4 files changed, 37 insertions, 0 deletions

diff --git a/manage.c b/manage.c
index 4248787..7eff627 100644
--- a/manage.c
+++ b/manage.c
@@ -916,6 +916,20 @@ man_client_kill (struct management *man, const char *cid_str)
     }
 }
 
+static void
+man_client_n_clients (struct management *man)
+{
+  if (man->persist.callback.n_clients)
+    {
+      const int nclients = (*man->persist.callback.n_clients) (man->persist.callback.arg);
+      msg (M_CLIENT, "SUCCESS: nclients=%d", nclients);
+    }
+  else
+    {
+      msg (M_CLIENT, "ERROR: The nclients command is not supported by the current daemon mode");
+    }
+}
+
 #ifdef MANAGEMENT_PF
 
 static void
@@ -981,6 +995,10 @@ man_dispatch_command (struct management *man, struct status_output *so, const ch
     {
       msg (M_CLIENT, "SUCCESS: pid=%d", openvpn_getpid ());
     }
+  else if (streq (p[0], "nclients"))
+    {
+      man_client_n_clients (man);
+    }
   else if (streq (p[0], "signal"))
     {
       if (man_need (man, p, 1, 0))
diff --git a/manage.h b/manage.h
index e8ae93b..94ec639 100644
--- a/manage.h
+++ b/manage.h
@@ -154,6 +154,7 @@ struct management_callback
   int (*kill_by_cn) (void *arg, const char *common_name);
   int (*kill_by_addr) (void *arg, const in_addr_t addr, const int port);
   void (*delete_event) (void *arg, event_t event);
+  int (*n_clients) (void *arg);
 #ifdef MANAGEMENT_DEF_AUTH
   bool (*kill_by_cid) (void *arg, const unsigned long cid);
   bool (*client_auth) (void *arg,
diff --git a/multi.c b/multi.c
index 733a8b0..6704789 100644
--- a/multi.c
+++ b/multi.c
@@ -503,6 +503,10 @@ multi_close_instance (struct multi_context *m,
 
   dmsg (D_MULTI_DEBUG, "MULTI: multi_close_instance called");
 
+  /* adjust current client connection count */
+  m->n_clients += mi->n_clients_delta;
+  mi->n_clients_delta = 0;
+
   /* prevent dangling pointers */
   if (m->pending == mi)
     multi_set_pending (m, NULL);
@@ -1688,6 +1692,10 @@ multi_connection_established (struct multi_context *m, struct multi_instance *mi
       /* set flag so we don't get called again */
       mi->connection_established_flag = true;
 
+      /* increment number of current authenticated clients */
+      ++m->n_clients;
+      --mi->n_clients_delta;
+
 #ifdef MANAGEMENT_DEF_AUTH
       if (management)
 	management_connection_established (management, &mi->context.c2.mda_context);
@@ -2437,6 +2445,13 @@ management_callback_status (void *arg, const int version, struct status_output *
 }
 
 static int
+management_callback_n_clients (void *arg)
+{
+  struct multi_context *m = (struct multi_context *) arg;
+  return m->n_clients;
+}
+
+static int
 management_callback_kill_by_cn (void *arg, const char *del_cn)
 {
   struct multi_context *m = (struct multi_context *) arg;
@@ -2598,6 +2613,7 @@ init_management_callback_multi (struct multi_context *m)
       cb.kill_by_cn = management_callback_kill_by_cn;
       cb.kill_by_addr = management_callback_kill_by_addr;
       cb.delete_event = management_delete_event;
+      cb.n_clients = management_callback_n_clients;
 #ifdef MANAGEMENT_DEF_AUTH
       cb.kill_by_cid = management_kill_by_cid;
       cb.client_auth = management_client_auth;
diff --git a/multi.h b/multi.h
index 7c33d87..55119d6 100644
--- a/multi.h
+++ b/multi.h
@@ -83,6 +83,7 @@ struct multi_instance {
 #endif
   bool connection_established_flag;
   bool did_iroutes;
+  int n_clients_delta; /* added to multi_context.n_clients when instance is closed */
 
   struct context context;
 };
@@ -114,6 +115,7 @@ struct multi_context {
   int max_clients;
   int tcp_queue_limit;
   int status_file_version;
+  int n_clients; /* current number of authenticated clients */
 
 #ifdef MANAGEMENT_DEF_AUTH
   struct hash *cid_hash;