From 41b427e1b220389eccd65e436fc3452e2bc0215d Mon Sep 17 00:00:00 2001 From: Mathieu Lirzin Date: Wed, 27 Sep 2017 23:10:29 +0200 Subject: Revert "Taken on board suggestions of Mathieu Lirzin as per e-mails to the bug-mcron@gnu.org mailing list around September 2015." This reverts commit c0a6eb14c257a47e9573631e5ac09e6528fba377. --- mcron.c | 115 ---------------------------------------------------------------- 1 file changed, 115 deletions(-) delete mode 100644 mcron.c (limited to 'mcron.c') diff --git a/mcron.c b/mcron.c deleted file mode 100644 index 3776632..0000000 --- a/mcron.c +++ /dev/null @@ -1,115 +0,0 @@ -/* mcron.c -- Run the mcron program. - * - * Copyright (C) 2015 Mathieu Lirzin - * Copyright (C) 2003, 2014 Dale Mellor - * - * This file is part of GNU Mcron. - * - * GNU Mcron is free software: you can redistribute it and/or modify it under - * the terms of the GNU General Public License as published by the Free - * Software Foundation, either version 3 of the License, or (at your option) - * any later version. - * - * GNU Mcron is distributed in the hope that it will be useful, but WITHOUT - * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or - * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for - * more details. - * - * You should have received a copy of the GNU General Public License along - * with GNU Mcron. If not, see . - */ - - -/* - * This C code represents the thinnest possible wrapper around the Guile code - * which constitutes all the functionality of the mcron program. There are - * two plus one reasons why we need to do this, and one very unfortunate - * consequence. - * - * Firstly, SUID does not work on an executable script. In the end, it is - * the execution of the translator, in our case guile, which determines the - * effective user, and it is not wise to make the system guile installation - * SUID root! - * - * Secondly, executable scripts show up in ugly ways in listings of the - * system process table. Guile in particular, with its multi-line ``#! ...\ - * \n -s ...!#'' idiosyncracies shows up in process listings in a way that - * is difficult to determine what program is actually running. - * - * A third reason for the C wrapper which might be mentioned is that a - * security-conscious system administrator can choose to only install a - * binary, thus removing the possibility of a user studying a guile script - * and working out ways of hacking it to his own ends, or worse still - * finding a way to modify it to his own ends. - * - * Unfortunately, running the guile script from inside a C program means - * that the sigaction function does not work. Instead, it is necessary to - * perform the signal processing in C. - */ - - - -#include -#include -#include -#include - - - -/* Handle the signal and exit. All signals that mcron handles will produce - * the same behavior so we don't need to use the signal value in the - * implementation. */ - -static void -react_to_terminal_signal (int signal) -{ - scm_c_eval_string ("(delete-run-file)"); - exit (1); -} - - - -/* Set up all the signal handlers as required by the cron personality. This - * is necessary to perform the signal processing in C because the sigaction - * function won't work when called from Guile; this function is called from - * the Guile universe. */ - -static SCM -set_cron_signals () -{ - static struct sigaction sa; - - memset (&sa, 0, sizeof (sa)); - sa.sa_handler = react_to_terminal_signal; - sigaction (SIGTERM, &sa, 0); - sigaction (SIGINT, &sa, 0); - sigaction (SIGQUIT, &sa, 0); - sigaction (SIGHUP, &sa, 0); - - return SCM_BOOL_T; -} - - - -/* Launch the Mcron Guile main program. */ - -static void -inner_main (void *closure, int argc, char **argv) -{ - scm_set_current_module (scm_c_resolve_module ("mcron main")); - scm_c_define_gsubr ("c-set-cron-signals", 0, 0, 0, set_cron_signals); - scm_c_eval_string ("(main)"); -} - - - -/* The real main function. Does nothing but start up the guile subsystem. */ - -int -main (int argc, char **argv) -{ - setenv ("GUILE_LOAD_PATH", GUILE_LOAD_PATH, 1); - scm_boot_guile (argc, argv, inner_main, 0); - - return 0; -} -- cgit v1.2.3