add support for multiq qdisc

Add support for multiq qdisc
	This patch adds the ability to configure the multiq qdisc.  Since the qdisc does not require any input it will pull the number of bands directly from the device that it is added to the root of.

usage: tc qdisc add dev <DEV> root handle <HANDLE> multiq
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

tc/Makefile

@@ -12,6 +12,7 @@ TCMODULES += q_prio.o
 TCMODULES += q_tbf.o
 TCMODULES += q_cbq.o
 TCMODULES += q_rr.o
+TCMODULES += q_multiq.o
 TCMODULES += q_netem.o
 TCMODULES += f_rsvp.o
 TCMODULES += f_u32.o

tc/q_multiq.c

+/*
+ * q_multiq.c		Multiqueue aware qdisc
+ *
+ * Copyright (c) 2008, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
+ * Place - Suite 330, Boston, MA 02111-1307 USA.
+ *
+ * Author: Alexander Duyck <alexander.h.duyck@intel.com>
+ *
+ * Original Authors:	PJ Waskiewicz, <peter.p.waskiewicz.jr@intel.com> (RR)
+ * 			Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> (from PRIO)
+ *
+ */
+
+#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: ... multiq [help]\n");
+}
+
+#define usage() return(-1)
+
+static int multiq_parse_opt(struct qdisc_util *qu, int argc, char **argv,
+			    struct nlmsghdr *n)
+{
+	struct tc_multiq_qopt opt;
+
+	if (argc > 0) {
+		if (strcmp(*argv, "help") == 0) {
+			explain();
+			return -1;
+		} else {
+			fprintf(stderr, "What is \"%s\"?\n", *argv);
+			explain();
+			return -1;
+		}
+		argc--; argv++;
+	}
+
+	addattr_l(n, 1024, TCA_OPTIONS, &opt, sizeof(opt));
+	return 0;
+}
+
+int multiq_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
+{
+	struct tc_multiq_qopt *qopt;
+
+	if (opt == NULL)
+		return 0;
+	if (RTA_PAYLOAD(opt) < sizeof(*qopt))
+		return 0;
+
+	qopt = RTA_DATA(opt);
+
+	fprintf(f, "bands %u/%u ", qopt->bands, qopt->max_bands);
+
+	return 0;
+}
+
+struct qdisc_util multiq_qdisc_util = {
+	.id	 	= "multiq",
+	.parse_qopt	= multiq_parse_opt,
+	.print_qopt	= multiq_print_opt,
+};