int netem_set_params(const char *iface, struct netem_params *params)
{
struct rtnl_link *link;
struct rtnl_qdisc *qdisc;
int err;
pthread_mutex_lock(&nl_sock_mutex);
/* filter link by name */
if ((link = rtnl_link_get_by_name(link_cache, iface)) == NULL) {
fprintf(stderr, "unknown interface/link name.\n");
pthread_mutex_unlock(&nl_sock_mutex);
return -1;
}
if (!(qdisc = rtnl_qdisc_alloc())) {
/* OOM error */
fprintf(stderr, "couldn't alloc qdisc\n");
pthread_mutex_unlock(&nl_sock_mutex);
return -1;
}
rtnl_tc_set_link(TC_CAST(qdisc), link);
rtnl_tc_set_parent(TC_CAST(qdisc), TC_H_ROOT);
rtnl_tc_set_kind(TC_CAST(qdisc), "netem");
rtnl_netem_set_delay(qdisc,
params->delay * 1000); /* expects microseconds */
rtnl_netem_set_jitter(qdisc, params->jitter * 1000);
/* params->loss is given in 10ths of a percent */
rtnl_netem_set_loss(qdisc, (params->loss * (UINT_MAX / 1000)));
/* Submit request to kernel and wait for response */
err = rtnl_qdisc_add(sock, qdisc, NLM_F_CREATE | NLM_F_REPLACE);
/* Return the qdisc object to free memory resources */
rtnl_qdisc_put(qdisc);
if (err < 0) {
fprintf(stderr, "Unable to add qdisc: %s\n", nl_geterror(err));
pthread_mutex_unlock(&nl_sock_mutex);
return err;
}
if ((err = nl_cache_refill(sock, link_cache)) < 0) {
fprintf(stderr, "Unable to resync link cache: %s\n",
nl_geterror(err));
pthread_mutex_unlock(&nl_sock_mutex);
return -1;
}
pthread_mutex_unlock(&nl_sock_mutex);
return 0;
}
static int dist_load(int argc, char *argv[])
{
FILE *fp;
double mu, sigma, rho;
if (argc == 1) {
if (!(fp = fopen(argv[0], "r")))
error(-1, errno, "Failed to open file: %s", argv[0]);
}
else
fp = stdin;
short *inverse = dist_make(fp, &mu, &sigma, &rho);
if (!inverse)
error(-1, 0, "Failed to generate distribution");
int ret;
struct nl_sock *sock;
struct rtnl_link *link;
struct rtnl_tc *qdisc_prio = NULL;
struct rtnl_tc *qdisc_netem = NULL;
struct rtnl_tc *cls_fw = NULL;
/* Create connection to netlink */
sock = nl_socket_alloc();
nl_connect(sock, NETLINK_ROUTE);
/* Get interface */
link = tc_get_link(sock, cfg.dev);
if (!link)
error(-1, 0, "Interface does not exist: %s", cfg.dev);
/* Reset TC subsystem */
ret = tc_reset(sock, link);
if (ret && ret != -NLE_OBJ_NOTFOUND)
error(-1, 0, "Failed to reset TC: %s", nl_geterror(ret));
/* Setup TC subsystem */
if ((ret = tc_prio(sock, link, &qdisc_prio)))
error(-1, 0, "Failed to setup TC: prio qdisc: %s", nl_geterror(ret));
if ((ret = tc_classifier(sock, link, &cls_fw, cfg.mark, cfg.mask)))
error(-1, 0, "Failed to setup TC: fw filter: %s", nl_geterror(ret));
if ((ret = tc_netem(sock, link, &qdisc_netem)))
error(-1, 0, "Failed to setup TC: netem qdisc: %s", nl_geterror(ret));
/* We will use the default normal distribution for now */
if (rtnl_netem_set_delay_distribution_data((struct rtnl_qdisc *) qdisc_netem, inverse, TABLESIZE))
error(-1, 0, "Failed to set netem delay distrubtion: %s", nl_geterror(ret));
rtnl_netem_set_delay((struct rtnl_qdisc *) qdisc_netem, mu);
rtnl_netem_set_jitter((struct rtnl_qdisc *) qdisc_netem, sigma);
nl_close(sock);
nl_socket_free(sock);
return 0;
}