Fix route flags update during RTM_CHANGE.

Nexthop lookup was not consireding rt_flags when doing
 structure comparison, which lead to an original nexthop
 selection when changing flags. Fix the case by adding
 rt_flags field into comparison and rearranging nhop_priv
 fields to allow for efficient matching.
Fix `route change X/Y flags` case - recent changes
 disallowed specifying RTF_GATEWAY flag without actual gateway.
 It turns out, route(8) fills in RTF_GATEWAY by default, unless
 -interface flag is specified. Fix regression by clearing
 RTF_GATEWAY flag instead of failing.
Fix route flag reporting in RTM_CHANGE messages by explicitly
 updating rtm_flags after operation competion.
Add IPv4/IPv6 tests for flag-only route changes.

4 files changed, 18 insertions, 6 deletions

diff --git a/sys/net/route/nhop_ctl.c b/sys/net/route/nhop_ctl.c
index 150ae5c4be58..fe30b0289ff1 100644
--- a/sys/net/route/nhop_ctl.c
+++ b/sys/net/route/nhop_ctl.c
@@ -164,8 +164,7 @@ cmp_priv(const struct nhop_priv *_one, const struct nhop_priv *_two)
 	if (memcmp(_one->nh, _two->nh, NHOP_END_CMP) != 0)
 		return (0);
 
-	if ((_one->nh_type != _two->nh_type) ||
-	    (_one->nh_family != _two->nh_family))
+	if (memcmp(_one, _two, NH_PRIV_END_CMP) != 0)
 		return (0);
 
 	return (1);
diff --git a/sys/net/route/nhop_var.h b/sys/net/route/nhop_var.h
index 6e1aba670e3c..4ce82dd4a968 100644
--- a/sys/net/route/nhop_var.h
+++ b/sys/net/route/nhop_var.h
@@ -74,13 +74,16 @@ struct nh_control {
 /* Control plane-only nhop data */
 struct nhop_object;
 struct nhop_priv {
-	uint32_t		nh_idx;		/* nexthop index */
+	/* nhop lookup comparison start */
 	uint8_t			nh_family;	/* address family of the lookup */
+	uint8_t			spare;
 	uint16_t		nh_type;	/* nexthop type */
+	uint32_t		rt_flags;	/* routing flags for the control plane */
+	/* nhop lookup comparison end */
+	uint32_t		nh_idx;		/* nexthop index */
 	void			*cb_func;	/* function handling additional rewrite caps */
 	u_int			nh_refcnt;	/* number of references, refcount(9)  */
 	u_int			nh_linked;	/* refcount(9), == 2 if linked to the list */
-	int			rt_flags;	/* routing flags for the control plane */
 	struct nhop_object	*nh;		/* backreference to the dataplane nhop */
 	struct nh_control	*nh_control;	/* backreference to the rnh */
 	struct nhop_priv	*nh_next;	/* hash table membership */
@@ -88,6 +91,8 @@ struct nhop_priv {
 	struct epoch_context	nh_epoch_ctx;	/* epoch data for nhop */
 };
 
+#define	NH_PRIV_END_CMP	(__offsetof(struct nhop_priv, nh_idx))
+
 #define	NH_IS_PINNED(_nh)	((!NH_IS_NHGRP(_nh)) && \
 				((_nh)->nh_priv->rt_flags & RTF_PINNED))
 
diff --git a/sys/net/route/route_ctl.c b/sys/net/route/route_ctl.c
index 6ee4931680f2..7a4d5003efb6 100644
--- a/sys/net/route/route_ctl.c
+++ b/sys/net/route/route_ctl.c
@@ -733,8 +733,15 @@ rib_change_route(uint32_t fibnum, struct rt_addrinfo *info,
 
 	/* Check if updated gateway exists */
 	if ((info->rti_flags & RTF_GATEWAY) &&
-	    (info->rti_info[RTAX_GATEWAY] == NULL))
-		return (EINVAL);
+	    (info->rti_info[RTAX_GATEWAY] == NULL)) {
+
+		/*
+		 * route(8) adds RTF_GATEWAY flag if -interface is not set.
+		 * Remove RTF_GATEWAY to enforce consistency and maintain
+		 * compatibility..
+		 */
+		info->rti_flags &= ~RTF_GATEWAY;
+	}
 
 	/*
 	 * route change is done in multiple steps, with dropping and
diff --git a/sys/net/rtsock.c b/sys/net/rtsock.c
index cdbe0d5b2118..83539de55b58 100644
--- a/sys/net/rtsock.c
+++ b/sys/net/rtsock.c
@@ -965,6 +965,7 @@ route_output(struct mbuf *m, struct socket *so, ...)
 #endif
 			nh = rc.rc_nh_new;
 			rtm->rtm_index = nh->nh_ifp->if_index;
+			rtm->rtm_flags = rc.rc_rt->rte_flags | nhop_get_rtflags(nh);
 		}
 		break;