wireguard: add events for peer

we can receive events from peer about its state:
-WIREGUARD_PEER_STATUS_DEAD
-WIREGUARD_PEER_ESTABLISHED

Type: improvement
Change-Id: Ide83fbe2cfafa79ded5bcf3f6a884c26a7583db0
Signed-off-by: Artem Glazychev <artem.glazychev@xored.com>

8 files changed, 223 insertions, 33 deletions

diff --git a/src/plugins/wireguard/wireguard.api b/src/plugins/wireguard/wireguard.api
index e290fc41ffc..1473d9ca39b 100755
--- a/src/plugins/wireguard/wireguard.api
+++ b/src/plugins/wireguard/wireguard.api
@@ -83,6 +83,7 @@ define wireguard_interface_details
 enum wireguard_peer_flags : u8
 {
   WIREGUARD_PEER_STATUS_DEAD = 0x1,
+  WIREGUARD_PEER_ESTABLISHED = 0x2,
 };
 
 /** \brief Create new peer
@@ -107,6 +108,41 @@ typedef wireguard_peer
   vl_api_prefix_t allowed_ips[n_allowed_ips];
 };
 
+service {
+  rpc want_wireguard_peer_events returns want_wireguard_peer_events_reply
+    events wireguard_peer_event;
+};
+/** \brief Register for wireguard peer events
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+    @param sw_if_index - index of the interface to dump peer info on, ~0 if on all
+    @param peer_index - index of the peer to dump info on, ~0 if on all
+    @param enable_disable - 1 => register for events, 0 => cancel registration
+    @param pid - sender's pid
+*/
+autoreply define want_wireguard_peer_events
+{
+  u32 client_index;
+  u32 context;
+  vl_api_interface_index_t sw_if_index [default=0xFFFFFFFF];
+  u32 peer_index [default=0xFFFFFFFF];
+  u32 enable_disable;
+  u32 pid;
+};
+/** \brief Interface Event generated by want_wireguard_peer_events
+    @param client_index - opaque cookie to identify the sender
+    @param pid - client pid registered to receive notification
+    @param peer_index - index of the peer for this event
+    @param deleted - interface was deleted
+*/
+define wireguard_peer_event
+{
+  u32 client_index;
+  u32 pid;
+  u32 peer_index;
+  vl_api_wireguard_peer_flags_t flags;
+};
+
 /** \brief Create new peer
     @param client_index - opaque cookie to identify the sender
     @param context - sender context, to match reply w/ request
@@ -140,10 +176,12 @@ autoreply define wireguard_peer_remove
 /** \brief Dump all peers
     @param client_index - opaque cookie to identify the sender
     @param context - sender context, to match reply w/ request
+    @param peer_index - peer index to be dumped.  If 0xFFFFFFFF dumps all peers
 */
 define wireguard_peers_dump {
   u32 client_index;
   u32 context;
+  u32 peer_index [default=0xFFFFFFFF];
 };
 
 /** \brief Dump peers response
diff --git a/src/plugins/wireguard/wireguard_api.c b/src/plugins/wireguard/wireguard_api.c
index 5dd4f86f910..d97ea8eb1bc 100644
--- a/src/plugins/wireguard/wireguard_api.c
+++ b/src/plugins/wireguard/wireguard_api.c
@@ -27,9 +27,9 @@
 #include <wireguard/wireguard_key.h>
 #include <wireguard/wireguard.h>
 #include <wireguard/wireguard_if.h>
-#include <wireguard/wireguard_peer.h>
 
 #define REPLY_MSG_ID_BASE wmp->msg_id_base
+#include <wireguard/wireguard_peer.h>
 #include <vlibapi/api_helper_macros.h>
 
 static void
@@ -55,12 +55,10 @@ static void
   rv = wg_if_create (ntohl (mp->interface.user_instance), private_key,
 		     ntohs (mp->interface.port), &src, &sw_if_index);
 
-  /* *INDENT-OFF* */
   REPLY_MACRO2(VL_API_WIREGUARD_INTERFACE_CREATE_REPLY,
   {
     rmp->sw_if_index = htonl(sw_if_index);
   });
-  /* *INDENT-ON* */
 }
 
 static void
@@ -79,9 +77,7 @@ static void
 
   BAD_SW_IF_INDEX_LABEL;
 
-  /* *INDENT-OFF* */
   REPLY_MACRO(VL_API_WIREGUARD_INTERFACE_DELETE_REPLY);
-  /* *INDENT-ON* */
 }
 
 typedef struct wg_deatils_walk_t_
@@ -179,12 +175,11 @@ vl_api_wireguard_peer_add_t_handler (vl_api_wireguard_peer_add_t * mp)
   vec_free (allowed_ips);
 done:
   BAD_SW_IF_INDEX_LABEL;
-  /* *INDENT-OFF* */
+
   REPLY_MACRO2(VL_API_WIREGUARD_PEER_ADD_REPLY,
   {
     rmp->peer_index = ntohl (peeri);
   });
-  /* *INDENT-ON* */
 }
 
 static void
@@ -198,13 +193,11 @@ vl_api_wireguard_peer_remove_t_handler (vl_api_wireguard_peer_remove_t * mp)
 
   rv = wg_peer_remove (ntohl (mp->peer_index));
 
-  /* *INDENT-OFF* */
   REPLY_MACRO(VL_API_WIREGUARD_PEER_REMOVE_REPLY);
-  /* *INDENT-ON* */
 }
 
 static walk_rc_t
-send_wg_peers_details (index_t peeri, void *data)
+wg_api_send_peers_details (index_t peeri, void *data)
 {
   vl_api_wireguard_peers_details_t *rmp;
   wg_deatils_walk_t *ctx = data;
@@ -212,7 +205,11 @@ send_wg_peers_details (index_t peeri, void *data)
   u8 n_allowed_ips;
   size_t ss;
 
+  if (pool_is_free_index (wg_peer_pool, peeri))
+    return (WALK_CONTINUE);
+
   peer = wg_peer_get (peeri);
+
   n_allowed_ips = vec_len (peer->allowed_ips);
 
   ss = (sizeof (*rmp) + (n_allowed_ips * sizeof (rmp->peer.allowed_ips[0])));
@@ -222,8 +219,7 @@ send_wg_peers_details (index_t peeri, void *data)
   rmp->_vl_msg_id = htons (VL_API_WIREGUARD_PEERS_DETAILS +
 			   wg_main.msg_id_base);
 
-  if (peer->is_dead)
-    rmp->peer.flags = WIREGUARD_PEER_STATUS_DEAD;
+  rmp->peer.flags = peer->flags;
   clib_memcpy (rmp->peer.public_key,
 	       peer->remote.r_public, NOISE_PUBLIC_KEY_LEN);
 
@@ -260,7 +256,113 @@ vl_api_wireguard_peers_dump_t_handler (vl_api_wireguard_peers_dump_t * mp)
     .context = mp->context,
   };
 
-  wg_peer_walk (send_wg_peers_details, &ctx);
+  if (mp->peer_index == ~0)
+    wg_peer_walk (wg_api_send_peers_details, &ctx);
+  else
+    wg_api_send_peers_details (mp->peer_index, &ctx);
+}
+
+static vpe_client_registration_t *
+wg_api_client_lookup (wg_peer_t *peer, u32 client_index)
+{
+  uword *p;
+  vpe_client_registration_t *api_client = NULL;
+
+  p = hash_get (peer->api_client_by_client_index, client_index);
+  if (p)
+    api_client = vec_elt_at_index (peer->api_clients, p[0]);
+
+  return api_client;
+}
+
+static walk_rc_t
+wg_api_update_peer_api_client (index_t peeri, void *data)
+{
+  if (pool_is_free_index (wg_peer_pool, peeri))
+    return (WALK_CONTINUE);
+
+  vl_api_want_wireguard_peer_events_t *mp = data;
+  wg_peer_t *peer = wg_peer_get (peeri);
+
+  if (ntohl (mp->sw_if_index) != ~0 &&
+      ntohl (mp->sw_if_index) != peer->wg_sw_if_index)
+    {
+      return (WALK_CONTINUE);
+    }
+
+  vpe_client_registration_t *api_client;
+
+  api_client = wg_api_client_lookup (peer, mp->client_index);
+
+  if (api_client)
+    {
+      if (mp->enable_disable)
+	{
+	  return (WALK_CONTINUE);
+	}
+      hash_unset (peer->api_client_by_client_index, api_client->client_index);
+      pool_put (peer->api_clients, api_client);
+    }
+  if (mp->enable_disable)
+    {
+      pool_get (peer->api_clients, api_client);
+      clib_memset (api_client, 0, sizeof (vpe_client_registration_t));
+      api_client->client_index = mp->client_index;
+      api_client->client_pid = mp->pid;
+      hash_set (peer->api_client_by_client_index, mp->client_index,
+		api_client - peer->api_clients);
+    }
+
+  return (WALK_CONTINUE);
+}
+
+static void
+vl_api_want_wireguard_peer_events_t_handler (
+  vl_api_want_wireguard_peer_events_t *mp)
+{
+  wg_main_t *wmp = &wg_main;
+  vl_api_want_wireguard_peer_events_reply_t *rmp;
+  int rv = 0;
+
+  wg_feature_init (wmp);
+
+  if (mp->peer_index == ~0)
+    wg_peer_walk (wg_api_update_peer_api_client, mp);
+  else
+    wg_api_update_peer_api_client (ntohl (mp->peer_index), mp);
+
+  REPLY_MACRO (VL_API_WANT_WIREGUARD_PEER_EVENTS_REPLY);
+}
+
+void
+wg_api_send_peer_event (vl_api_registration_t *rp, index_t peer_index,
+			wg_peer_flags flags)
+{
+  vl_api_wireguard_peer_event_t *mp = vl_msg_api_alloc (sizeof (*mp));
+  clib_memset (mp, 0, sizeof (*mp));
+
+  mp->_vl_msg_id = htons (VL_API_WIREGUARD_PEER_EVENT + wg_main.msg_id_base);
+  mp->peer_index = htonl (peer_index);
+  mp->flags = flags;
+
+  vl_api_send_msg (rp, (u8 *) mp);
+}
+
+void
+wg_api_peer_event (index_t peeri, wg_peer_flags flags)
+{
+  wg_peer_t *peer = wg_peer_get (peeri);
+  vpe_client_registration_t *api_client;
+  vl_api_registration_t *rp;
+
+  pool_foreach (api_client, peer->api_clients)
+    {
+      rp = vl_api_client_index_to_registration (api_client->client_index);
+      if (rp)
+	{
+	  wg_api_send_peer_event (rp, peeri, flags);
+	}
+    };
 }
 
 /* set tup the API message handling tables */
diff --git a/src/plugins/wireguard/wireguard_input.c b/src/plugins/wireguard/wireguard_input.c
index 6a0623e0a76..4f5bd4de784 100644
--- a/src/plugins/wireguard/wireguard_input.c
+++ b/src/plugins/wireguard/wireguard_input.c
@@ -236,6 +236,10 @@ wg_handshake_process (vlib_main_t *vm, wg_main_t *wmp, vlib_buffer_t *b,
 	    vlib_node_increment_counter (vm, node_idx,
 					 WG_INPUT_ERROR_HANDSHAKE_SEND, 1);
 	  }
+	else
+	  {
+	    wg_peer_update_flags (rp->r_peer_idx, WG_PEER_ESTABLISHED, true);
+	  }
 	break;
       }
     case MESSAGE_HANDSHAKE_RESPONSE:
@@ -247,7 +251,7 @@ wg_handshake_process (vlib_main_t *vm, wg_main_t *wmp, vlib_buffer_t *b,
 	if (PREDICT_TRUE (entry != NULL))
 	  {
 	    peer = wg_peer_get (*entry);
-	    if (peer->is_dead)
+	    if (wg_peer_is_dead (peer))
 	      return WG_INPUT_ERROR_PEER;
 	  }
 	else
@@ -276,6 +280,10 @@ wg_handshake_process (vlib_main_t *vm, wg_main_t *wmp, vlib_buffer_t *b,
 		vlib_node_increment_counter (vm, node_idx,
 					     WG_INPUT_ERROR_KEEPALIVE_SEND, 1);
 	      }
+	    else
+	      {
+		wg_peer_update_flags (*entry, WG_PEER_ESTABLISHED, true);
+	      }
 	  }
 	break;
       }
@@ -378,6 +386,7 @@ wg_input_inline (vlib_main_t *vm, vlib_node_runtime_t *node,
 	    }
 	  else if (PREDICT_FALSE (state_cr == SC_FAILED))
 	    {
+	      wg_peer_update_flags (*peer_idx, WG_PEER_ESTABLISHED, false);
 	      next[0] = WG_INPUT_NEXT_ERROR;
 	      b[0]->error = node->errors[WG_INPUT_ERROR_DECRYPTION];
 	      goto out;
diff --git a/src/plugins/wireguard/wireguard_output_tun.c b/src/plugins/wireguard/wireguard_output_tun.c
index 80ba9504f0e..ec6cb7c6cfb 100644
--- a/src/plugins/wireguard/wireguard_output_tun.c
+++ b/src/plugins/wireguard/wireguard_output_tun.c
@@ -129,7 +129,7 @@ wg_output_tun_inline (vlib_main_t *vm, vlib_node_runtime_t *node,
 	wg_peer_get_by_adj_index (vnet_buffer (b[0])->ip.adj_index[VLIB_TX]);
       peer = wg_peer_get (peeri);
 
-      if (!peer || peer->is_dead)
+      if (wg_peer_is_dead (peer))
 	{
 	  b[0]->error = node->errors[WG_OUTPUT_ERROR_PEER];
 	  goto out;
@@ -201,6 +201,7 @@ wg_output_tun_inline (vlib_main_t *vm, vlib_node_runtime_t *node,
 	{
 	  //TODO: Maybe wrong
 	  wg_send_handshake_from_mt (peeri, false);
+	  wg_peer_update_flags (peeri, WG_PEER_ESTABLISHED, false);
 	  goto out;
 	}
 
diff --git a/src/plugins/wireguard/wireguard_peer.c b/src/plugins/wireguard/wireguard_peer.c
index fb540141e08..81cc74adc91 100644
--- a/src/plugins/wireguard/wireguard_peer.c
+++ b/src/plugins/wireguard/wireguard_peer.c
@@ -46,7 +46,10 @@ wg_peer_endpoint_init (wg_peer_endpoint_t *ep, const ip46_address_t *addr,
 static void
 wg_peer_clear (vlib_main_t * vm, wg_peer_t * peer)
 {
+  index_t perri = peer - wg_peer_pool;
   wg_timers_stop (peer);
+  wg_peer_update_flags (perri, WG_PEER_ESTABLISHED, false);
+  wg_peer_update_flags (perri, WG_PEER_STATUS_DEAD, true);
   for (int i = 0; i < WG_N_TIMERS; i++)
     {
       peer->timers[i] = ~0;
@@ -80,7 +83,6 @@ wg_peer_clear (vlib_main_t * vm, wg_peer_t * peer)
   peer->new_handshake_interval_tick = 0;
   peer->rehandshake_interval_tick = 0;
   peer->timer_need_another_keepalive = false;
-  peer->is_dead = true;
   vec_free (peer->allowed_ips);
   vec_free (peer->adj_indices);
 }
@@ -88,6 +90,8 @@ wg_peer_clear (vlib_main_t * vm, wg_peer_t * peer)
 static void
 wg_peer_init (vlib_main_t * vm, wg_peer_t * peer)
 {
+  peer->api_client_by_client_index = hash_create (0, sizeof (u32));
+  peer->api_clients = NULL;
   wg_peer_clear (vm, peer);
 }
 
@@ -302,6 +306,7 @@ wg_peer_fill (vlib_main_t *vm, wg_peer_t *peer, u32 table_id,
 	      u16 persistent_keepalive_interval,
 	      const fib_prefix_t *allowed_ips, u32 wg_sw_if_index)
 {
+  index_t perri = peer - wg_peer_pool;
   wg_peer_endpoint_init (&peer->dst, dst, port);
 
   peer->table_id = table_id;
@@ -309,7 +314,7 @@ wg_peer_fill (vlib_main_t *vm, wg_peer_t *peer, u32 table_id,
   peer->timer_wheel = &wg_main.timer_wheel;
   peer->persistent_keepalive_interval = persistent_keepalive_interval;
   peer->last_sent_handshake = vlib_time_now (vm) - (REKEY_TIMEOUT + 1);
-  peer->is_dead = false;
+  wg_peer_update_flags (perri, WG_PEER_STATUS_DEAD, false);
 
   const wg_if_t *wgi = wg_if_get (wg_if_find_by_sw_if_index (wg_sw_if_index));
 
@@ -329,7 +334,6 @@ wg_peer_fill (vlib_main_t *vm, wg_peer_t *peer, u32 table_id,
     peer->allowed_ips[ii] = allowed_ips[ii];
   }
 
-  index_t perri = peer - wg_peer_pool;
   fib_protocol_t proto;
   FOR_EACH_FIB_IP_PROTOCOL (proto)
   {
@@ -338,6 +342,19 @@ wg_peer_fill (vlib_main_t *vm, wg_peer_t *peer, u32 table_id,
   return (0);
 }
 
+void
+wg_peer_update_flags (index_t peeri, wg_peer_flags flag, bool add_del)
+{
+  wg_peer_t *peer = wg_peer_get (peeri);
+  if ((add_del && (peer->flags & flag)) || (!add_del && !(peer->flags & flag)))
+    {
+      return;
+    }
+
+  peer->flags ^= flag;
+  wg_api_peer_event (peeri, peer->flags);
+}
+
 int
 wg_peer_add (u32 tun_sw_if_index, const u8 public_key[NOISE_PUBLIC_KEY_LEN],
 	     u32 table_id, const ip46_address_t *endpoint,
@@ -388,6 +405,7 @@ wg_peer_add (u32 tun_sw_if_index, const u8 public_key[NOISE_PUBLIC_KEY_LEN],
 		     wg_if->local_idx);
   cookie_maker_init (&peer->cookie_maker, public_key);
 
+  wg_send_handshake (vm, peer, false);
   if (peer->persistent_keepalive_interval != 0)
     {
       wg_send_keepalive (vm, peer);
@@ -459,14 +477,17 @@ format_wg_peer (u8 * s, va_list * va)
   peer = wg_peer_get (peeri);
   key_to_base64 (peer->remote.r_public, NOISE_PUBLIC_KEY_LEN, key);
 
-  s = format (s, "[%d] endpoint:[%U->%U] %U keep-alive:%d", peeri,
-	      format_wg_peer_endpoint, &peer->src, format_wg_peer_endpoint,
-	      &peer->dst, format_vnet_sw_if_index_name, vnet_get_main (),
-	      peer->wg_sw_if_index, peer->persistent_keepalive_interval);
+  s = format (
+    s,
+    "[%d] endpoint:[%U->%U] %U keep-alive:%d flags: %d, api-clients count: %d",
+    peeri, format_wg_peer_endpoint, &peer->src, format_wg_peer_endpoint,
+    &peer->dst, format_vnet_sw_if_index_name, vnet_get_main (),
+    peer->wg_sw_if_index, peer->persistent_keepalive_interval, peer->flags,
+    pool_elts (peer->api_clients));
   s = format (s, "\n  adj:");
   vec_foreach (adj_index, peer->adj_indices)
     {
-      s = format (s, " %d", adj_index);
+      s = format (s, " %d", *adj_index);
     }
   s = format (s, "\n  key:%=s %U", key, format_hex_bytes,
 	      peer->remote.r_public, NOISE_PUBLIC_KEY_LEN);
diff --git a/src/plugins/wireguard/wireguard_peer.h b/src/plugins/wireguard/wireguard_peer.h
index c719ac19511..a08fff73d68 100644
--- a/src/plugins/wireguard/wireguard_peer.h
+++ b/src/plugins/wireguard/wireguard_peer.h
@@ -17,6 +17,8 @@
 #ifndef __included_wg_peer_h__
 #define __included_wg_peer_h__
 
+#include <vlibapi/api_helper_macros.h>
+
 #include <vnet/ip/ip.h>
 
 #include <wireguard/wireguard_cookie.h>
@@ -46,6 +48,12 @@ typedef struct wg_peer_endpoint_t_
   u16 port;
 } wg_peer_endpoint_t;
 
+typedef enum
+{
+  WG_PEER_STATUS_DEAD = 0x1,
+  WG_PEER_ESTABLISHED = 0x2,
+} wg_peer_flags;
+
 typedef struct wg_peer
 {
   noise_remote_t remote;
@@ -69,6 +77,11 @@ typedef struct wg_peer
   /* The WG interface this peer is attached to */
   u32 wg_sw_if_index;
 
+  /* API client registered for events */
+  vpe_client_registration_t *api_clients;
+  uword *api_client_by_client_index;
+  wg_peer_flags flags;
+
   /* Timers */
   tw_timer_wheel_16t_2w_512sl_t *timer_wheel;
   u32 timers[WG_N_TIMERS];
@@ -88,8 +101,6 @@ typedef struct wg_peer
   u32 rehandshake_interval_tick;
 
   bool timer_need_another_keepalive;
-
-  bool is_dead;
 } wg_peer_t;
 
 typedef struct wg_peer_table_bind_ctx_t_
@@ -117,6 +128,15 @@ walk_rc_t wg_peer_if_delete (index_t peeri, void *data);
 walk_rc_t wg_peer_if_adj_change (index_t peeri, void *data);
 adj_walk_rc_t wg_peer_adj_walk (adj_index_t ai, void *data);
 
+void wg_api_peer_event (index_t peeri, wg_peer_flags flags);
+void wg_peer_update_flags (index_t peeri, wg_peer_flags flag, bool add_del);
+
+static inline bool
+wg_peer_is_dead (wg_peer_t *peer)
+{
+  return peer && peer->flags & WG_PEER_STATUS_DEAD;
+}
+
 /*
  * Expoed for the data-plane
  */
diff --git a/src/plugins/wireguard/wireguard_send.c b/src/plugins/wireguard/wireguard_send.c
index 4451e000776..a5f81774a19 100644
--- a/src/plugins/wireguard/wireguard_send.c
+++ b/src/plugins/wireguard/wireguard_send.c
@@ -106,8 +106,8 @@ wg_send_handshake (vlib_main_t * vm, wg_peer_t * peer, bool is_retry)
   if (!is_retry)
     peer->timer_handshake_attempts = 0;
 
-  if (!wg_birthdate_has_expired (peer->last_sent_handshake,
-				 REKEY_TIMEOUT) || peer->is_dead)
+  if (!wg_birthdate_has_expired (peer->last_sent_handshake, REKEY_TIMEOUT) ||
+      wg_peer_is_dead (peer))
     return true;
 
   if (noise_create_initiation (vm,
@@ -199,6 +199,7 @@ wg_send_keepalive (vlib_main_t * vm, wg_peer_t * peer)
     }
   else if (PREDICT_FALSE (state == SC_FAILED))
     {
+      wg_peer_update_flags (peer - wg_peer_pool, WG_PEER_ESTABLISHED, false);
       ret = false;
       goto out;
     }
@@ -252,13 +253,11 @@ wg_send_handshake_response (vlib_main_t * vm, wg_peer_t * peer)
 	    return false;
 
 	  ip46_enqueue_packet (vm, bi0, is_ip4);
+	  return true;
 	}
-      else
-	return false;
+      return false;
     }
-  else
-    return false;
-  return true;
+  return false;
 }
 
 /*
diff --git a/src/plugins/wireguard/wireguard_timer.c b/src/plugins/wireguard/wireguard_timer.c
index b245b853fb5..97c861b459c 100644
--- a/src/plugins/wireguard/wireguard_timer.c
+++ b/src/plugins/wireguard/wireguard_timer.c
@@ -191,7 +191,7 @@ wg_expired_zero_key_material (vlib_main_t * vm, wg_peer_t * peer)
       return;
     }
 
-  if (!peer->is_dead)
+  if (!wg_peer_is_dead (peer))
     {
       noise_remote_clear (vm, &peer->remote);
     }