From 6576bd87387b1e5ee24aa8fbc82212dedd091138 Mon Sep 17 00:00:00 2001
From: David Lamparter <equinox@opensourcerouting.org>
Date: Thu, 2 Nov 2023 13:49:28 -0700
Subject: [PATCH] lib: convert if_zapi_callbacks into actual hooks

...so that multiple functions can be subscribed.

The create/destroy hooks are renamed to real/unreal because that's what
they *actually* signal.

Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
---
 babeld/babel_main.c      |  6 ++++--
 bfdd/ptm_adapter.c       |  3 ++-
 bgpd/bgp_zebra.c         |  6 ++++--
 eigrpd/eigrp_interface.c |  6 ++++--
 isisd/isis_circuit.c     |  6 ++++--
 ldpd/ldp_zebra.c         |  5 ++++-
 lib/if.c                 | 34 +++++++++-------------------------
 lib/if.h                 | 23 +++++++++++++++++++----
 nhrpd/nhrp_main.c        |  6 ++++--
 ospf6d/ospf6_interface.c |  6 ++++--
 ospfd/ospf_interface.c   |  6 ++++--
 pbrd/pbr_main.c          |  6 ++++--
 pimd/pim_iface.c         |  6 ++++--
 ripd/rip_interface.c     |  6 ++++--
 ripngd/ripng_interface.c |  6 ++++--
 sharpd/sharp_zebra.c     |  6 ++++--
 staticd/static_zebra.c   |  6 ++++--
 vrrpd/vrrp_zebra.c       |  6 ++++--
 zebra/interface.c        |  5 -----
 19 files changed, 90 insertions(+), 64 deletions(-)

diff --git a/babeld/babel_main.c b/babeld/babel_main.c
index b6126d5b7d19..4ca649e2c227 100644
--- a/babeld/babel_main.c
+++ b/babeld/babel_main.c
@@ -182,8 +182,10 @@ main(int argc, char **argv)
     change_smoothing_half_life(BABEL_DEFAULT_SMOOTHING_HALF_LIFE);
 
     /* init some quagga's dependencies, and babeld's commands */
-    if_zapi_callbacks(babel_ifp_create, babel_ifp_up,
-		      babel_ifp_down, babel_ifp_destroy);
+    hook_register_prio(if_real, 0, babel_ifp_create);
+    hook_register_prio(if_up, 0, babel_ifp_up);
+    hook_register_prio(if_down, 0, babel_ifp_down);
+    hook_register_prio(if_unreal, 0, babel_ifp_destroy);
     babeld_quagga_init();
     /* init zebra client's structure and it's commands */
     /* this replace kernel_setup && kernel_setup_socket */
diff --git a/bfdd/ptm_adapter.c b/bfdd/ptm_adapter.c
index 9e7ed114ee24..e6c2fb71f0cf 100644
--- a/bfdd/ptm_adapter.c
+++ b/bfdd/ptm_adapter.c
@@ -826,7 +826,8 @@ static zclient_handler *const bfd_handlers[] = {
 
 void bfdd_zclient_init(struct zebra_privs_t *bfdd_priv)
 {
-	if_zapi_callbacks(bfd_ifp_create, NULL, NULL, bfd_ifp_destroy);
+	hook_register_prio(if_real, 0, bfd_ifp_create);
+	hook_register_prio(if_unreal, 0, bfd_ifp_destroy);
 	zclient = zclient_new(master, &zclient_options_default, bfd_handlers,
 			      array_size(bfd_handlers));
 	assert(zclient != NULL);
diff --git a/bgpd/bgp_zebra.c b/bgpd/bgp_zebra.c
index ff8a87d76b3e..381acd803e04 100644
--- a/bgpd/bgp_zebra.c
+++ b/bgpd/bgp_zebra.c
@@ -3442,8 +3442,10 @@ void bgp_zebra_init(struct event_loop *master, unsigned short instance)
 	options.synchronous = true;
 	zclient_num_connects = 0;
 
-	if_zapi_callbacks(bgp_ifp_create, bgp_ifp_up,
-			  bgp_ifp_down, bgp_ifp_destroy);
+	hook_register_prio(if_real, 0, bgp_ifp_create);
+	hook_register_prio(if_up, 0, bgp_ifp_up);
+	hook_register_prio(if_down, 0, bgp_ifp_down);
+	hook_register_prio(if_unreal, 0, bgp_ifp_destroy);
 
 	/* Set default values. */
 	zclient = zclient_new(master, &zclient_options_default, bgp_handlers,
diff --git a/eigrpd/eigrp_interface.c b/eigrpd/eigrp_interface.c
index 7bb1617c1959..fb8f47e7234b 100644
--- a/eigrpd/eigrp_interface.c
+++ b/eigrpd/eigrp_interface.c
@@ -202,8 +202,10 @@ struct list *eigrp_iflist;
 
 void eigrp_if_init(void)
 {
-	if_zapi_callbacks(eigrp_ifp_create, eigrp_ifp_up,
-			  eigrp_ifp_down, eigrp_ifp_destroy);
+	hook_register_prio(if_real, 0, eigrp_ifp_create);
+	hook_register_prio(if_up, 0, eigrp_ifp_up);
+	hook_register_prio(if_down, 0, eigrp_ifp_down);
+	hook_register_prio(if_unreal, 0, eigrp_ifp_destroy);
 	/* Initialize Zebra interface data structure. */
 	// hook_register_prio(if_add, 0, eigrp_if_new);
 	hook_register_prio(if_del, 0, eigrp_if_delete_hook);
diff --git a/isisd/isis_circuit.c b/isisd/isis_circuit.c
index ffa6ad3e402d..3fca6b23d746 100644
--- a/isisd/isis_circuit.c
+++ b/isisd/isis_circuit.c
@@ -1680,6 +1680,8 @@ void isis_circuit_init(void)
 #else
 	if_cmd_init_default();
 #endif
-	if_zapi_callbacks(isis_ifp_create, isis_ifp_up,
-			  isis_ifp_down, isis_ifp_destroy);
+	hook_register_prio(if_real, 0, isis_ifp_create);
+	hook_register_prio(if_up, 0, isis_ifp_up);
+	hook_register_prio(if_down, 0, isis_ifp_down);
+	hook_register_prio(if_unreal, 0, isis_ifp_destroy);
 }
diff --git a/ldpd/ldp_zebra.c b/ldpd/ldp_zebra.c
index 0fd5d4613c08..a9814f18f8f0 100644
--- a/ldpd/ldp_zebra.c
+++ b/ldpd/ldp_zebra.c
@@ -682,7 +682,10 @@ static zclient_handler *const ldp_handlers[] = {
 
 void ldp_zebra_init(struct event_loop *master)
 {
-	if_zapi_callbacks(ldp_ifp_create, ldp_ifp_up, ldp_ifp_down, ldp_ifp_destroy);
+	hook_register_prio(if_real, 0, ldp_ifp_create);
+	hook_register_prio(if_up, 0, ldp_ifp_up);
+	hook_register_prio(if_down, 0, ldp_ifp_down);
+	hook_register_prio(if_unreal, 0, ldp_ifp_destroy);
 
 	/* Set default values. */
 	zclient = zclient_new(master, &zclient_options_default, ldp_handlers,
diff --git a/lib/if.c b/lib/if.c
index 48c01af882a4..775b03ef7d45 100644
--- a/lib/if.c
+++ b/lib/if.c
@@ -45,12 +45,11 @@ DEFINE_QOBJ_TYPE(interface);
 DEFINE_HOOK(if_add, (struct interface * ifp), (ifp));
 DEFINE_KOOH(if_del, (struct interface * ifp), (ifp));
 
-static struct interface_master{
-	int (*create_hook)(struct interface *ifp);
-	int (*up_hook)(struct interface *ifp);
-	int (*down_hook)(struct interface *ifp);
-	int (*destroy_hook)(struct interface *ifp);
-} ifp_master = { 0, };
+DEFINE_HOOK(if_real, (struct interface * ifp), (ifp));
+DEFINE_KOOH(if_unreal, (struct interface * ifp), (ifp));
+
+DEFINE_HOOK(if_up, (struct interface * ifp), (ifp));
+DEFINE_KOOH(if_down, (struct interface * ifp), (ifp));
 
 /* Compare interface names, returning an integer greater than, equal to, or
  * less than 0, (following the strcmp convention), according to the
@@ -180,14 +179,12 @@ static struct interface *if_new(struct vrf *vrf)
 
 void if_new_via_zapi(struct interface *ifp)
 {
-	if (ifp_master.create_hook)
-		(*ifp_master.create_hook)(ifp);
+	hook_call(if_real, ifp);
 }
 
 void if_destroy_via_zapi(struct interface *ifp)
 {
-	if (ifp_master.destroy_hook)
-		(*ifp_master.destroy_hook)(ifp);
+	hook_call(if_unreal, ifp);
 
 	ifp->oldifindex = ifp->ifindex;
 	if_set_index(ifp, IFINDEX_INTERNAL);
@@ -198,14 +195,12 @@ void if_destroy_via_zapi(struct interface *ifp)
 
 void if_up_via_zapi(struct interface *ifp)
 {
-	if (ifp_master.up_hook)
-		(*ifp_master.up_hook)(ifp);
+	hook_call(if_up, ifp);
 }
 
 void if_down_via_zapi(struct interface *ifp)
 {
-	if (ifp_master.down_hook)
-		(*ifp_master.down_hook)(ifp);
+	hook_call(if_down, ifp);
 }
 
 static struct interface *if_create_name(const char *name, struct vrf *vrf)
@@ -1477,17 +1472,6 @@ void if_cmd_init_default(void)
 	if_cmd_init(if_nb_config_write);
 }
 
-void if_zapi_callbacks(int (*create)(struct interface *ifp),
-		       int (*up)(struct interface *ifp),
-		       int (*down)(struct interface *ifp),
-		       int (*destroy)(struct interface *ifp))
-{
-	ifp_master.create_hook = create;
-	ifp_master.up_hook = up;
-	ifp_master.down_hook = down;
-	ifp_master.destroy_hook = destroy;
-}
-
 /* ------- Northbound callbacks ------- */
 
 /*
diff --git a/lib/if.h b/lib/if.h
index f93f0e70b87a..c24983a096c4 100644
--- a/lib/if.h
+++ b/lib/if.h
@@ -389,6 +389,25 @@ DECLARE_QOBJ_TYPE(interface);
 DECLARE_HOOK(if_add, (struct interface * ifp), (ifp));
 DECLARE_KOOH(if_del, (struct interface * ifp), (ifp));
 
+/* called (in daemons) when ZAPI tells us the interface actually exists
+ * (ifindex != IFINDEX_INTERNAL)
+ *
+ * WARNING: these 2 hooks NEVER CALLED inside zebra!
+ */
+DECLARE_HOOK(if_real, (struct interface * ifp), (ifp));
+DECLARE_KOOH(if_unreal, (struct interface * ifp), (ifp));
+
+/* called (in daemons) on state changes on interfaces.  Whether this is admin
+ * state (= pure config) or carrier state (= hardware link plugged) depends on
+ * zebra's "link-detect" configuration.  By default, it's carrier state, so
+ * this won't happen until the interface actually has a link.
+ *
+ * WARNING: these 2 hooks NEVER CALLED inside zebra!
+ */
+DECLARE_HOOK(if_up, (struct interface * ifp), (ifp));
+DECLARE_KOOH(if_down, (struct interface * ifp), (ifp));
+
+
 #define METRIC_MAX (~0)
 
 /* Connected address structure. */
@@ -609,10 +628,6 @@ extern void if_vty_config_start(struct vty *vty, struct interface *ifp);
 extern void if_vty_config_end(struct vty *vty);
 extern void if_cmd_init(int (*config_write)(struct vty *));
 extern void if_cmd_init_default(void);
-extern void if_zapi_callbacks(int (*create)(struct interface *ifp),
-			      int (*up)(struct interface *ifp),
-			      int (*down)(struct interface *ifp),
-			      int (*destroy)(struct interface *ifp));
 
 extern void if_new_via_zapi(struct interface *ifp);
 extern void if_up_via_zapi(struct interface *ifp);
diff --git a/nhrpd/nhrp_main.c b/nhrpd/nhrp_main.c
index e401f21ed485..73af78cbf0f8 100644
--- a/nhrpd/nhrp_main.c
+++ b/nhrpd/nhrp_main.c
@@ -155,8 +155,10 @@ int main(int argc, char **argv)
 	nhrp_vc_init();
 	nhrp_packet_init();
 	vici_init();
-	if_zapi_callbacks(nhrp_ifp_create, nhrp_ifp_up,
-			  nhrp_ifp_down, nhrp_ifp_destroy);
+	hook_register_prio(if_real, 0, nhrp_ifp_create);
+	hook_register_prio(if_up, 0, nhrp_ifp_up);
+	hook_register_prio(if_down, 0, nhrp_ifp_down);
+	hook_register_prio(if_unreal, 0, nhrp_ifp_destroy);
 	nhrp_zebra_init();
 	nhrp_shortcut_init();
 
diff --git a/ospf6d/ospf6_interface.c b/ospf6d/ospf6_interface.c
index 90185b09bcf1..a05ff1098cb3 100644
--- a/ospf6d/ospf6_interface.c
+++ b/ospf6d/ospf6_interface.c
@@ -2797,8 +2797,10 @@ void ospf6_interface_init(void)
 {
 	/* Install interface node. */
 	if_cmd_init(config_write_interface);
-	if_zapi_callbacks(ospf6_ifp_create, ospf6_ifp_up, ospf6_ifp_down,
-			  ospf6_ifp_destroy);
+	hook_register_prio(if_real, 0, ospf6_ifp_create);
+	hook_register_prio(if_up, 0, ospf6_ifp_up);
+	hook_register_prio(if_down, 0, ospf6_ifp_down);
+	hook_register_prio(if_unreal, 0, ospf6_ifp_destroy);
 
 	install_element(VIEW_NODE, &show_ipv6_ospf6_interface_prefix_cmd);
 	install_element(VIEW_NODE, &show_ipv6_ospf6_interface_ifname_cmd);
diff --git a/ospfd/ospf_interface.c b/ospfd/ospf_interface.c
index 938d373d8b1f..808eeb50fde2 100644
--- a/ospfd/ospf_interface.c
+++ b/ospfd/ospf_interface.c
@@ -1562,8 +1562,10 @@ void ospf_reset_hello_timer(struct interface *ifp, struct in_addr addr,
 
 void ospf_if_init(void)
 {
-	if_zapi_callbacks(ospf_ifp_create, ospf_ifp_up,
-			  ospf_ifp_down, ospf_ifp_destroy);
+	hook_register_prio(if_real, 0, ospf_ifp_create);
+	hook_register_prio(if_up, 0, ospf_ifp_up);
+	hook_register_prio(if_down, 0, ospf_ifp_down);
+	hook_register_prio(if_unreal, 0, ospf_ifp_destroy);
 
 	/* Initialize Zebra interface data structure. */
 	hook_register_prio(if_add, 0, ospf_if_new_hook);
diff --git a/pbrd/pbr_main.c b/pbrd/pbr_main.c
index c4708d3f08fe..6699079a688d 100644
--- a/pbrd/pbr_main.c
+++ b/pbrd/pbr_main.c
@@ -158,8 +158,10 @@ int main(int argc, char **argv, char **envp)
 	access_list_init();
 	pbr_nht_init();
 	pbr_map_init();
-	if_zapi_callbacks(pbr_ifp_create, pbr_ifp_up,
-			  pbr_ifp_down, pbr_ifp_destroy);
+	hook_register_prio(if_real, 0, pbr_ifp_create);
+	hook_register_prio(if_up, 0, pbr_ifp_up);
+	hook_register_prio(if_down, 0, pbr_ifp_down);
+	hook_register_prio(if_unreal, 0, pbr_ifp_destroy);
 	pbr_zebra_init();
 	pbr_vrf_init();
 	pbr_vty_init();
diff --git a/pimd/pim_iface.c b/pimd/pim_iface.c
index 5fa4715b052a..e00a3c0f9865 100644
--- a/pimd/pim_iface.c
+++ b/pimd/pim_iface.c
@@ -1771,8 +1771,10 @@ void pim_iface_init(void)
 	hook_register_prio(if_add, 0, pim_if_new_hook);
 	hook_register_prio(if_del, 0, pim_if_delete_hook);
 
-	if_zapi_callbacks(pim_ifp_create, pim_ifp_up, pim_ifp_down,
-			  pim_ifp_destroy);
+	hook_register_prio(if_real, 0, pim_ifp_create);
+	hook_register_prio(if_up, 0, pim_ifp_up);
+	hook_register_prio(if_down, 0, pim_ifp_down);
+	hook_register_prio(if_unreal, 0, pim_ifp_destroy);
 }
 
 static void pim_if_membership_clear(struct interface *ifp)
diff --git a/ripd/rip_interface.c b/ripd/rip_interface.c
index 505290ed3134..93494549ccfe 100644
--- a/ripd/rip_interface.c
+++ b/ripd/rip_interface.c
@@ -1118,6 +1118,8 @@ void rip_if_init(void)
 
 	/* Install interface node. */
 	if_cmd_init_default();
-	if_zapi_callbacks(rip_ifp_create, rip_ifp_up,
-			  rip_ifp_down, rip_ifp_destroy);
+	hook_register_prio(if_real, 0, rip_ifp_create);
+	hook_register_prio(if_up, 0, rip_ifp_up);
+	hook_register_prio(if_down, 0, rip_ifp_down);
+	hook_register_prio(if_unreal, 0, rip_ifp_destroy);
 }
diff --git a/ripngd/ripng_interface.c b/ripngd/ripng_interface.c
index 4cb4bb5ef38e..aa470aa65239 100644
--- a/ripngd/ripng_interface.c
+++ b/ripngd/ripng_interface.c
@@ -877,6 +877,8 @@ void ripng_if_init(void)
 
 	/* Install interface node. */
 	if_cmd_init_default();
-	if_zapi_callbacks(ripng_ifp_create, ripng_ifp_up,
-			  ripng_ifp_down, ripng_ifp_destroy);
+	hook_register_prio(if_real, 0, ripng_ifp_create);
+	hook_register_prio(if_up, 0, ripng_ifp_up);
+	hook_register_prio(if_down, 0, ripng_ifp_down);
+	hook_register_prio(if_unreal, 0, ripng_ifp_destroy);
 }
diff --git a/sharpd/sharp_zebra.c b/sharpd/sharp_zebra.c
index c095fec17b20..30bf4f30e195 100644
--- a/sharpd/sharp_zebra.c
+++ b/sharpd/sharp_zebra.c
@@ -1077,8 +1077,10 @@ void sharp_zebra_init(void)
 {
 	struct zclient_options opt = {.receive_notify = true};
 
-	if_zapi_callbacks(sharp_ifp_create, sharp_ifp_up, sharp_ifp_down,
-			  sharp_ifp_destroy);
+	hook_register_prio(if_real, 0, sharp_ifp_create);
+	hook_register_prio(if_up, 0, sharp_ifp_up);
+	hook_register_prio(if_down, 0, sharp_ifp_down);
+	hook_register_prio(if_unreal, 0, sharp_ifp_destroy);
 
 	zclient = zclient_new(master, &opt, sharp_handlers,
 			      array_size(sharp_handlers));
diff --git a/staticd/static_zebra.c b/staticd/static_zebra.c
index 6abbdadc085d..7799cbdee33c 100644
--- a/staticd/static_zebra.c
+++ b/staticd/static_zebra.c
@@ -542,8 +542,10 @@ void static_zebra_init(void)
 {
 	struct zclient_options opt = { .receive_notify = true };
 
-	if_zapi_callbacks(static_ifp_create, static_ifp_up,
-			  static_ifp_down, static_ifp_destroy);
+	hook_register_prio(if_real, 0, static_ifp_create);
+	hook_register_prio(if_up, 0, static_ifp_up);
+	hook_register_prio(if_down, 0, static_ifp_down);
+	hook_register_prio(if_unreal, 0, static_ifp_destroy);
 
 	zclient = zclient_new(master, &opt, static_handlers,
 			      array_size(static_handlers));
diff --git a/vrrpd/vrrp_zebra.c b/vrrpd/vrrp_zebra.c
index 6d753d2e4764..10394752e0b4 100644
--- a/vrrpd/vrrp_zebra.c
+++ b/vrrpd/vrrp_zebra.c
@@ -183,8 +183,10 @@ static zclient_handler *const vrrp_handlers[] = {
 
 void vrrp_zebra_init(void)
 {
-	if_zapi_callbacks(vrrp_ifp_create, vrrp_ifp_up,
-			  vrrp_ifp_down, vrrp_ifp_destroy);
+	hook_register_prio(if_real, 0, vrrp_ifp_create);
+	hook_register_prio(if_up, 0, vrrp_ifp_up);
+	hook_register_prio(if_down, 0, vrrp_ifp_down);
+	hook_register_prio(if_unreal, 0, vrrp_ifp_destroy);
 
 	/* Socket for receiving updates from Zebra daemon */
 	zclient = zclient_new(master, &zclient_options_default, vrrp_handlers,
diff --git a/zebra/interface.c b/zebra/interface.c
index 1afd9d5a7d8a..1283f15b05f8 100644
--- a/zebra/interface.c
+++ b/zebra/interface.c
@@ -5664,11 +5664,6 @@ void zebra_if_init(void)
 	/* Install configuration write function. */
 	if_cmd_init(if_config_write);
 	install_node(&link_params_node);
-	/*
-	 * This is *intentionally* setting this to NULL, signaling
-	 * that interface creation for zebra acts differently
-	 */
-	if_zapi_callbacks(NULL, NULL, NULL, NULL);
 
 	install_element(VIEW_NODE, &show_interface_cmd);
 	install_element(VIEW_NODE, &show_interface_vrf_all_cmd);