routing: add abitity to set the protocol that installed route/nexthop.

Routing daemons such as bird need to know if they install certain route
 so they can clean it up on startup, as a form of achieving consistent
 state during the crash recovery.
Currently they use combination of routing flags (RTF_PROTO1) to detect
 these routes when interacting via route(4) rtsock protocol.
Netlink protocol has a special "rtm_protocol" field that is filled and
 checked by the route originator. To prepare for the upcoming netlink
 introduction, add ability to record origing to both nexthops and
 nexthop groups via <nhop|nhgrp>_<get|set>_origin() KPI. The actual
 calls will be used in the followup commits.

MFC after:	1 month

sys/net/route.c

@@ -217,6 +217,7 @@ rib_add_redirect(u_int fibnum, struct sockaddr *dst, struct sockaddr *gateway,
 	nhop_set_pxtype_flag(nh, NHF_HOST);
 	nhop_set_expire(nh, lifetime_sec + time_uptime);
 	nhop_set_redirect(nh, true);
+	nhop_set_origin(nh, NH_ORIGIN_REDIRECT);
 	rnd.rnd_nhop = nhop_get_nhop(nh, &error);
 	if (error == 0) {
 		error = rib_add_route_px(fibnum, dst, -1,

sys/net/route/nhgrp_ctl.c

@@ -852,6 +852,18 @@ nhgrp_get_idx(const struct nhgrp_object *nhg)
 	return (nhg_priv->nhg_idx);
 }
 
+uint8_t
+nhgrp_get_origin(struct nhgrp_object *nhg)
+{
+	return (NHGRP_PRIV(nhg)->nhg_origin);
+}
+
+void
+nhgrp_set_origin(struct nhgrp_object *nhg, uint8_t origin)
+{
+	NHGRP_PRIV(nhg)->nhg_origin = origin;
+}
+
 uint32_t
 nhgrp_get_count(struct rib_head *rh)
 {

sys/net/route/nhgrp_var.h

@@ -49,7 +49,8 @@ struct nhgrp_priv {
 	uint32_t		nhg_idx;
 	uint32_t		nhg_uidx;
 	uint8_t			nhg_nh_count;	/* number of items in nh_weights */
-	uint8_t			nhg_spare[3];
+	uint8_t			nhg_origin;	/* protocol which created the group */
+	uint8_t			nhg_spare[2];
 	u_int			nhg_refcount;	/* use refcount */
 	u_int			nhg_linked;	/* refcount(9), == 2 if linked to the list */
 	struct nh_control	*nh_control;	/* parent control structure */

sys/net/route/nhop.h

@@ -199,6 +199,14 @@ void nhop_set_type(struct nhop_object *nh, enum nhop_type nh_type);
 void nhop_set_src(struct nhop_object *nh, struct ifaddr *ifa);
 void nhop_set_transmit_ifp(struct nhop_object *nh, struct ifnet *ifp);
 
+#define	NH_ORIGIN_UNSPEC	0 /* not set */
+#define	NH_ORIGIN_REDIRECT	1 /* kernel-originated redirect */
+#define	NH_ORIGIN_KERNEL	2 /* kernel (interface) routes */
+#define	NH_ORIGIN_BOOT		3 /* kernel-originated routes at boot */
+#define	NH_ORIGIN_STATIC	4 /* route(8) routes */
+void nhop_set_origin(struct nhop_object *nh, uint8_t origin);
+uint8_t nhop_get_origin(struct nhop_object *nh);
+
 uint32_t nhop_get_idx(const struct nhop_object *nh);
 uint32_t nhop_get_uidx(const struct nhop_object *nh);
 void nhop_set_uidx(struct nhop_object *nh, uint32_t uidx);
@@ -217,6 +225,8 @@ struct rib_head *nhop_get_rh(const struct nhop_object *nh);
 
 struct nhgrp_object;
 uint32_t nhgrp_get_uidx(const struct nhgrp_object *nhg);
+uint8_t nhgrp_get_origin(struct nhgrp_object *nhg);
+void nhgrp_set_origin(struct nhgrp_object *nhg, uint8_t origin);
 #endif /* _KERNEL */
 
 /* Kernel <> userland structures */

sys/net/route/nhop_ctl.c

@@ -1012,6 +1012,18 @@ nhop_get_rh(const struct nhop_object *nh)
 	return (rt_tables_get_rnh(fibnum, family));
 }
 
+uint8_t
+nhop_get_origin(struct nhop_object *nh)
+{
+	return (nh->nh_priv->nh_origin);
+}
+
+void
+nhop_set_origin(struct nhop_object *nh, uint8_t origin)
+{
+	nh->nh_priv->nh_origin = origin;
+}
+
 void
 nhops_update_ifmtu(struct rib_head *rh, struct ifnet *ifp, uint32_t mtu)
 {

sys/net/route/nhop_var.h

@@ -87,6 +87,7 @@ struct nhop_priv {
 	u_int			nh_refcnt;	/* number of references, refcount(9)  */
 	u_int			nh_linked;	/* refcount(9), == 2 if linked to the list */
 	int			nh_finalized;	/* non-zero if finalized() was called */
+	uint8_t			nh_origin;	/* protocol that originated the nexthop */
 	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 */

sys/net/route/route_ctl.c

@@ -622,6 +622,7 @@ rib_copy_route(struct rtentry *rt, const struct route_nhop_data *rnd_src,
 		return (ENOMEM);
 	}
 	nhop_copy(nh, rnd_src->rnd_nhop);
+	nhop_set_origin(nh, nhop_get_origin(rnd_src->rnd_nhop));
 	nhop_set_fibnum(nh, rh_dst->rib_fibnum);
 	nh = nhop_get_nhop_internal(rh_dst, nh, &error);
 	if (error != 0) {