bgpd: move l3nhg functions in separate bgp_nhg.[ch] file

This rework separates l3nhg functionality from the nexthop
tracking code, by introducing two bgp_nhg.[ch] files. The
calling functions are renamed from bgp_l3nhg* to bgp_nhg*.

Signed-off-by: Philippe Guibert <philippe.guibert@6wind.com>

8 files changed, 128 insertions, 101 deletions

diff --git a/bgpd/bgp_evpn_mh.c b/bgpd/bgp_evpn_mh.c
index a712310905..c7d8551b5e 100644
--- a/bgpd/bgp_evpn_mh.c
+++ b/bgpd/bgp_evpn_mh.c
@@ -37,7 +37,7 @@
 #include "bgpd/bgp_zebra.h"
 #include "bgpd/bgp_addpath.h"
 #include "bgpd/bgp_label.h"
-#include "bgpd/bgp_nht.h"
+#include "bgpd/bgp_nhg.h"
 #include "bgpd/bgp_mpath.h"
 #include "bgpd/bgp_trace.h"
 
@@ -3005,8 +3005,8 @@ static struct bgp_evpn_es_vrf *bgp_evpn_es_vrf_create(struct bgp_evpn_es *es,
 	listnode_add(es->es_vrf_list, &es_vrf->es_listnode);
 
 	/* setup the L3 NHG id for the ES */
-	es_vrf->nhg_id = bgp_l3nhg_id_alloc();
-	es_vrf->v6_nhg_id = bgp_l3nhg_id_alloc();
+	es_vrf->nhg_id = bgp_nhg_id_alloc();
+	es_vrf->v6_nhg_id = bgp_nhg_id_alloc();
 
 	if (BGP_DEBUG(evpn_mh, EVPN_MH_ES))
 		zlog_debug("es %s vrf %u nhg %u v6_nhg %d create", es->esi_str,
@@ -3034,10 +3034,10 @@ static void bgp_evpn_es_vrf_delete(struct bgp_evpn_es_vrf *es_vrf)
 	/* Remove the NHG resources */
 	bgp_evpn_l3nhg_deactivate(es_vrf);
 	if (es_vrf->nhg_id)
-		bgp_l3nhg_id_free(es_vrf->nhg_id);
+		bgp_nhg_id_free(es_vrf->nhg_id);
 	es_vrf->nhg_id = 0;
 	if (es_vrf->v6_nhg_id)
-		bgp_l3nhg_id_free(es_vrf->v6_nhg_id);
+		bgp_nhg_id_free(es_vrf->v6_nhg_id);
 	es_vrf->v6_nhg_id = 0;
 
 	/* remove from the ES's VRF list */
diff --git a/bgpd/bgp_main.c b/bgpd/bgp_main.c
index 11917c6c4a..e8d5a0307a 100644
--- a/bgpd/bgp_main.c
+++ b/bgpd/bgp_main.c
@@ -47,7 +47,7 @@
 #include "bgpd/bgp_errors.h"
 #include "bgpd/bgp_script.h"
 #include "bgpd/bgp_evpn_mh.h"
-#include "bgpd/bgp_nht.h"
+#include "bgpd/bgp_nhg.h"
 #include "bgpd/bgp_routemap_nb.h"
 #include "bgpd/bgp_community_alias.h"
 
@@ -199,7 +199,7 @@ static __attribute__((__noreturn__)) void bgp_exit(int status)
 		bgp_delete(bgp_default);
 
 	bgp_evpn_mh_finish();
-	bgp_l3nhg_finish();
+	bgp_nhg_finish();
 
 	/* reverse bgp_dump_init */
 	bgp_dump_finish();
diff --git a/bgpd/bgp_nhg.c b/bgpd/bgp_nhg.c
new file mode 100644
index 0000000000..bf0ba77444
--- /dev/null
+++ b/bgpd/bgp_nhg.c
@@ -0,0 +1,99 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* BGP Nexthop Group Support
+ * Copyright (C) 2023 NVIDIA Corporation
+ * Copyright (C) 2023 6WIND
+ */
+
+#include <zebra.h>
+
+#include <bgpd/bgpd.h>
+#include <bgpd/bgp_debug.h>
+#include <bgpd/bgp_nhg.h>
+
+
+/****************************************************************************
+ * L3 NHGs are used for fast failover of nexthops in the dplane. These are
+ * the APIs for allocating L3 NHG ids. Management of the L3 NHG itself is
+ * left to the application using it.
+ * PS: Currently EVPN host routes is the only app using L3 NHG for fast
+ * failover of remote ES links.
+ ***************************************************************************/
+static bitfield_t bgp_nh_id_bitmap;
+static uint32_t bgp_nhg_start;
+
+/* XXX - currently we do nothing on the callbacks */
+static void bgp_nhg_add_cb(const char *name)
+{
+}
+
+static void bgp_nhg_modify_cb(const struct nexthop_group_cmd *nhgc)
+{
+}
+
+static void bgp_nhg_add_nexthop_cb(const struct nexthop_group_cmd *nhgc,
+				   const struct nexthop *nhop)
+{
+}
+
+static void bgp_nhg_del_nexthop_cb(const struct nexthop_group_cmd *nhgc,
+				   const struct nexthop *nhop)
+{
+}
+
+static void bgp_nhg_del_cb(const char *name)
+{
+}
+
+static void bgp_nhg_zebra_init(void)
+{
+	static bool bgp_nhg_zebra_inited;
+
+	if (bgp_nhg_zebra_inited)
+		return;
+
+	bgp_nhg_zebra_inited = true;
+	bgp_nhg_start = zclient_get_nhg_start(ZEBRA_ROUTE_BGP);
+	nexthop_group_init(bgp_nhg_add_cb, bgp_nhg_modify_cb,
+			   bgp_nhg_add_nexthop_cb, bgp_nhg_del_nexthop_cb,
+			   bgp_nhg_del_cb);
+}
+
+void bgp_nhg_init(void)
+{
+	uint32_t id_max;
+
+	id_max = MIN(ZEBRA_NHG_PROTO_SPACING - 1, 16 * 1024);
+	bf_init(bgp_nh_id_bitmap, id_max);
+	bf_assign_zero_index(bgp_nh_id_bitmap);
+
+	if (BGP_DEBUG(nht, NHT) || BGP_DEBUG(evpn_mh, EVPN_MH_ES))
+		zlog_debug("bgp nhg range %u - %u", bgp_nhg_start + 1,
+			   bgp_nhg_start + id_max);
+}
+
+void bgp_nhg_finish(void)
+{
+	bf_free(bgp_nh_id_bitmap);
+}
+
+uint32_t bgp_nhg_id_alloc(void)
+{
+	uint32_t nhg_id = 0;
+
+	bgp_nhg_zebra_init();
+	bf_assign_index(bgp_nh_id_bitmap, nhg_id);
+	if (nhg_id)
+		nhg_id += bgp_nhg_start;
+
+	return nhg_id;
+}
+
+void bgp_nhg_id_free(uint32_t nhg_id)
+{
+	if (!nhg_id || (nhg_id <= bgp_nhg_start))
+		return;
+
+	nhg_id -= bgp_nhg_start;
+
+	bf_release_index(bgp_nh_id_bitmap, nhg_id);
+}
diff --git a/bgpd/bgp_nhg.h b/bgpd/bgp_nhg.h
new file mode 100644
index 0000000000..370e8ab091
--- /dev/null
+++ b/bgpd/bgp_nhg.h
@@ -0,0 +1,18 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* BGP Nexthop Group Support
+ * Copyright (C) 2023 NVIDIA Corporation
+ * Copyright (C) 2023 6WIND
+ */
+
+#ifndef _BGP_NHG_H
+#define _BGP_NHG_H
+
+#include "nexthop_group.h"
+
+/* APIs for setting up and allocating L3 nexthop group ids */
+extern uint32_t bgp_nhg_id_alloc(void);
+extern void bgp_nhg_id_free(uint32_t nhg_id);
+extern void bgp_nhg_init(void);
+void bgp_nhg_finish(void);
+
+#endif /* _BGP_NHG_H */
diff --git a/bgpd/bgp_nht.c b/bgpd/bgp_nht.c
index 10c0382f6f..05fd0dc4e7 100644
--- a/bgpd/bgp_nht.c
+++ b/bgpd/bgp_nht.c
@@ -1569,90 +1569,3 @@ void bgp_nht_dereg_enhe_cap_intfs(struct peer *peer)
 						0);
 	}
 }
-
-/****************************************************************************
- * L3 NHGs are used for fast failover of nexthops in the dplane. These are
- * the APIs for allocating L3 NHG ids. Management of the L3 NHG itself is
- * left to the application using it.
- * PS: Currently EVPN host routes is the only app using L3 NHG for fast
- * failover of remote ES links.
- ***************************************************************************/
-static bitfield_t bgp_nh_id_bitmap;
-static uint32_t bgp_l3nhg_start;
-
-/* XXX - currently we do nothing on the callbacks */
-static void bgp_l3nhg_add_cb(const char *name)
-{
-}
-
-static void bgp_l3nhg_modify_cb(const struct nexthop_group_cmd *nhgc)
-{
-}
-
-static void bgp_l3nhg_add_nexthop_cb(const struct nexthop_group_cmd *nhgc,
-				     const struct nexthop *nhop)
-{
-}
-
-static void bgp_l3nhg_del_nexthop_cb(const struct nexthop_group_cmd *nhgc,
-				     const struct nexthop *nhop)
-{
-}
-
-static void bgp_l3nhg_del_cb(const char *name)
-{
-}
-
-static void bgp_l3nhg_zebra_init(void)
-{
-	static bool bgp_l3nhg_zebra_inited;
-	if (bgp_l3nhg_zebra_inited)
-		return;
-
-	bgp_l3nhg_zebra_inited = true;
-	bgp_l3nhg_start = zclient_get_nhg_start(ZEBRA_ROUTE_BGP);
-	nexthop_group_init(bgp_l3nhg_add_cb, bgp_l3nhg_modify_cb,
-			   bgp_l3nhg_add_nexthop_cb, bgp_l3nhg_del_nexthop_cb,
-			   bgp_l3nhg_del_cb);
-}
-
-
-void bgp_l3nhg_init(void)
-{
-	uint32_t id_max;
-
-	id_max = MIN(ZEBRA_NHG_PROTO_SPACING - 1, 16 * 1024);
-	bf_init(bgp_nh_id_bitmap, id_max);
-	bf_assign_zero_index(bgp_nh_id_bitmap);
-
-	if (BGP_DEBUG(nht, NHT) || BGP_DEBUG(evpn_mh, EVPN_MH_ES))
-		zlog_debug("bgp l3_nhg range %u - %u", bgp_l3nhg_start + 1,
-			   bgp_l3nhg_start + id_max);
-}
-
-void bgp_l3nhg_finish(void)
-{
-	bf_free(bgp_nh_id_bitmap);
-}
-
-uint32_t bgp_l3nhg_id_alloc(void)
-{
-	uint32_t nhg_id = 0;
-
-	bgp_l3nhg_zebra_init();
-	bf_assign_index(bgp_nh_id_bitmap, nhg_id);
-	if (nhg_id)
-		nhg_id += bgp_l3nhg_start;
-
-	return nhg_id;
-}
-
-void bgp_l3nhg_id_free(uint32_t nhg_id)
-{
-	if (!nhg_id || (nhg_id <= bgp_l3nhg_start))
-		return;
-
-	nhg_id -= bgp_l3nhg_start;
-
-	bf_release_index(bgp_nh_id_bitmap, nhg_id);
-}
diff --git a/bgpd/bgp_nht.h b/bgpd/bgp_nht.h
index b9f0f6d469..e7c6fdc281 100644
--- a/bgpd/bgp_nht.h
+++ b/bgpd/bgp_nht.h
@@ -79,12 +79,6 @@ extern void bgp_nht_reg_enhe_cap_intfs(struct peer *peer);
 extern void bgp_nht_dereg_enhe_cap_intfs(struct peer *peer);
 extern void evaluate_paths(struct bgp_nexthop_cache *bnc);
 
-/* APIs for setting up and allocating L3 nexthop group ids */
-extern uint32_t bgp_l3nhg_id_alloc(void);
-extern void bgp_l3nhg_id_free(uint32_t nhg_id);
-extern void bgp_l3nhg_init(void);
-void bgp_l3nhg_finish(void);
-
 extern void bgp_nht_ifp_up(struct interface *ifp);
 extern void bgp_nht_ifp_down(struct interface *ifp);
 
diff --git a/bgpd/bgpd.c b/bgpd/bgpd.c
index 4fa021ab93..0023855a9f 100644
--- a/bgpd/bgpd.c
+++ b/bgpd/bgpd.c
@@ -63,6 +63,7 @@
 #include "bgpd/bgp_vty.h"
 #include "bgpd/bgp_mpath.h"
 #include "bgpd/bgp_nht.h"
+#include "bgpd/bgp_nhg.h"
 #include "bgpd/bgp_updgrp.h"
 #include "bgpd/bgp_bfd.h"
 #include "bgpd/bgp_memory.h"
@@ -8264,7 +8265,7 @@ void bgp_master_init(struct event_loop *master, const int buffer_size,
 	/* mpls label dynamic allocation pool */
 	bgp_lp_init(bm->master, &bm->labelpool);
 
-	bgp_l3nhg_init();
+	bgp_nhg_init();
 	bgp_evpn_mh_init();
 	QOBJ_REG(bm, bgp_master);
 }
diff --git a/bgpd/subdir.am b/bgpd/subdir.am
index 7de6e7a9f1..6d6fad0074 100644
--- a/bgpd/subdir.am
+++ b/bgpd/subdir.am
@@ -77,6 +77,7 @@ bgpd_libbgp_a_SOURCES = \
 	bgpd/bgp_zebra.c \
 	bgpd/bgpd.c \
 	bgpd/bgp_trace.c \
+	bgpd/bgp_nhg.c \
 	# end
 
 if ENABLE_BGP_VNC
@@ -160,6 +161,7 @@ noinst_HEADERS += \
 	bgpd/bgp_zebra.h \
 	bgpd/bgpd.h \
 	bgpd/bgp_trace.h \
+	bgpd/bgp_nhg.h \
 	\
 	bgpd/rfapi/bgp_rfapi_cfg.h \
 	bgpd/rfapi/rfapi_import.h \