iproute2: tc add mqprio qdisc support

Add mqprio qdisc support. Output matches the following,

qdisc mq 0: dev eth1 root
qdisc mq 0: dev eth2 root
qdisc mqprio 8001: dev eth3 root  tc 8 map 0 1 2 3 4 5 6 7 1 1 1 1 1 1 1 1
             queues:(0:7) (8:15) (16:23) (24:31) (32:39) (40:47) (48:55) (56:63)

And usage is,

Usage: ... mclass [num_tc NUMBER] [map P0 P1...]
                  [offset txq0 txq1 ...] [count cnt0 cnt1 ...] [hw 1|0]
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>

tc/Makefile

@@ -45,6 +45,7 @@ TCMODULES += em_nbyte.o
 TCMODULES += em_cmp.o
 TCMODULES += em_u32.o
 TCMODULES += em_meta.o
+TCMODULES += q_mqprio.o
 
 TCSO :=
 ifeq ($(TC_CONFIG_ATM),y)

tc/q_mqprio.c

+/*
+ * q_mqprio.c	MQ prio qdisc
+ *
+ *		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.
+ *
+ * Author:	John Fastabend, <john.r.fastabend@intel.com>
+ */
+
+#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: ... mqprio [num_tc NUMBER] [map P0 P1 ...]\n");
+	fprintf(stderr, "                  [offset txq0 txq1 ...] ");
+	fprintf(stderr, "[count cnt0,cnt1 ...] [hw 1|0]\n");
+}
+
+static int mqprio_parse_opt(struct qdisc_util *qu, int argc,
+			    char **argv, struct nlmsghdr *n)
+{
+	int idx;
+	struct tc_mqprio_qopt opt = {
+				     8,
+				     {0, 1, 2, 3, 4, 5, 6, 7, 0, 1, 1, 1, 3, 3, 3, 3},
+				     1,
+				    };
+
+	while (argc > 0) {
+		idx = 0;
+		if (strcmp(*argv, "num_tc") == 0) {
+			NEXT_ARG();
+			if (get_u8(&opt.num_tc, *argv, 10)) {
+				fprintf(stderr, "Illegal \"num_tc\"\n");
+				return -1;
+			}
+		} else if (strcmp(*argv, "map") == 0) {
+			while (idx < TC_QOPT_MAX_QUEUE && NEXT_ARG_OK()) {
+				NEXT_ARG();
+				if (get_u8(&opt.prio_tc_map[idx], *argv, 10)) {
+					PREV_ARG();
+					break;
+				}
+				idx++;
+			}
+			for ( ; idx < TC_QOPT_MAX_QUEUE; idx++)
+				opt.prio_tc_map[idx] = 0;
+		} else if (strcmp(*argv, "offset") == 0) {
+			while (idx < TC_QOPT_MAX_QUEUE && NEXT_ARG_OK()) {
+				NEXT_ARG();
+				if (get_u16(&opt.offset[idx], *argv, 10)) {
+					PREV_ARG();
+					break;
+				}
+				idx++;
+			}
+		} else if (strcmp(*argv, "count") == 0) {
+			while (idx < TC_QOPT_MAX_QUEUE && NEXT_ARG_OK()) {
+				NEXT_ARG();
+				if (get_u16(&opt.count[idx], *argv, 10)) {
+					PREV_ARG();
+					break;
+				}
+				idx++;
+			}
+		} else if (strcmp(*argv, "hw") == 0) {
+			NEXT_ARG();
+			if (get_u8(&opt.hw, *argv, 10)) {
+				fprintf(stderr, "Illegal \"hw\"\n");
+				return -1;
+			}
+			idx++;
+		} else if (strcmp(*argv, "help") == 0) {
+			explain();
+			return -1;
+		} else {
+			fprintf(stderr, "Unknown argument\n");
+			return -1;
+		}
+		argc--; argv++;
+	}
+
+	addattr_l(n, 1024, TCA_OPTIONS, &opt, sizeof(opt));
+	return 0;
+}
+
+int mqprio_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
+{
+	int i;
+	struct tc_mqprio_qopt *qopt;
+
+	if (opt == NULL)
+		return 0;
+
+	qopt = RTA_DATA(opt);
+
+	fprintf(f, " tc %u map ", qopt->num_tc);
+	for (i = 0; i <= TC_PRIO_MAX; i++)
+		fprintf(f, "%d ", qopt->prio_tc_map[i]);
+	fprintf(f, "\n             queues:");
+	for (i = 0; i < qopt->num_tc; i++)
+		fprintf(f, "(%i:%i) ", qopt->offset[i],
+			qopt->offset[i] + qopt->count[i] - 1);
+	return 0;
+}
+
+struct qdisc_util mqprio_qdisc_util = {
+	.id		= "mqprio",
+	.parse_qopt	= mqprio_parse_opt,
+	.print_qopt	= mqprio_print_opt,
+};