Module for ip utility to support veth device (v.2.1)

The usage is
# ip link add [name] type veth [peer <name>] [mac <mac>] [peer_mac <mac>]

This version doesn't include the fix for ip/iplink.c as Patrick
said that he had included it into his patches already.
Signed-off-by: Pavel Emelianov <xemul@openvz.org>
Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>

ip/Makefile

@@ -10,8 +10,9 @@ RTMONOBJ=rtmon.o
 ALLOBJ=$(IPOBJ) $(RTMONOBJ)
 SCRIPTS=ifcfg rtpr routel routef
 TARGETS=ip rtmon
+LIBS=link_veth.so
 
-all: $(TARGETS) $(SCRIPTS)
+all: $(TARGETS) $(SCRIPTS) $(LIBS)
 
 ip: $(IPOBJ) $(LIBNETLINK) $(LIBUTIL)
 
@@ -26,3 +27,6 @@ clean:
 
 LDLIBS	+= -ldl
 LDFLAGS	+= -Wl,-export-dynamic
+
+%.so: %.c
+	$(CC) $(CFLAGS) -shared $< -o $@

ip/link_veth.c

+/*
+ * link_veth.c	veth driver module
+ *
+ *		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:	Pavel Emelianov <xemul@openvz.org>
+ *
+ */
+
+#include <string.h>
+
+#include "utils.h"
+#include "ip_common.h"
+#include "veth.h"
+
+#define ETH_ALEN	6
+
+static void usage(void)
+{
+	printf("Usage: ip link add ... type veth "
+			"[peer <peer-name>] [mac <mac>] [peer_mac <mac>]\n");
+}
+
+static int veth_parse_opt(struct link_util *lu, int argc, char **argv,
+		struct nlmsghdr *hdr)
+{
+	__u8 mac[ETH_ALEN];
+
+	for (; argc != 0; argv++, argc--) {
+		if (strcmp(*argv, "peer") == 0) {
+			argv++;
+			argc--;
+			if (argc == 0) {
+				usage();
+				return -1;
+			}
+
+			addattr_l(hdr, 1024, VETH_INFO_PEER,
+					*argv, strlen(*argv));
+
+			continue;
+		}
+
+		if (strcmp(*argv, "mac") == 0) {
+			argv++;
+			argc--;
+			if (argc == 0) {
+				usage();
+				return -1;
+			}
+
+			if (hexstring_a2n(*argv, mac, sizeof(mac)) == NULL)
+				return -1;
+
+			addattr_l(hdr, 1024, VETH_INFO_MAC,
+					mac, ETH_ALEN);
+			continue;
+		}
+
+		if (strcmp(*argv, "peer_mac") == 0) {
+			argv++;
+			argc--;
+			if (argc == 0) {
+				usage();
+				return -1;
+			}
+
+			if (hexstring_a2n(*argv, mac, sizeof(mac)) == NULL)
+				return -1;
+
+			addattr_l(hdr, 1024, VETH_INFO_PEER_MAC,
+					mac, ETH_ALEN);
+			continue;
+		}
+
+		usage();
+		return -1;
+	}
+
+	return 0;
+}
+
+struct link_util veth_link_util = {
+	.id = "veth",
+	.parse_opt = veth_parse_opt,
+};

ip/veth.h

+#ifndef __NET_VETH_H__
+#define __NET_VETH_H__
+
+enum {
+	VETH_INFO_UNSPEC,
+	VETH_INFO_MAC,
+	VETH_INFO_PEER,
+	VETH_INFO_PEER_MAC,
+
+	__VETH_INFO_MAX
+#define VETH_INFO_MAX	(__VETH_INFO_MAX - 1)
+};
+
+#endif