X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?p=gnupg2.git;a=blobdiff_plain;f=agent%2Fgpg-agent.c;h=121bb0ed4f6a7e8b9d3486c4855e3811776db57e;hp=82c8ae0621a443e604cb785711aaa16925f9e6a4;hb=refs%2Fheads%2F841143-bugfix;hpb=c224dda498a321a715e9f1a5e61c371d289f8657

diff --git a/agent/gpg-agent.c b/agent/gpg-agent.c
index 82c8ae0..121bb0e 100644
--- a/agent/gpg-agent.c
+++ b/agent/gpg-agent.c
@@ -316,10 +316,10 @@ static int startup_signal_mask_valid;
 #endif
 
 /* Flag to indicate that a shutdown was requested.  */
-static int shutdown_pending;
+static int shutdown_pending; /* xxx threaded accesses lack locking */
 
 /* Counter for the currently running own socket checks.  */
-static int check_own_socket_running;
+static int check_own_socket_running; /* xxx threaded accesses lack locking */
 
 /* Flags to indicate that check_own_socket shall not be called.  */
 static int disable_check_own_socket;
@@ -328,7 +328,7 @@ static int disable_check_own_socket;
 static int is_supervised;
 
 /* Flag to inhibit socket removal in cleanup.  */
-static int inhibit_socket_removal;
+static int inhibit_socket_removal; /* xxx threaded accesses lack locking */
 
 /* It is possible that we are currently running under setuid permissions */
 static int maybe_setuid = 1;
@@ -382,8 +382,12 @@ static char *current_logfile;
    watched. */
 static pid_t parent_pid = (pid_t)(-1);
 
+/* Record the pid of the main thread, for easier signalling */
+static pid_t main_thread_pid = (pid_t)(-1);
+
 /* Number of active connections.  */
-static int active_connections;
+static int active_connections_value;
+static npth_mutex_t active_connections_lock;
 
 /* This object is used to dispatch progress messages from Libgcrypt to
  * the right thread.  Given that we will have at max only a few dozen
@@ -1985,11 +1989,49 @@ get_agent_ssh_socket_name (void)
 }
 
 
+static void
+lock_active_connections (void)
+{
+  int err;
+
+  err = npth_mutex_lock (&active_connections_lock);
+  if (err)
+    log_fatal ("failed to acquire active connection count mutex: %s\n",
+	       strerror (err));
+}
+
+static void
+unlock_active_connections (void)
+{
+  int err;
+
+  err = npth_mutex_unlock (&active_connections_lock);
+  if (err)
+    log_fatal ("failed to release active connection count mutex: %s\n",
+	       strerror (err));
+}
+
 /* Return the number of active connections. */
 int
 get_agent_active_connection_count (void)
 {
-  return active_connections;
+  int value;
+
+  lock_active_connections();
+  value = active_connections_value;
+  unlock_active_connections();
+  return value;
+}
+
+/* Increment/decrement the number of active connections. */
+static void
+adjust_agent_active_connections (int delta)
+{
+  lock_active_connections();
+  active_connections_value += delta;
+  if (active_connections_value == 0)
+    interrupt_main_thread_loop ();
+  unlock_active_connections();
 }
 
 
@@ -2020,7 +2062,7 @@ get_agent_scd_notify_event (void)
                                  GetCurrentProcess(), &h2,
                                  EVENT_MODIFY_STATE|SYNCHRONIZE, TRUE, 0))
         {
-          log_error ("setting syncronize for scd notify event failed: %s\n",
+          log_error ("setting synchronize for scd notify event failed: %s\n",
                      w32_strerror (-1) );
           CloseHandle (h);
         }
@@ -2264,6 +2306,26 @@ create_directories (void)
 }
 
 
+static int
+need_tick (void)
+{
+#ifdef HAVE_W32_SYSTEM
+  /* We do not know how to interrupt the select loop on Windows, so we
+     always need a short tick there. */
+  return 1;
+#else
+  /* if we were invoked like "gpg-agent cmd arg1 arg2" then we need to
+     watch our parent. */
+  if (parent_pid != (pid_t)(-1))
+    return 1;
+  /* if scdaemon is running, we need to check that it's alive */
+  if (agent_scd_check_running ())
+    return 1;
+  /* otherwise, nothing fine-grained to do. */
+  return 0;
+#endif /*HAVE_W32_SYSTEM*/
+}
+
 
 /* This is the worker for the ticker.  It is called every few seconds
    and may only do fast operations. */
@@ -2322,7 +2384,7 @@ agent_sigusr2_action (void)
 
 #ifndef HAVE_W32_SYSTEM
 /* The signal handler for this program.  It is expected to be run in
-   its own trhead and not in the context of a signal handler.  */
+   its own thread and not in the context of a signal handler.  */
 static void
 handle_signal (int signo)
 {
@@ -2346,12 +2408,16 @@ handle_signal (int signo)
       agent_sigusr2_action ();
       break;
 
+      /* nothing to do here, just take an extra cycle on the select loop */
+    case SIGCONT:
+      break;
+
     case SIGTERM:
       if (!shutdown_pending)
         log_info ("SIGTERM received - shutting down ...\n");
       else
         log_info ("SIGTERM received - still %i open connections\n",
-		  active_connections);
+		  get_agent_active_connection_count());
       shutdown_pending++;
       if (shutdown_pending > 2)
         {
@@ -2586,7 +2652,7 @@ putty_message_thread (void *arg)
 static void *
 do_start_connection_thread (ctrl_t ctrl)
 {
-  active_connections++;
+  adjust_agent_active_connections(+1);
   agent_init_default_ctrl (ctrl);
   if (opt.verbose && !DBG_IPC)
     log_info (_("handler 0x%lx for fd %d started\n"),
@@ -2599,7 +2665,7 @@ do_start_connection_thread (ctrl_t ctrl)
 
   agent_deinit_default_ctrl (ctrl);
   xfree (ctrl);
-  active_connections--;
+  adjust_agent_active_connections(-1);
   return NULL;
 }
 
@@ -2666,7 +2732,7 @@ start_connection_thread_ssh (void *arg)
   if (check_nonce (ctrl, &socket_nonce_ssh))
     return NULL;
 
-  active_connections++;
+  adjust_agent_active_connections(+1);
   agent_init_default_ctrl (ctrl);
   if (opt.verbose)
     log_info (_("ssh handler 0x%lx for fd %d started\n"),
@@ -2679,11 +2745,18 @@ start_connection_thread_ssh (void *arg)
 
   agent_deinit_default_ctrl (ctrl);
   xfree (ctrl);
-  active_connections--;
+  adjust_agent_active_connections(-1);
   return NULL;
 }
 
 
+void interrupt_main_thread_loop (void)
+{
+#ifndef HAVE_W32_SYSTEM
+  kill (main_thread_pid, SIGCONT);
+#endif
+}
+
 /* helper function for readability: test whether a given struct
    timespec is set to all-zeros */
 static inline int
@@ -2739,6 +2812,10 @@ handle_connections (gnupg_fd_t listen_fd,
     { { CHECK_OWN_SOCKET_INTERVAL, 0 }, check_own_socket }
   };
 
+  ret = npth_mutex_init (&active_connections_lock, NULL);
+  if (ret)
+    log_fatal ("error allocating active connections mutex: %s\n",
+	       strerror (ret));
 
   ret = npth_attr_init(&tattr);
   if (ret)
@@ -2752,8 +2829,10 @@ handle_connections (gnupg_fd_t listen_fd,
   npth_sigev_add (SIGUSR1);
   npth_sigev_add (SIGUSR2);
   npth_sigev_add (SIGINT);
+  npth_sigev_add (SIGCONT);
   npth_sigev_add (SIGTERM);
   npth_sigev_fini ();
+  main_thread_pid = getpid ();
 #else
 # ifdef HAVE_W32CE_SYSTEM
   /* Use a dummy event. */
@@ -2765,6 +2844,7 @@ handle_connections (gnupg_fd_t listen_fd,
 # endif
 #endif
 
+
   if (disable_check_own_socket)
     my_inotify_fd = -1;
   else if ((err = gnupg_inotify_watch_socket (&my_inotify_fd, socket_name)))
@@ -2832,7 +2912,7 @@ handle_connections (gnupg_fd_t listen_fd,
       /* Shutdown test.  */
       if (shutdown_pending)
         {
-          if (active_connections == 0)
+          if (get_agent_active_connection_count() == 0)
             break; /* ready */
 
           /* Do not accept new connections but keep on running the
@@ -2855,6 +2935,11 @@ handle_connections (gnupg_fd_t listen_fd,
          thus a simple assignment is fine to copy the entire set.  */
       read_fdset = fdset;
 
+      /* avoid a fine-grained timer if we don't need one: */
+      timertbl[0].interval.tv_sec = need_tick () ? TIMERTICK_INTERVAL : 0;
+      /* avoid waking up to check sockets if we can count on inotify */
+      timertbl[1].interval.tv_sec = (my_inotify_fd == -1) ? CHECK_OWN_SOCKET_INTERVAL : 0;
+
       /* loop through all timers, fire any registered functions, and
          plan next timer to trigger */
       npth_clock_gettime (&curtime);