From: David Ahern <dsahern@kernel.org>
Date: Tue, 9 Jun 2020 17:27:28 -0600
Subject: vxlan: Remove access to nexthop group struct
Patch-mainline: v5.8-rc1
Git-commit: 50cb8769f2c1c657a470bda192b79ff679d0ecfc
References: bsc#1176447

vxlan driver should be using helpers to access nexthop struct
internals. Remove open check if whether nexthop is multipath in
favor of the existing nexthop_is_multipath helper. Add a new
helper, nexthop_has_v4, to cover the need to check has_v4 in
a group.

Fixes: 1274e1cc4226 ("vxlan: ecmp support for mac fdb entries")
Cc: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/vxlan.c   |    8 +++-----
 include/net/nexthop.h |   11 +++++++++++
 2 files changed, 14 insertions(+), 5 deletions(-)

--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -857,7 +857,6 @@ static int vxlan_fdb_nh_update(struct vx
 			       u32 nhid, struct netlink_ext_ack *extack)
 {
 	struct nexthop *old_nh = rtnl_dereference(fdb->nh);
-	struct nh_group *nhg;
 	struct nexthop *nh;
 	int err = -EINVAL;
 
@@ -881,8 +880,7 @@ static int vxlan_fdb_nh_update(struct vx
 			goto err_inval;
 		}
 
-		nhg = rtnl_dereference(nh->nh_grp);
-		if (!nh->is_group || !nhg->mpath) {
+		if (!nexthop_is_multipath(nh)) {
 			NL_SET_ERR_MSG(extack, "Nexthop is not a multipath group");
 			goto err_inval;
 		}
@@ -890,14 +888,14 @@ static int vxlan_fdb_nh_update(struct vx
 		/* check nexthop group family */
 		switch (vxlan->default_dst.remote_ip.sa.sa_family) {
 		case AF_INET:
-			if (!nhg->has_v4) {
+			if (!nexthop_has_v4(nh)) {
 				err = -EAFNOSUPPORT;
 				NL_SET_ERR_MSG(extack, "Nexthop group family not supported");
 				goto err_inval;
 			}
 			break;
 		case AF_INET6:
-			if (nhg->has_v4) {
+			if (nexthop_has_v4(nh)) {
 				err = -EAFNOSUPPORT;
 				NL_SET_ERR_MSG(extack, "Nexthop group family not supported");
 				goto err_inval;
--- a/include/net/nexthop.h
+++ b/include/net/nexthop.h
@@ -151,6 +151,17 @@ static inline bool nexthop_is_fdb(const
 	}
 }
 
+static inline bool nexthop_has_v4(const struct nexthop *nh)
+{
+	if (nh->is_group) {
+		struct nh_group *nh_grp;
+
+		nh_grp = rcu_dereference_rtnl(nh->nh_grp);
+		return nh_grp->has_v4;
+	}
+	return false;
+}
+
 static inline bool nexthop_is_multipath(const struct nexthop *nh)
 {
 	if (nh->is_group) {