add support for VRF device

Allow user to create a vrf device and specify its table binding.
Based on the iplink_vlan implementation.
Signed-off-by: Shrijeet Mukherjee <shm@cumulusnetworks.com>
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>

ip/Makefile

@@ -7,7 +7,7 @@ IPOBJ=ip.o ipaddress.o ipaddrlabel.o iproute.o iprule.o ipnetns.o \
     iplink_vxlan.o tcp_metrics.o iplink_ipoib.o ipnetconf.o link_ip6tnl.o \
     link_iptnl.o link_gre6.o iplink_bond.o iplink_bond_slave.o iplink_hsr.o \
     iplink_bridge.o iplink_bridge_slave.o ipfou.o iplink_ipvlan.o \
-    iplink_geneve.o
+    iplink_geneve.o iplink_vrf.o
 
 RTMONOBJ=rtmon.o
 

ip/iplink.c

@@ -94,7 +94,7 @@ void iplink_usage(void)
 		fprintf(stderr, "TYPE := { vlan | veth | vcan | dummy | ifb | macvlan | macvtap |\n");
 		fprintf(stderr, "          bridge | bond | ipoib | ip6tnl | ipip | sit | vxlan |\n");
 		fprintf(stderr, "          gre | gretap | ip6gre | ip6gretap | vti | nlmon |\n");
-		fprintf(stderr, "          bond_slave | ipvlan | geneve | bridge_slave }\n");
+		fprintf(stderr, "          bond_slave | ipvlan | geneve | bridge_slave | vrf }\n");
 	}
 	exit(-1);
 }

ip/iplink_vrf.c

+/* iplink_vrf.c	VRF device support
+ *
+ *              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:     Shrijeet Mukherjee <shm@cumulusnetworks.com>
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <linux/if_link.h>
+
+#include "rt_names.h"
+#include "utils.h"
+#include "ip_common.h"
+
+static void vrf_explain(FILE *f)
+{
+	fprintf(f, "Usage: ... vrf table TABLEID \n");
+}
+
+static void explain(void)
+{
+	vrf_explain(stderr);
+}
+
+static int table_arg(void)
+{
+	fprintf(stderr,"Error: argument of \"table\" must be 0-32767 and currently unused\n");
+	return -1;
+}
+
+static int vrf_parse_opt(struct link_util *lu, int argc, char **argv,
+			    struct nlmsghdr *n)
+{
+	while (argc > 0) {
+		if (matches(*argv, "table") == 0) {
+			__u32 table;
+
+			NEXT_ARG();
+
+			table = atoi(*argv);
+			if (table > 32767)
+				return table_arg();
+			addattr32(n, 1024, IFLA_VRF_TABLE, table);
+		} else if (matches(*argv, "help") == 0) {
+			explain();
+			return -1;
+		} else {
+			fprintf(stderr, "vrf: unknown option \"%s\"?\n",
+				*argv);
+			explain();
+			return -1;
+		}
+		argc--, argv++;
+	}
+
+	return 0;
+}
+
+static void vrf_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[])
+{
+	if (!tb)
+		return;
+
+	if (tb[IFLA_VRF_TABLE])
+		fprintf(f, "table %u ", rta_getattr_u32(tb[IFLA_VRF_TABLE]));
+}
+
+static void vrf_print_help(struct link_util *lu, int argc, char **argv,
+			      FILE *f)
+{
+	vrf_explain(f);
+}
+
+struct link_util vrf_link_util = {
+	.id		= "vrf",
+	.maxattr	= IFLA_VRF_MAX,
+	.parse_opt	= vrf_parse_opt,
+	.print_opt	= vrf_print_opt,
+	.print_help	= vrf_print_help,
+};