From 68ea980e22e0b3178dfdf1cdeab3d71e3e71c1b9 Mon Sep 17 00:00:00 2001
From: melifaro <melifaro@FreeBSD.org>
Date: Sun, 29 Nov 2020 13:52:06 +0000
Subject: [PATCH] Add nhop_ref_any() to unify referencing nhop or nexthop
 group.

It allows code within routing subsystem to transparently reference nexthops
 and nexthop groups, similar to nhop_free_any(), abstracting ROUTE_MPATH
 details.

Differential Revision:	https://reviews.freebsd.org/D27410
---
 sys/net/route/nhgrp_ctl.c | 11 +++++++++++
 sys/net/route/nhop_ctl.c  | 13 +++++++++++++
 sys/net/route/route_var.h |  2 ++
 3 files changed, 26 insertions(+)

diff --git a/sys/net/route/nhgrp_ctl.c b/sys/net/route/nhgrp_ctl.c
index 2774f196625d..c4f86500ca8d 100644
--- a/sys/net/route/nhgrp_ctl.c
+++ b/sys/net/route/nhgrp_ctl.c
@@ -293,6 +293,17 @@ alloc_nhgrp(struct weightened_nhop *wn, int num_nhops)
 	return (nhg_priv);
 }
 
+void
+nhgrp_ref_object(struct nhgrp_object *nhg)
+{
+	struct nhgrp_priv *nhg_priv;
+	u_int old;
+
+	nhg_priv = NHGRP_PRIV(nhg);
+	old = refcount_acquire(&nhg_priv->nhg_refcount);
+	KASSERT(old > 0, ("%s: nhgrp object %p has 0 refs", __func__, nhg));
+}
+
 void
 nhgrp_free(struct nhgrp_object *nhg)
 {
diff --git a/sys/net/route/nhop_ctl.c b/sys/net/route/nhop_ctl.c
index 2b5bd740711b..2b676663a782 100644
--- a/sys/net/route/nhop_ctl.c
+++ b/sys/net/route/nhop_ctl.c
@@ -690,6 +690,19 @@ nhop_free(struct nhop_object *nh)
 	    &nh_priv->nh_epoch_ctx);
 }
 
+void
+nhop_ref_any(struct nhop_object *nh)
+{
+#ifdef ROUTE_MPATH
+	if (!NH_IS_NHGRP(nh))
+		nhop_ref_object(nh);
+	else
+		nhgrp_ref_object((struct nhgrp_object *)nh);
+#else
+	nhop_ref_object(nh);
+#endif
+}
+
 void
 nhop_free_any(struct nhop_object *nh)
 {
diff --git a/sys/net/route/route_var.h b/sys/net/route/route_var.h
index 58575531f87e..a24720cf2e71 100644
--- a/sys/net/route/route_var.h
+++ b/sys/net/route/route_var.h
@@ -242,6 +242,7 @@ int nhops_init_rib(struct rib_head *rh);
 void nhops_destroy_rib(struct rib_head *rh);
 void nhop_ref_object(struct nhop_object *nh);
 int nhop_try_ref_object(struct nhop_object *nh);
+void nhop_ref_any(struct nhop_object *nh);
 void nhop_free_any(struct nhop_object *nh);
 
 void nhop_set_type(struct nhop_object *nh, enum nhop_type nh_type);
@@ -306,6 +307,7 @@ int nhgrp_get_addition_group(struct rib_head *rnh,
     struct route_nhop_data *rnd_orig, struct route_nhop_data *rnd_add,
     struct route_nhop_data *rnd_new);
 
+void nhgrp_ref_object(struct nhgrp_object *nhg);
 uint32_t nhgrp_get_idx(const struct nhgrp_object *nhg);
 void nhgrp_free(struct nhgrp_object *nhg);