len;
 
        if (!netem)
                BUG();
 
        memset(&opts, 0, sizeof(opts));
        memset(&cor, 0, sizeof(cor));
        memset(&reorder, 0, sizeof(reorder));
        memset(&corrupt, 0, sizeof(corrupt));
 
        msg->nm_nlh->nlmsg_flags |= NLM_F_REQUEST;
 
        if (netem->qnm_ro.nmro_probability != 0) {
                if (netem->qnm_latency == 0)
                        return -NLE_MISSING_ATTR;
                if (netem->qnm_gap == 0)
                        netem->qnm_gap = 1;
        } else if (netem->qnm_gap)
                return -NLE_MISSING_ATTR;
 
        if (netem->qnm_corr.nmc_delay != 0) {
                if (netem->qnm_latency == 0 || netem->qnm_jitter == 0)
                        return -NLE_MISSING_ATTR;
                set_correlation = 1;
        }
 
        if (netem->qnm_corr.nmc_loss != 0) {
                if (netem->qnm_loss == 0)
                        return -NLE_MISSING_ATTR;
                set_correlation = 1;
        }
 
        if (netem->qnm_corr.nmc_duplicate != 0) {
                if (netem->qnm_duplicate == 0)
                        return -NLE_MISSING_ATTR;
                set_correlation = 1;
        }
 
        if (netem->qnm_ro.nmro_probability != 0)
                set_reorder = 1;
        else if (netem->qnm_ro.nmro_correlation != 0)
                return -NLE_MISSING_ATTR;
 
        if (netem->qnm_crpt.nmcr_probability != 0)
                set_corrupt = 1;
        else if (netem->qnm_crpt.nmcr_correlation != 0)
                return -NLE_MISSING_ATTR;
 
        if (netem->qnm_dist.dist_data && netem->qnm_dist.dist_size) {
                if (netem->qnm_latency == 0 || netem->qnm_jitter == 0)
                        return -NLE_MISSING_ATTR;
                else {
                        /* Resize to accomodate the large distribution table */
                        int new_msg_len = msg->nm_size + netem->qnm_dist.dist_size *
                                          sizeof(netem->qnm_dist.dist_data[0]);
                        struct nlmsghdr *new_nlh = realloc(msg->nm_nlh, new_msg_len);
 
                        if (new_nlh == NULL)
                                return -NLE_NOMEM;
                        msg->nm_nlh = new_nlh;
                        msg->nm_size = new_msg_len;
                        set_dist = 1;
                }
        }
 
        opts.latency = netem->qnm_latency;
        opts.limit = netem->qnm_limit ? netem->qnm_limit : 1000;
        opts.loss = netem->qnm_loss;
        opts.gap = netem->qnm_gap;
        opts.duplicate = netem->qnm_duplicate;
        opts.jitter = netem->qnm_jitter;
 
        NLA_PUT(msg, TCA_OPTIONS, sizeof(opts), &opts);
 
        if (set_correlation) {
                cor.delay_corr = netem->qnm_corr.nmc_delay;
                cor.loss_corr = netem->qnm_corr.nmc_loss;
                cor.dup_corr = netem->qnm_corr.nmc_duplicate;
 
                NLA_PUT(msg, TCA_NETEM_CORR, sizeof(cor), &cor);
        }
 
        if (set_reorder) {
                reorder.probability = netem->qnm_ro.nmro_probability;
                reorder.correlation = netem->qnm_ro.nmro_correlation;
 
                NLA_PUT(msg, TCA_NETEM_REORDER, sizeof(reorder), &reorder);
        }
 
        if (set_corrupt) {
                corrupt.probability = netem->qnm_crpt.nmcr_probability;
                corrupt.correlation = netem->qnm_crpt.nmcr_correlation;
 
                NLA_PUT(msg, TCA_NETEM_CORRUPT, sizeof(corrupt), &corrupt);
        }
 
        if (set_dist) {
                NLA_PUT(msg, TCA_NETEM_DELAY_DIST,
                        netem->qnm_dist.dist_size * sizeof(netem->qnm_dist.dist_data[0]),
                        netem->qnm_dist.dist_data);
        }
 
        /* Length specified in the TCA_OPTIONS section must span the entire
         * remainder of the message. That's just the way that sch_netem expects it.
         * Maybe there's a more succinct way to do this at a higher level.
         */
        head = (struct nlattr *)(((char *) NLMSG_DATA(msg->nm_nlh)) +
                                 NLMSG_LENGTH(sizeof(struct tcmsg)) - NLMSG_ALIGNTO);
 
        tail = (struct nlattr *)(((char *) (msg->nm_nlh)) +
                                 NLMSG_ALIGN(msg->nm_nlh->nlmsg_len));
 
        old_len = head->nla_len;
        head->nla_len = (char *)tail - (char *)head;
        msg->nm_nlh->nlmsg_len += (head->nla_len - old_len);
 
        return err;
nla_put_failure:
        return -NLE_MSGSIZE;
}
 
/**
 * @name Queue Limit
 * @{
 */
 
/**
 * Set limit of netem qdisc.
 * @arg qdisc           Netem qdisc to be modified.
 * @arg limit           New limit in bytes.
 * @return 0 on success or a negative error code.
 */
void rtnl_netem_set_limit(struct rtnl_qdisc *qdisc, int limit)
{
        struct rtnl_netem *netem;
 
        if (!(netem = rtnl_tc_data(TC_CAST(qdisc))))
                BUG();
 
        netem->qnm_limit = limit;
        netem->qnm_mask |= SCH_NETEM_ATTR_LIMIT;
}
 
/**
 * Get limit of netem qdisc.
 * @arg qdisc           Netem qdisc.
 * @return Limit in bytes or a negative error code.
 */
int rtnl_netem_get_limit(struct rtnl_qdisc *qdisc)
{
        struct rtnl_netem *netem;
 
        if (!(netem = rtnl_tc_data(TC_CAST(qdisc))))
                return -NLE_NOMEM;
 
        if (netem->qnm_mask & SCH_NETEM_ATTR_LIMIT)
                return netem->qnm_limit;
        else
                return -NLE_NOATTR;
}
 
/** @} */
 
/**
 * @name Packet Re-ordering
 * @{
 */
 
/**
 * Set re-ordering gap of netem qdisc.
 * @arg qdisc           Netem qdisc to be modified.
 * @arg gap             New gap in number of packets.
 * @return 0 on success or a negative error code.
 */
void rtnl_netem_set_gap(struct rtnl_qdisc *qdisc, int gap)
{
        struct rtnl_netem *netem;
 
        if (!(netem = rtnl_tc_data(TC_CAST(qdisc))))
                BUG();
 
        netem->qnm_gap = gap;
        netem->qnm_mask |= SCH_NETEM_ATTR_GAP;
}
 
/**
 * Get re-ordering gap of netem qdisc.
 * @arg qdisc           Netem qdisc.
 * @return Re-ordering gap in packets or a negative error code.
 */
int rtnl_netem_get_gap(struct rtnl_qdisc *qdisc)
{
        struct rtnl_netem *netem;
 
        if (!(netem = rtnl_tc_data(TC_CAST(qdisc))))
                return -NLE_NOMEM;
 
        if (netem->qnm_mask & SCH_NETEM_ATTR_GAP)
                return netem->qnm_gap;
        else
                return -NLE_NOATTR;
}
 
/**
 * Set re-ordering probability of netem qdisc.
 * @arg qdisc           Netem qdisc to be modified.
 * @arg prob            New re-ordering probability.
 * @return 0 on success or a negative error code.
 */
void rtnl_netem_set_reorder_probability(struct rtnl_qdisc *qdisc, int prob)
{
        struct rtnl_netem *netem;
 
        if (!(netem = rtnl_tc_data(TC_CAST(qdisc))))
                BUG();
 
        netem->qnm_ro.nmro_probability = prob;
        netem->qnm_mask |= SCH_NETEM_ATTR_RO_PROB;
}
 
/**
 * Get re-ordering probability of netem qdisc.
 * @arg qdisc           Netem qdisc.
 * @return Re-ordering probability or a negative error code.
 */
int rtnl_netem_get_reorder_probability(struct rtnl_qdisc *qdisc)
{
        struct rtnl_netem *netem;
 
        if (!(netem = rtnl_tc_data(TC_CAST(qdisc))))
                return -NLE_NOMEM;
 
        if (netem->qnm_mask & SCH_NETEM_ATTR_RO_PROB)
                return netem->qnm_ro.nmro_probability;
        else
                return -NLE_NOATTR;
}
 
/**
 * Set re-order correlation probability of netem qdisc.
 * @arg qdisc           Netem qdisc to be modified.
 * @arg prob            New re-ordering correlation probability.
 * @return 0 on success or a negative error code.
 */
void rtnl_netem_set_reorder_correlation(struct rtnl_qdisc *qdisc, int prob)
{
        struct rtnl_netem *netem;
 
        if (!(netem = rtnl_tc_data(TC_CAST(qdisc))))
                BUG();
 
        netem->qnm_ro.nmro_correlation = prob;
        netem->qnm_mask |= SCH_NETEM_ATTR_RO_CORR;
}
 
/**
 * Get re-ordering correlation probability of netem qdisc.
 * @arg qdisc           Netem qdisc.
 * @return Re-ordering correlation probability or a negative error code.
 */
int rtnl_netem_get_reorder_correlation(struct rtnl_qdisc *qdisc)
{
        struct rtnl_netem *netem;
 
        if (!(netem = rtnl_tc_data(TC_CAST(qdisc))))
                return -NLE_NOMEM;
 
        if (netem->qnm_mask & SCH_NETEM_ATTR_RO_CORR)
                return netem->qnm_ro.nmro_correlation;
        else
                return -NLE_NOATTR;
}
 
/** @} */
 
/**
 * @name Corruption
 * @{
 */
 
/**
 * Set corruption probability of netem qdisc.
 * @arg qdisc           Netem qdisc to be modified.
 * @arg prob            New corruption probability.
 * @return 0 on success or a negative error code.
 */
void rtnl_netem_set_corruption_probability(struct rtnl_qdisc *qdisc, int prob)
{
        struct rtnl_netem *netem;
 
        if (!(netem = rtnl_tc_data(TC_CAST(qdisc))))
                BUG();
 
        netem->qnm_crpt.nmcr_probability = prob;
        netem->qnm_mask |= SCH_NETEM_ATTR_CORRUPT_PROB;
}
 
/**
 * Get corruption probability of netem qdisc.
 * @arg qdisc           Netem qdisc.
 * @return Corruption probability or a negative error code.
 */
int rtnl_netem_get_corruption_probability(struct rtnl_qdisc *qdisc)
{
        struct rtnl_netem *netem;
 
        if (!(netem = rtnl_tc_data(TC_CAST(qdisc))))
                BUG();
 
        if (netem->qnm_mask & SCH_NETEM_ATTR_CORRUPT_PROB)
                return netem->qnm_crpt.nmcr_probability;
        else
                return -NLE_NOATTR;
}
 
/**
 * Set corruption correlation probability of netem qdisc.
 * @arg qdisc           Netem qdisc to be modified.
 * @arg prob            New corruption correlation probability.
 * @return 0 on success or a negative error code.
 */
void rtnl_netem_set_corruption_correlation(struct rtnl_qdisc *qdisc, int prob)
{
        struct rtnl_netem *netem;
 
        if (!(netem = rtnl_tc_data(TC_CAST(qdisc))))
                BUG();
 
        netem->qnm_crpt.nmcr_correlation = prob;
        netem->qnm_mask |= SCH_NETEM_ATTR_CORRUPT_CORR;
}
 
/**
 * Get corruption correlation probability of netem qdisc.
 * @arg qdisc           Netem qdisc.
 * @return Corruption correlation probability or a negative error code.
 */
int rtnl_netem_get_corruption_correlation(struct rtnl_qdisc *qdisc)
{
        struct rtnl_netem *netem;
 
        if (!(netem = rtnl_tc_data(TC_CAST(qdisc))))
                BUG();
 
        if (netem->qnm_mask & SCH_NETEM_ATTR_CORRUPT_CORR)
                return netem->qnm_crpt.nmcr_correlation;
        else
                return -NLE_NOATTR;
}
 
/** @} */
 
/**
 * @name Packet Loss
 * @{
 */
 
/**
 * Set packet loss probability of netem qdisc.
 * @arg qdisc           Netem qdisc to be modified.
 * @arg prob            New packet loss probability.
 * @return 0 on success or a negative error code.
 */
void rtnl_netem_set_loss(struct rtnl_qdisc *qdisc, int prob)
{
        struct rtnl_netem *netem;
 
        if (!(netem = rtnl_tc_data(TC_CAST(qdisc))))
                BUG();
 
        netem->qnm_loss = prob;
        netem->qnm_mask |= SCH_NETEM_ATTR_LOSS;
}
 
/**
 * Get packet loss probability of netem qdisc.
 * @arg qdisc           Netem qdisc.
 * @return Packet loss probability or a negative error code.
 */
int rtnl_netem_get_loss(struct rtnl_qdisc *qdisc)
{
        struct rtnl_netem *netem;
 
        if (!(netem = rtnl_tc_data(TC_CAST(qdisc))))
                BUG();
 
        if (netem->qnm_mask & SCH_NETEM_ATTR_LOSS)
                return netem->qnm_loss;
        else
                return -NLE_NOATTR;
}
 
/**
 * Set packet loss correlation probability of netem qdisc.
 * @arg qdisc           Netem qdisc to be modified.
 * @arg prob    New packet loss correlation.
 * @return 0 on success or a negative error code.
 */
void rtnl_netem_set_loss_correlation(struct rtnl_qdisc *qdisc, int prob)
{
        struct rtnl_netem *netem;
 
        if (!(netem = rtnl_tc_data(TC_CAST(qdisc))))
                BUG();
 
        netem->qnm_corr.nmc_loss = prob;
        netem->qnm_mask |= SCH_NETEM_ATTR_LOSS_CORR;
}
 
/**
 * Get packet loss correlation probability of netem qdisc.
 * @arg qdisc           Netem qdisc.
 * @return Packet loss correlation probability or a negative error code.
 */
int rtnl_netem_get_loss_correlation(struct rtnl_qdisc *qdisc)
{
        struct rtnl_netem *netem;
 
        if (!(netem = rtnl_tc_data(TC_CAST(qdisc))))
                BUG();
 
        if (netem->qnm_mask & SCH_NETEM_ATTR_LOSS_CORR)
                return netem->qnm_corr.nmc_loss;
        else
                return -NLE_NOATTR;
}
 
/** @} */
 
/**
 * @name Packet Duplication
 * @{
 */
 
/**
 * Set packet duplication probability of netem qdisc.
 * @arg qdisc           Netem qdisc to be modified.
 * @arg prob    New packet duplication probability.
 * @return 0 on success or a negative error code.
 */
void rtnl_netem_set_duplicate(struct rtnl_qdisc *qdisc, int prob)
{
        struct rtnl_netem *netem;
 
        if (!(netem = rtnl_tc_data(TC_CAST(qdisc))))
                BUG();
 
        netem->qnm_duplicate = prob;
        netem->qnm_mask |= SCH_NETEM_ATTR_DUPLICATE;
}
 
/**
 * Get packet duplication probability of netem qdisc.
 * @arg qdisc           Netem qdisc.
 * @return Packet duplication probability or a negative error code.
 */
int rtnl_netem_get_duplicate(struct rtnl_qdisc *qdisc)
{
        struct rtnl_netem *netem;
 
        if (!(netem = rtnl_tc_data(TC_CAST(qdisc))))
                BUG();
 
        if (netem->qnm_mask & SCH_NETEM_ATTR_DUPLICATE)
                return netem->qnm_duplicate;
        else
                return -NLE_NOATTR;
}
 
/**
 * Set packet duplication correlation probability of netem qdisc.
 * @arg qdisc           Netem qdisc to be modified.
 * @arg prob            New packet duplication correlation probability.
 * @return 0 on success or a negative error code.
 */
void rtnl_netem_set_duplicate_correlation(struct rtnl_qdisc *qdisc, int prob)
{
        struct rtnl_netem *netem;
 
        if (!(netem = rtnl_tc_data(TC_CAST(qdisc))))
                BUG();
 
        netem->qnm_corr.nmc_duplicate = prob;
        netem->qnm_mask |= SCH_NETEM_ATTR_DUP_CORR;
}
 
/**
 * Get packet duplication correlation probability of netem qdisc.
 * @arg qdisc           Netem qdisc.
 * @return Packet duplication correlation probability or a negative error code.
 */
int rtnl_netem_get_duplicate_correlation(struct rtnl_qdisc *qdisc)
{
        struct rtnl_netem *netem;
 
        if (!(netem = rtnl_tc_data(TC_CAST(qdisc))))
                BUG();
 
        if (netem->qnm_mask & SCH_NETEM_ATTR_DUP_CORR)
                return netem->qnm_corr.nmc_duplicate;
        else
                return -NLE_NOATTR;
}
 
/** @} */
 
/**
 * @name Packet Delay
 * @{
 */
 
/**
 * Set packet delay of netem qdisc.
 * @arg qdisc           Netem qdisc to be modified.
 * @arg delay           New packet delay in micro seconds.
 * @return 0 on success or a negative error code.
 */
void rtnl_netem_set_delay(struct rtnl_qdisc *qdisc, int delay)
{
        struct rtnl_netem *netem;
 
        if (!(netem = rtnl_tc_data(TC_CAST(qdisc))))
                BUG();
 
        netem->qnm_latency = nl_us2ticks(delay);
        netem->qnm_mask |= SCH_NETEM_ATTR_LATENCY;
}
 
/**
 * Get packet delay of netem qdisc.
 * @arg qdisc           Netem qdisc.
 * @return Packet delay in micro seconds or a negative error code.
 */
int rtnl_netem_get_delay(struct rtnl_qdisc *qdisc)
{
        struct rtnl_netem *netem;
 
        if (!(netem = rtnl_tc_data(TC_CAST(qdisc))))
                BUG();
 
        if (netem->qnm_mask & SCH_NETEM_ATTR_LATENCY)
                return nl_ticks2us(netem->qnm_latency);
        else
                return -NLE_NOATTR;
}
 
/**
 * Set packet delay jitter of netem qdisc.
 * @arg qdisc           Netem qdisc to be modified.
 * @arg jitter          New packet delay jitter in micro seconds.
 * @return 0 on success or a negative error code.
 */
void rtnl_netem_set_jitter(struct rtnl_qdisc *qdisc, int jitter)
{
        struct rtnl_netem *netem;
 
        if (!(netem = rtnl_tc_data(TC_CAST(qdisc))))
                BUG();
 
        netem->qnm_jitter = nl_us2ticks(jitter);
        netem->qnm_mask |= SCH_NETEM_ATTR_JITTER;
}
 
/**
 * Get packet delay jitter of netem qdisc.
 * @arg qdisc           Netem qdisc.
 * @return Packet delay jitter in micro seconds or a negative error code.
 */
int rtnl_netem_get_jitter(struct rtnl_qdisc *qdisc)
{
        struct rtnl_netem *netem;
 
        if (!(netem = rtnl_tc_data(TC_CAST(qdisc))))
                BUG();
 
        if (netem->qnm_mask & SCH_NETEM_ATTR_JITTER)
                return nl_ticks2us(netem->qnm_jitter);
        else
                return -NLE_NOATTR;
}
 
/**
 * Set packet delay correlation probability of netem qdisc.
 * @arg qdisc           Netem qdisc to be modified.
 * @arg prob            New packet delay correlation probability.
 */
void rtnl_netem_set_delay_correlation(struct rtnl_qdisc *qdisc, int prob)
{
        struct rtnl_netem *netem;
 
        if (!(netem = rtnl_tc_data(TC_CAST(qdisc))))
                BUG();
 
        netem->qnm_corr.nmc_delay = prob;
        netem->qnm_mask |= SCH_NETEM_ATTR_DELAY_CORR;
}
 
/**
 * Get packet delay correlation probability of netem qdisc.
 * @arg qdisc           Netem qdisc.
 * @return Packet delay correlation probability or a negative error code.
 */
int rtnl_netem_get_delay_correlation(struct rtnl_qdisc *qdisc)
{
        struct rtnl_netem *netem;
 
        if (!(netem = rtnl_tc_data(TC_CAST(qdisc))))
                BUG();
 
        if (netem->qnm_mask & SCH_NETEM_ATTR_DELAY_CORR)
                return netem->qnm_corr.nmc_delay;
        else
                return -NLE_NOATTR;
}
 
/**
 * Get the size of the distribution table.
 * @arg qdisc           Netem qdisc.
 * @return Distribution table size or a negative error code.
 */
int rtnl_netem_get_delay_distribution_size(struct rtnl_qdisc *qdisc)
{
        struct rtnl_netem *netem;
 
        if (!(netem = rtnl_tc_data(TC_CAST(qdisc))))
                BUG();
 
        if (netem->qnm_mask & SCH_NETEM_ATTR_DIST)
                return netem->qnm_dist.dist_size;
        else
                return -NLE_NOATTR;
}
 
/**
 * Get a pointer to the distribution table.
 * @arg qdisc           Netem qdisc.
 * @arg dist_ptr        The pointer to set.
 * @return Negative error code on failure or 0 on success.
 */
int rtnl_netem_get_delay_distribution(struct rtnl_qdisc *qdisc, int16_t **dist_ptr)
{
        struct rtnl_netem *netem;
 
        if (!(netem = rtnl_tc_data(TC_CAST(qdisc))))
                BUG();
 
        if (netem->qnm_mask & SCH_NETEM_ATTR_DIST) {
                *dist_ptr = netem->qnm_dist.dist_data;
                return 0;
        } else
                return -NLE_NOATTR;
}
 
/**
 * Set the delay distribution data. Latency/jitter must be set before applying.
 * @arg qdisc Netem qdisc.
 * @return 0 on success, error code on failure.
 */
int rtnl_netem_set_delay_distribution_data(struct rtnl_qdisc *qdisc, const int16_t *data, size_t len) {
        struct rtnl_netem *netem;
        int16_t *new_data;
 
        if (!(netem = rtnl_tc_data(TC_CAST(qdisc))))
                BUG();
 
        if (len > MAXDIST)
                return -NLE_INVAL;
 
        new_data = (int16_t *) calloc(len, sizeof(int16_t));
        if (!new_data)
                return -NLE_NOMEM;
 
        free (netem->qnm_dist.dist_data);
        netem->qnm_dist.dist_data = new_data;
 
        memcpy(netem->qnm_dist.dist_data, data, len * sizeof(int16_t));
 
        netem->qnm_dist.dist_size = len;
        netem->qnm_mask |= SCH_NETEM_ATTR_DIST;
 
        return 0;
}
 
/**
 * Load the delay distribution from a file. Latency/jitter must be set before applying.
 * @arg qdisc Netem qdisc.
 * @arg dist_type The name of the distribution (type, file, path/file).
 * @return 0 on success, error code on failure.
 */
int rtnl_netem_set_delay_distribution(struct rtnl_qdisc *qdisc, const char *dist_type) {
        FILE *f;
        int n = 0;
        size_t i;
        size_t len = 2048;
        _nl_auto_free char *line = NULL;
        char name[NAME_MAX];
        char dist_suffix[] = ".dist";
        _nl_auto_free int16_t *data = NULL;
        char *test_suffix;
 
        /* Check several locations for the dist file */
        char *test_path[] = {
                "",
                "./",
                "/usr/lib/tc/",
                "/usr/lib64/tc/",
                "/usr/local/lib/tc/",
        };
 
        /* If the given filename already ends in .dist, don't append it later */
        test_suffix = strstr(dist_type, dist_suffix);
        if (test_suffix != NULL && strlen(test_suffix) == 5)
                strcpy(dist_suffix, "");
 
        for (i = 0; i < ARRAY_SIZE(test_path); i++) {
                snprintf(name, NAME_MAX, "%s%s%s", test_path[i], dist_type, dist_suffix);
                if ((f = fopen(name, "re")))
                        break;
        }
 
        if (f == NULL)
                return -nl_syserr2nlerr(errno);
 
        data = (int16_t *) calloc(MAXDIST, sizeof(int16_t));
        line = (char *) calloc(sizeof(char), len + 1);
        if (!data || !line) {
            fclose(f);
            return -NLE_NOMEM;
        }
 
        while (getline(&line, &len, f) != -1) {
                char *p, *endp;
 
                if (*line == '\n' || *line == '#')
                        continue;
 
                for (p = line; ; p = endp) {
                        long x = strtol(p, &endp, 0);
                        if (endp == p) break;
 
                        if (n >= MAXDIST) {
                                fclose(f);
                                return -NLE_INVAL;
                        }
                        data[n++] = x;
                }
        }
 
        fclose(f);
        i = rtnl_netem_set_delay_distribution_data(qdisc, data, n);
        return i;
}
 
/** @} */
 
static struct rtnl_tc_ops netem_ops = {
        .to_kind                = "netem",
        .to_type                = RTNL_TC_TYPE_QDISC,
        .to_size                = sizeof(struct rtnl_netem),
        .to_msg_parser          = netem_msg_parser,
        .to_free_data           = netem_free_data,
        .to_dump[NL_DUMP_LINE]  = netem_dump_line,
        .to_dump[NL_DUMP_DETAILS] = netem_dump_details,
        .to_msg_fill_raw        = netem_msg_fill_raw,
};
 
static void __init netem_init(void)
{
        rtnl_tc_register(&netem_ops);
}
 
static void __exit netem_exit(void)
{
        rtnl_tc_unregister(&netem_ops);
}
 
/** @} */