agent: Fix long standing regression tracking the connection count.

* agent/gpg-agent.c (get_agent_active_connection_count): New.
(do_start_connection_thread, start_connection_thread_ssh): Bump
ACTIVE_CONNECTIONS up and down.
* agent/command.c (cmd_getinfo): Add subcommand "connections".
--

The variable ACTIVE_CONNECTIONS is used to shutdown gpg-agent in a
friendly way.  Before we switched to nPth a Pth provided count of
threads was used for this.  During the migration to nPth
ACTIVE_CONNECTIONS was introduced and checked but never set.

Signed-off-by: Werner Koch <wk@gnupg.org>

agent/agent.h

@@ -341,6 +341,7 @@ void agent_set_progress_cb (void (*cb)(ctrl_t ctrl, const char *what,
 gpg_error_t agent_copy_startup_env (ctrl_t ctrl);
 const char *get_agent_socket_name (void);
 const char *get_agent_ssh_socket_name (void);
+int get_agent_active_connection_count (void);
 #ifdef HAVE_W32_SYSTEM
 void *get_agent_scd_notify_event (void);
 #endif

agent/command.c

@@ -2775,6 +2775,7 @@ static const char hlp_getinfo[] =
   "  std_startup_env - List the standard startup environment.\n"
   "  cmd_has_option\n"
   "              - Returns OK if the command CMD implements the option OPT.\n"
+  "  connections - Return number of active connections.\n"
   "  restricted  - Returns OK if the connection is in restricted mode.\n";
 static gpg_error_t
 cmd_getinfo (assuan_context_t ctx, char *line)
@@ -2907,6 +2908,14 @@ cmd_getinfo (assuan_context_t ctx, char *line)
             }
         }
     }
+  else if (!strcmp (line, "connections"))
+    {
+      char numbuf[20];
+
+      snprintf (numbuf, sizeof numbuf, "%d",
+                get_agent_active_connection_count ());
+      rc = assuan_send_data (ctx, numbuf, strlen (numbuf));
+    }
   else
     rc = set_error (GPG_ERR_ASS_PARAMETER, "unknown value for WHAT");
   return rc;

agent/gpg-agent.c

@@ -1694,6 +1694,14 @@ get_agent_ssh_socket_name (void)
 }
 
 
+/* Return the number of active connections. */
+int
+get_agent_active_connection_count (void)
+{
+  return active_connections;
+}
+
+
 /* Under W32, this function returns the handle of the scdaemon
    notification event.  Calling it the first time creates that
    event.  */
@@ -2302,6 +2310,7 @@ putty_message_thread (void *arg)
 static void *
 do_start_connection_thread (ctrl_t ctrl)
 {
+  active_connections++;
   agent_init_default_ctrl (ctrl);
   if (opt.verbose)
     log_info (_("handler 0x%lx for fd %d started\n"),
@@ -2314,6 +2323,7 @@ do_start_connection_thread (ctrl_t ctrl)
 
   agent_deinit_default_ctrl (ctrl);
   xfree (ctrl);
+  active_connections--;
   return NULL;
 }
 
@@ -2380,6 +2390,7 @@ start_connection_thread_ssh (void *arg)
   if (check_nonce (ctrl, &socket_nonce_ssh))
     return NULL;
 
+  active_connections++;
   agent_init_default_ctrl (ctrl);
   if (opt.verbose)
     log_info (_("ssh handler 0x%lx for fd %d started\n"),
@@ -2392,6 +2403,7 @@ start_connection_thread_ssh (void *arg)
 
   agent_deinit_default_ctrl (ctrl);
   xfree (ctrl);
+  active_connections--;
   return NULL;
 }