[PATCH iproute2 v2] vxlan: Allow setting destination to unicast address.

[Atzm Watanabe <atzm@stratosphere.co.jp>]

This patch allows setting VXLAN destination to unicast address.
It allows that VXLAN can be used as peer-to-peer tunnel without
multicast.

v2: use a new argument "remote" instead of "group" based by
    Stephen Hemminger's comments.

Signed-off-by: Atzm Watanabe <atzm@stratosphere.co.jp>
---
 include/linux/if_link.h |  1 +
 ip/iplink_vxlan.c       | 25 +++++++++++++++++++++++--
 2 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/include/linux/if_link.h b/include/linux/if_link.h
index 40167af..0bf03dc 100644
--- a/include/linux/if_link.h
+++ b/include/linux/if_link.h
@@ -296,6 +296,7 @@ enum {
 	IFLA_VXLAN_GROUP,
 	IFLA_VXLAN_LINK,
 	IFLA_VXLAN_LOCAL,
+	IFLA_VXLAN_REMOTE,
 	IFLA_VXLAN_TTL,
 	IFLA_VXLAN_TOS,
 	IFLA_VXLAN_LEARNING,
diff --git a/ip/iplink_vxlan.c b/ip/iplink_vxlan.c
index 1025326..ce2c30c 100644
--- a/ip/iplink_vxlan.c
+++ b/ip/iplink_vxlan.c
@@ -23,7 +23,8 @@
 
 static void explain(void)
 {
-	fprintf(stderr, "Usage: ... vxlan id VNI [ group ADDR ] [ local ADDR ]\n");
+	fprintf(stderr, "Usage: ... vxlan id VNI [ group ADDR ] [ remote ADDR ]\n");
+	fprintf(stderr, "                 [ local ADDR ]\n");
 	fprintf(stderr, "                 [ ttl TTL ] [ tos TOS ] [ dev PHYS_DEV ]\n");
 	fprintf(stderr, "                 [ port MIN MAX ] [ [no]learning ]\n");
 	fprintf(stderr, "                 [ [no]proxy ] [ [no]rsc ]\n");
@@ -41,6 +42,7 @@ static int vxlan_parse_opt(struct link_util *lu, int argc, char **argv,
 	__u32 vni = 0;
 	int vni_set = 0;
 	__u32 saddr = 0;
+	__u32 daddr = 0;
 	__u32 gaddr = 0;
 	unsigned link = 0;
 	__u8 tos = 0;
@@ -68,7 +70,13 @@ static int vxlan_parse_opt(struct link_util *lu, int argc, char **argv,
 			gaddr = get_addr32(*argv);
 
 			if (!IN_MULTICAST(ntohl(gaddr)))
-				invarg("invald group address", *argv);
+				invarg("invalid group address", *argv);
+		} else if (!matches(*argv, "remote")) {
+			NEXT_ARG();
+			daddr = get_addr32(*argv);
+
+			if (IN_MULTICAST(ntohl(daddr)))
+				invarg("invalid remote address", *argv);
 		} else if (!matches(*argv, "local")) {
 			NEXT_ARG();
 			if (strcmp(*argv, "any"))
@@ -160,9 +168,15 @@ static int vxlan_parse_opt(struct link_util *lu, int argc, char **argv,
 		fprintf(stderr, "vxlan: missing virtual network identifier\n");
 		return -1;
 	}
+	if (gaddr && daddr) {
+		fprintf(stderr, "vxlan: both group and remote cannot be specified\n");
+		return -1;
+	}
 	addattr32(n, 1024, IFLA_VXLAN_ID, vni);
 	if (gaddr)
 		addattr_l(n, 1024, IFLA_VXLAN_GROUP, &gaddr, 4);
+	else if (daddr)
+		addattr_l(n, 1024, IFLA_VXLAN_REMOTE, &daddr, 4);
 	if (saddr)
 		addattr_l(n, 1024, IFLA_VXLAN_LOCAL, &saddr, 4);
 	if (link)
@@ -213,6 +227,13 @@ static void vxlan_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[])
 				format_host(AF_INET, 4, &addr, s1, sizeof(s1)));
 	}
 
+	if (tb[IFLA_VXLAN_REMOTE]) {
+		__be32 addr = rta_getattr_u32(tb[IFLA_VXLAN_REMOTE]);
+		if (addr)
+			fprintf(f, "remote %s ",
+				format_host(AF_INET, 4, &addr, s1, sizeof(s1)));
+	}
+
 	if (tb[IFLA_VXLAN_LOCAL]) {
 		__be32 addr = rta_getattr_u32(tb[IFLA_VXLAN_LOCAL]);
 		if (addr)
-- 
1.8.1.5