tc/q_netem.c

/*
 * q_netem.c		NETEM.
 *
 *		This program is free software; you can redistribute it and/or
 *		modify it under the terms of the GNU General Public License
 *		as published by the Free Software Foundation; either version
 *		2 of the License, or (at your option) any later version.
 *
 * Authors:	Stephen Hemminger <shemminger@osdl.org>
 *
 */

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <syslog.h>
#include <fcntl.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <string.h>

#include "utils.h"
#include "tc_util.h"

static void explain(void)
{
	fprintf(stderr, 
"Usage: ... netem latency TIME [ jitter TIME ] [ limit PACKETS] \n" \
"                 [ loss PERCENT ] [ duplicate PERCENT ]\n" \
"                 [ gap PACKETS]\n");
}

static void explain1(const char *arg)
{
	fprintf(stderr, "Illegal \"%s\"\n", arg);
}

#define usage() return(-1)

static int netem_parse_opt(struct qdisc_util *qu, int argc, char **argv, 
			   struct nlmsghdr *n)
{
	struct tc_netem_qopt opt;
	unsigned latency = 0;
	int ok = 0;

	memset(&opt, 0, sizeof(opt));
	opt.limit = 1000;

	while (argc > 0) {
		if (matches(*argv, "limit") == 0) {
			NEXT_ARG();
			if (get_size(&opt.limit, *argv)) {
				explain1("limit");
				return -1;
			}
			ok++;
		} else if (matches(*argv, "latency") == 0) {
			NEXT_ARG();
			if (get_usecs(&latency, *argv)) {
				explain1("latency");
				return -1;
			}
			ok++;
		} else if (matches(*argv, "loss") == 0) {
			NEXT_ARG();
			if (get_percent(&opt.loss, *argv)) {
				explain1("loss");
				return -1;
			}
			ok++;
		} else if (matches(*argv, "gap") == 0) {
			NEXT_ARG();
			if (get_u32(&opt.gap, *argv, 0)) {
				explain1("gap");
				return -1;
			}
			ok++;
		} else if (matches(*argv, "duplicate") == 0) {
			NEXT_ARG();
			if (get_percent(&opt.duplicate, *argv)) {
				explain1("duplicate");
				return -1;
			}
			ok++;
		} else if (matches(*argv, "jitter") == 0) {
			NEXT_ARG();
			if (get_usecs(&opt.jitter, *argv)) {
				explain1("jitter");
				return -1;
			}
			ok++;
		} else if (strcmp(*argv, "help") == 0) {
			explain();
			return -1;
		} else {
			fprintf(stderr, "What is \"%s\"?\n", *argv);
			explain();
			return -1;
		}
		argc--; argv++;
	}

	opt.latency = tc_core_usec2tick(latency);

	return ok ? addattr_l(n, 1024, TCA_OPTIONS, &opt, sizeof(opt)) : 0;
}

static int netem_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
{
	struct tc_netem_qopt *qopt;
	SPRINT_BUF(b1);

	if (opt == NULL)
		return 0;

	if (RTA_PAYLOAD(opt)  < sizeof(*qopt))
		return -1;

	qopt = RTA_DATA(opt);

	fprintf(f, "limit %d", qopt->limit);
	if (qopt->latency)
		fprintf(f, " latency %s", 
			sprint_usecs(tc_core_tick2usec(qopt->latency), b1));
	if (qopt->jitter)
		fprintf(f, " jitter %s", sprint_usecs(qopt->jitter, b1));

	if (qopt->loss)
		fprintf(f, " loss %s",
			sprint_percent(qopt->loss, b1));
	if (qopt->gap)
		fprintf(f, " gap %lu", (unsigned long)qopt->gap);


	return 0;
}

static int netem_print_xstats(struct qdisc_util *qu, FILE *f, struct rtattr *xstats)
{
	return 0;
}

struct qdisc_util netem_util = {
	.id	   	= "netem",
	.parse_qopt	= netem_parse_opt,
	.print_qopt	= netem_print_opt,
	.print_xstats	= netem_print_xstats,
};