From 2d9ae462ea455a8bd88fe96b31bf51197ecacf71 Mon Sep 17 00:00:00 2001
From: Matthew Smith <mgsmith@netgate.com>
Date: Tue, 22 Jun 2021 09:36:50 -0500
Subject: [PATCH] linux-cp: add callbacks for pair management

Type: improvement

Allow callbacks to be registered which will be called when an
interface pair is added or deleted.

Change-Id: I1c413ac2ada802021f9e56e2f878ce67e5eda2f5
Signed-off-by: Matthew Smith <mgsmith@netgate.com>
---
 src/plugins/linux-cp/lcp_interface.c | 46 ++++++++++++++++++++++++------------
 src/plugins/linux-cp/lcp_interface.h | 10 ++++++++
 2 files changed, 41 insertions(+), 15 deletions(-)

diff --git a/src/plugins/linux-cp/lcp_interface.c b/src/plugins/linux-cp/lcp_interface.c
index e33c34b5f6a..5c4cd494232 100644
--- a/src/plugins/linux-cp/lcp_interface.c
+++ b/src/plugins/linux-cp/lcp_interface.c
@@ -60,6 +60,17 @@ static uword *lip_db_by_vif;
 index_t *lip_db_by_phy;
 u32 *lip_db_by_host;
 
+/**
+ * vector of virtual function table
+ */
+static lcp_itf_pair_vft_t *lcp_itf_vfts = NULL;
+
+void
+lcp_itf_pair_register_vft (lcp_itf_pair_vft_t *lcp_itf_vft)
+{
+  vec_add1 (lcp_itf_vfts, *lcp_itf_vft);
+}
+
 #define LCP_ITF_PAIR_DBG(...)                                                 \
   vlib_log_notice (lcp_itf_pair_logger, __VA_ARGS__);
 
@@ -216,12 +227,6 @@ lcp_itf_set_adjs (lcp_itf_pair_t *lip)
   lip->lip_rewrite_len = adj->rewrite_header.data_bytes;
 }
 
-int __clib_weak
-lcp_nl_drain_messages (void)
-{
-  return 0;
-}
-
 int
 lcp_itf_pair_add (u32 host_sw_if_index, u32 phy_sw_if_index, u8 *host_name,
 		  u32 host_index, lip_host_type_t host_type, u8 *ns)
@@ -240,14 +245,6 @@ lcp_itf_pair_add (u32 host_sw_if_index, u32 phy_sw_if_index, u8 *host_name,
   if (lipi != INDEX_INVALID)
     return VNET_API_ERROR_VALUE_EXIST;
 
-  /*
-   * Drain netlink messages before adding the new pair.
-   * This avoids unnecessarily applying messages that were generated by
-   * the creation of the tap/tun interface. By processing them before we
-   * store the pair data, we will ensure that they are ignored.
-   */
-  lcp_nl_drain_messages ();
-
   /*
    * Create a new pair.
    */
@@ -267,7 +264,6 @@ lcp_itf_pair_add (u32 host_sw_if_index, u32 phy_sw_if_index, u8 *host_name,
   lip->lip_host_type = host_type;
   lip->lip_vif_index = host_index;
   lip->lip_namespace = vec_dup (ns);
-  lip->lip_create_ts = vlib_time_now (vlib_get_main ());
 
   if (lip->lip_host_sw_if_index == ~0)
     return 0;
@@ -323,6 +319,18 @@ lcp_itf_pair_add (u32 host_sw_if_index, u32 phy_sw_if_index, u8 *host_name,
 				   0);
     }
 
+  /* invoke registered callbacks for pair addition */
+  lcp_itf_pair_vft_t *vft;
+
+  vec_foreach (vft, lcp_itf_vfts)
+    {
+      if (vft->pair_add_fn)
+	vft->pair_add_fn (lip);
+    }
+
+  /* set timestamp when pair entered service */
+  lip->lip_create_ts = vlib_time_now (vlib_get_main ());
+
   return 0;
 }
 
@@ -382,6 +390,7 @@ lcp_itf_pair_del (u32 phy_sw_if_index)
   ip_address_family_t af;
   lcp_itf_pair_t *lip;
   u32 lipi;
+  lcp_itf_pair_vft_t *vft;
 
   lipi = lcp_itf_pair_find_by_phy (phy_sw_if_index);
 
@@ -395,6 +404,13 @@ lcp_itf_pair_del (u32 phy_sw_if_index)
 		     format_vnet_sw_if_index_name, vnet_get_main (),
 		     lip->lip_host_sw_if_index, lip->lip_host_name);
 
+  /* invoke registered callbacks for pair deletion */
+  vec_foreach (vft, lcp_itf_vfts)
+    {
+      if (vft->pair_del_fn)
+	vft->pair_del_fn (lip);
+    }
+
   FOR_EACH_IP_ADDRESS_FAMILY (af)
   ip_feature_enable_disable (af, N_SAFI, IP_FEATURE_INPUT,
 			     lcp_itf_l3_feat_names[lip->lip_host_type][af],
diff --git a/src/plugins/linux-cp/lcp_interface.h b/src/plugins/linux-cp/lcp_interface.h
index be566a07cb6..bed30248845 100644
--- a/src/plugins/linux-cp/lcp_interface.h
+++ b/src/plugins/linux-cp/lcp_interface.h
@@ -150,6 +150,16 @@ lcp_itf_pair_find_by_host (u32 host_sw_if_index)
 void lcp_set_auto_intf (u8 is_auto);
 int lcp_auto_intf (void);
 
+typedef void (*lcp_itf_pair_add_cb_t) (lcp_itf_pair_t *);
+typedef void (*lcp_itf_pair_del_cb_t) (lcp_itf_pair_t *);
+
+typedef struct lcp_itf_pair_vft
+{
+  lcp_itf_pair_add_cb_t pair_add_fn;
+  lcp_itf_pair_del_cb_t pair_del_fn;
+} lcp_itf_pair_vft_t;
+
+void lcp_itf_pair_register_vft (lcp_itf_pair_vft_t *lcp_itf_vft);
 /*
  * fd.io coding-style-patch-verification: ON
  *
-- 
2.16.6