Implements undo command and optional timeout for configuration

Several new configure command variants:

configure undo - undo last reconfiguration
configure timeout - configure with scheduled undo if not confirmed in timeout
configure confirm - confirm last configuration
configure check - just parse and validate config file

sysdep/unix/config.Y

@@ -14,9 +14,9 @@ CF_HDR
 CF_DECLS
 
 CF_KEYWORDS(LOG, SYSLOG, ALL, DEBUG, TRACE, INFO, REMOTE, WARNING, ERROR, AUTH, FATAL, BUG, STDERR, SOFT)
-CF_KEYWORDS(TIMEFORMAT, ISO, SHORT, LONG, BASE, NAME)
+CF_KEYWORDS(TIMEFORMAT, ISO, SHORT, LONG, BASE, NAME, CONFIRM, UNDO, CHECK, TIMEOUT)
 
-%type <i> log_mask log_mask_list log_cat
+%type <i> log_mask log_mask_list log_cat cfg_timeout
 %type <g> log_file
 %type <t> cfg_name
 %type <tf> timeformat_which
@@ -104,13 +104,26 @@ timeformat_base:
 
 /* Unix specific commands */
 
-CF_CLI_HELP(CONFIGURE, [soft] [\"<file>\"], [[Reload configuration]])
+CF_CLI_HELP(CONFIGURE, ..., [[Reload configuration]])
 
-CF_CLI(CONFIGURE, cfg_name, [\"<file>\"], [[Reload configuration]])
-{ cmd_reconfig($2, RECONFIG_HARD); } ;
+CF_CLI(CONFIGURE, cfg_name cfg_timeout, [\"<file>\"] [timeout [<sec>]], [[Reload configuration]])
+{ cmd_reconfig($2, RECONFIG_HARD, $3); } ;
 
-CF_CLI(CONFIGURE SOFT, cfg_name, [\"<file>\"], [[Reload configuration and ignore changes in filters]])
-{ cmd_reconfig($3, RECONFIG_SOFT); } ;
+CF_CLI(CONFIGURE SOFT, cfg_name cfg_timeout, [\"<file>\"] [timeout [<sec>]], [[Reload configuration and ignore changes in filters]])
+{ cmd_reconfig($3, RECONFIG_SOFT, $4); } ;
+
+/* Hack to get input completion for 'timeout' */
+CF_CLI_CMD(CONFIGURE TIMEOUT, [<sec>], [[Reload configuration with undo timeout]])
+CF_CLI_CMD(CONFIGURE SOFT TIMEOUT, [<sec>], [[Reload configuration with undo timeout]])
+
+CF_CLI(CONFIGURE CONFIRM,,, [[Confirm last configuration change - deactivate undo timeout]])
+{ cmd_reconfig_confirm(); } ;
+
+CF_CLI(CONFIGURE UNDO,,, [[Undo last configuration change]])
+{ cmd_reconfig_undo(); } ;
+
+CF_CLI(CONFIGURE CHECK, cfg_name, [\"<file>\"], [[Parse configuration and check its validity]])
+{ cmd_check_config($3); } ;
 
 CF_CLI(DOWN,,, [[Shut the daemon down]])
 { cmd_shutdown(); } ;
@@ -120,6 +133,12 @@ cfg_name:
  | TEXT
  ;
 
+cfg_timeout:
+   /* empty */ { $$ = 0; }
+ | TIMEOUT { $$ = UNIX_DEFAULT_CONFIGURE_TIMEOUT; }
+ | TIMEOUT expr { $$ = $2; }
+ ;
+
 CF_CODE
 
 CF_END

sysdep/unix/io.c

@@ -121,7 +121,7 @@ static list near_timers, far_timers;
 static bird_clock_t first_far_timer = TIME_INFINITY;
 
 /* now must be different from 0, because 0 is a special value in timer->expires */
-bird_clock_t now = 1, now_real;
+bird_clock_t now = 1, now_real, boot_time;
 
 static void
 update_times_plain(void)
@@ -1530,6 +1530,7 @@ io_init(void)
   krt_io_init();
   init_times();
   update_times();
+  boot_time = now;
   srandom((int) now_real);
 }
 
@@ -1557,7 +1558,7 @@ io_loop(void)
 	  tm_shot();
 	  continue;
 	}
-      timo.tv_sec = events ? 0 : tout - now;
+      timo.tv_sec = events ? 0 : MIN(tout - now, 3);
       timo.tv_usec = 0;
 
       if (sock_recalc_fdsets_p)

sysdep/unix/krt.c

@@ -900,7 +900,7 @@ krt_notify(struct proto *P, struct rtable *table UNUSED, net *net,
 {
   struct krt_proto *p = (struct krt_proto *) P;
 
-  if (shutting_down)
+  if (config->shutdown)
     return;
   if (!(net->n.flags & KRF_INSTALLED))
     old = NULL;

sysdep/unix/main.c

@@ -210,7 +210,7 @@ read_config(void)
       else
 	die("Unable to open configuration file %s: %m", config_name);
     }
-  config_commit(conf, RECONFIG_HARD);
+  config_commit(conf, RECONFIG_HARD, 0);
 }
 
 void
@@ -228,19 +228,17 @@ async_config(void)
       config_free(conf);
     }
   else
-    config_commit(conf, RECONFIG_HARD);
+    config_commit(conf, RECONFIG_HARD, 0);
 }
 
-void
-cmd_reconfig(char *name, int type)
+static struct config *
+cmd_read_config(char *name)
 {
   struct config *conf;
 
-  if (cli_access_restricted())
-    return;
-
   if (!name)
     name = config_name;
+
   cli_msg(-2, "Reading configuration from %s", name);
   if (!unix_read_config(&conf, name))
     {
@@ -249,26 +247,96 @@ cmd_reconfig(char *name, int type)
       else
 	cli_msg(8002, "%s: %m", name);
       config_free(conf);
+      conf = NULL;
     }
-  else
+
+  return conf;
+}
+
+void
+cmd_check_config(char *name)
+{
+  struct config *conf = cmd_read_config(name);
+  if (!conf)
+    return;
+
+  cli_msg(20, "Configuration OK");
+  config_free(conf);
+}
+
+static void
+cmd_reconfig_msg(int r)
+{
+  switch (r)
     {
-      switch (config_commit(conf, type))
-	{
-	case CONF_DONE:
-	  cli_msg(3, "Reconfigured.");
-	  break;
-	case CONF_PROGRESS:
-	  cli_msg(4, "Reconfiguration in progress.");
-	  break;
-	case CONF_SHUTDOWN:
-	  cli_msg(6, "Reconfiguration ignored, shutting down.");
-	  break;
-	default:
-	  cli_msg(5, "Reconfiguration already in progress, queueing new config");
-	}
+    case CONF_DONE:	cli_msg( 3, "Reconfigured"); break;
+    case CONF_PROGRESS: cli_msg( 4, "Reconfiguration in progress"); break;
+    case CONF_QUEUED:	cli_msg( 5, "Reconfiguration already in progress, queueing new config"); break;
+    case CONF_UNQUEUED:	cli_msg(17, "Reconfiguration already in progress, removing queued config"); break;
+    case CONF_CONFIRM:	cli_msg(18, "Reconfiguration confirmed"); break;
+    case CONF_SHUTDOWN:	cli_msg( 6, "Reconfiguration ignored, shutting down"); break;
+    case CONF_NOTHING:	cli_msg(19, "Nothing to do"); break;
+    default:		break;
     }
 }
 
+/* Hack for scheduled undo notification */
+cli *cmd_reconfig_stored_cli;
+
+void
+cmd_reconfig_undo_notify(void)
+{
+  if (cmd_reconfig_stored_cli)
+    {
+      cli *c = cmd_reconfig_stored_cli;
+      cli_printf(c, CLI_ASYNC_CODE, "Config timeout expired, starting undo");
+      cli_write_trigger(c);
+    }
+}
+
+void
+cmd_reconfig(char *name, int type, int timeout)
+{
+  if (cli_access_restricted())
+    return;
+
+  struct config *conf = cmd_read_config(name);
+  if (!conf)
+    return;
+
+  int r = config_commit(conf, type, timeout);
+
+  if ((r >= 0) && (timeout > 0))
+    {
+      cmd_reconfig_stored_cli = this_cli;
+      cli_msg(-22, "Undo scheduled in %d s", timeout);
+    }
+
+  cmd_reconfig_msg(r);
+}
+
+void
+cmd_reconfig_confirm(void)
+{
+  if (cli_access_restricted())
+    return;
+
+  int r = config_confirm();
+  cmd_reconfig_msg(r);
+}
+
+void
+cmd_reconfig_undo(void)
+{
+  if (cli_access_restricted())
+    return;
+
+  cli_msg(-21, "Undo requested");
+
+  int r = config_undo();
+  cmd_reconfig_msg(r);
+}
+
 /*
  *	Command-Line Interface
  */
@@ -623,6 +691,7 @@ main(int argc, char **argv)
   rt_init();
   if_init();
   roa_init();
+  config_init();
 
   uid_t use_uid = get_uid(use_user);
   gid_t use_gid = get_gid(use_group);

sysdep/unix/timer.h

@@ -32,6 +32,7 @@ void tm_dump_all(void);
 
 extern bird_clock_t now; 		/* Relative, monotonic time in seconds */
 extern bird_clock_t now_real;		/* Time in seconds since fixed known epoch */
+extern bird_clock_t boot_time;
 
 static inline bird_clock_t
 tm_remains(timer *t)

sysdep/unix/unix.h

@@ -19,9 +19,14 @@ extern char *bird_name;
 void async_config(void);
 void async_dump(void);
 void async_shutdown(void);
-void cmd_reconfig(char *name, int type);
+void cmd_check_config(char *name);
+void cmd_reconfig(char *name, int type, int timeout);
+void cmd_reconfig_confirm(void);
+void cmd_reconfig_undo(void);
 void cmd_shutdown(void);
 
+#define UNIX_DEFAULT_CONFIGURE_TIMEOUT 300
+
 /* io.c */
 
 volatile int async_config_flag;