src/rc-local-generator/rc-local-generator.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2010 Lennart Poettering
   7   Copyright 2011 Michal Schmidt
   8
   9   systemd is free software; you can redistribute it and/or modify it
  10   under the terms of the GNU Lesser General Public License as published by
  11   the Free Software Foundation; either version 2.1 of the License, or
  12   (at your option) any later version.
  13
  14   systemd is distributed in the hope that it will be useful, but
  15   WITHOUT ANY WARRANTY; without even the implied warranty of
  16   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  17   Lesser General Public License for more details.
  18
  19   You should have received a copy of the GNU Lesser General Public License
  20   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  21 ***/
  22
  23 #include <errno.h>
  24 #include <stdio.h>
  25 #include <unistd.h>
  26
  27 #include "log.h"
  28 #include "util.h"
  29 #include "mkdir.h"
  30
  31 #ifndef RC_LOCAL_SCRIPT_PATH_START
  32 #define RC_LOCAL_SCRIPT_PATH_START "/etc/rc.d/rc.local"
  33 #endif
  34
  35 #ifndef RC_LOCAL_SCRIPT_PATH_STOP
  36 #define RC_LOCAL_SCRIPT_PATH_STOP "/sbin/halt.local"
  37 #endif
  38
  39 const char *arg_dest = "/tmp";
  40
  41 static int add_symlink(const char *service, const char *where) {
  42         char *from = NULL, *to = NULL;
  43         int r;
  44
  45         assert(service);
  46
  47         asprintf(&from, SYSTEM_DATA_UNIT_PATH "/%s", service);
  48         asprintf(&to, "%s/%s.wants/%s", arg_dest, where, service);
  49
  50         if (!from || !to) {
  51                 r = log_oom();
  52                 goto finish;
  53         }
  54
  55         mkdir_parents_label(to, 0755);
  56
  57         r = symlink(from, to);
  58         if (r < 0) {
  59                 if (errno == EEXIST)
  60                         r = 0;
  61                 else {
  62                         log_error("Failed to create symlink from %s to %s: %m", from, to);
  63                         r = -errno;
  64                 }
  65         }
  66
  67 finish:
  68         free(from);
  69         free(to);
  70
  71         return r;
  72 }
  73
  74 static bool file_is_executable(const char *f) {
  75         struct stat st;
  76
  77         if (stat(f, &st) < 0)
  78                 return false;
  79
  80         return S_ISREG(st.st_mode) && (st.st_mode & 0111);
  81 }
  82
  83 int main(int argc, char *argv[]) {
  84         int r = EXIT_SUCCESS;
  85
  86         if (argc > 1 && argc != 4) {
  87                 log_error("This program takes three or no arguments.");
  88                 return EXIT_FAILURE;
  89         }
  90
  91         if (argc > 1)
  92                 arg_dest = argv[1];
  93
  94         log_set_target(LOG_TARGET_SAFE);
  95         log_parse_environment();
  96         log_open();
  97
  98         umask(0022);
  99
 100         if (file_is_executable(RC_LOCAL_SCRIPT_PATH_START)) {
 101                 log_debug("Automatically adding rc-local.service.");
 102
 103                 if (add_symlink("rc-local.service", "multi-user.target") < 0)
 104                         r = EXIT_FAILURE;
 105         }
 106
 107         if (file_is_executable(RC_LOCAL_SCRIPT_PATH_STOP)) {
 108                 log_debug("Automatically adding halt-local.service.");
 109
 110                 if (add_symlink("halt-local.service", "final.target") < 0)
 111                         r = EXIT_FAILURE;
 112         }
 113
 114         return r;
 115 }