rlim qdisc support

Add support for new rate limit qdisc
Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>

tc/q_rlim.c

+/*
+ * q_rtlim.c		RTLIM.
+ *
+ *		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:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
+ *
+ */
+
+#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: ... rlim limit PACKETS rate KBPS [ overhead BYTES ]\n");
+}
+
+static void explain1(char *arg)
+{
+	fprintf(stderr, "Illegal \"%s\"\n", arg);
+}
+
+
+#define usage() return(-1)
+
+static int rlim_parse_opt(struct qdisc_util *qu, int argc, char **argv, struct nlmsghdr *n)
+{
+	unsigned x;
+	struct tc_rlim_qopt opt = { 
+		.overhead = 24,		/* Ether IPG + Preamble + CRC */
+	};
+	struct rtattr *tail;
+
+	while (argc > 0) {
+		if (matches(*argv, "limit") == 0) {
+			NEXT_ARG();
+			if (opt.limit) {
+				fprintf(stderr, "Double \"limit\" spec\n");
+				return -1;
+			}
+			if (get_size(&opt.limit, *argv)) {
+				explain1("limit");
+				return -1;
+			}
+		} else if (strcmp(*argv, "rate") == 0) {
+			NEXT_ARG();
+			if (opt.rate) {
+				fprintf(stderr, "Double \"rate\" spec\n");
+				return -1;
+			}
+
+			if (get_rate(&x, *argv)) {
+				explain1("rate");
+				return -1;
+			}
+			opt.rate = x;
+		} else if (strcmp(*argv, "help") == 0) {
+			explain();
+			return -1;
+		} else {
+			fprintf(stderr, "What is \"%s\"?\n", *argv);
+			explain();
+			return -1;
+		}
+		argc--; argv++;
+	}
+
+	if (opt.rate == 0) {
+		fprintf(stderr, "\"rate\" is required.\n");
+		return -1;
+	}
+
+	if (opt.limit == 0)
+		opt.limit = 1000;
+
+	tail = NLMSG_TAIL(n);
+	addattr_l(n, 1024, TCA_OPTIONS, NULL, 0);
+	addattr_l(n, 2024, TCA_RLIM_PARMS, &opt, sizeof(opt));
+	tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail;
+
+	return 0;
+}
+
+static int rlim_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
+{
+	struct rtattr *tb[TCA_RLIM_PARMS+1];
+	struct tc_rlim_qopt *qopt;
+	SPRINT_BUF(b1);
+	SPRINT_BUF(b2);
+
+	if (opt == NULL)
+		return 0;
+
+	parse_rtattr_nested(tb, TCA_RLIM_PARMS, opt);
+	if (tb[TCA_RLIM_PARMS] == NULL)
+		return -1;
+
+	qopt = RTA_DATA(tb[TCA_RLIM_PARMS]);
+	if (RTA_PAYLOAD(tb[TCA_RLIM_PARMS])  < sizeof(*qopt))
+		return -1;
+
+	fprintf(f, "limit %s rate %s overhead %u", 
+		sprint_size(qopt->limit, b1),
+		sprint_rate(qopt->rate, b2),
+		qopt->overhead);
+
+	return 0;
+}
+
+struct qdisc_util rlim_qdisc_util = {
+	.id		= "rlim",
+	.parse_qopt	= rlim_parse_opt,
+	.print_qopt	= rlim_print_opt,
+};
+