src/core/hostname-setup.c

   1 /***
   2   This file is part of systemd.
   3
   4   Copyright 2010 Lennart Poettering
   5
   6   systemd is free software; you can redistribute it and/or modify it
   7   under the terms of the GNU Lesser General Public License as published by
   8   the Free Software Foundation; either version 2.1 of the License, or
   9   (at your option) any later version.
  10
  11   systemd is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   Lesser General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  18 ***/
  19
  20 #include <errno.h>
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23
  24 #include "alloc-util.h"
  25 #include "fileio.h"
  26 #include "hostname-setup.h"
  27 #include "hostname-util.h"
  28 #include "log.h"
  29 #include "macro.h"
  30 #include "string-util.h"
  31 #include "util.h"
  32
  33 int hostname_setup(void) {
  34         int r;
  35         _cleanup_free_ char *b = NULL;
  36         const char *hn;
  37         bool enoent = false;
  38
  39         r = read_hostname_config("/etc/hostname", &b);
  40         if (r < 0) {
  41                 if (r == -ENOENT)
  42                         enoent = true;
  43                 else
  44                         log_warning_errno(r, "Failed to read configured hostname: %m");
  45
  46                 hn = NULL;
  47         } else
  48                 hn = b;
  49
  50         if (isempty(hn)) {
  51                 /* Don't override the hostname if it is already set
  52                  * and not explicitly configured */
  53                 if (hostname_is_set())
  54                         return 0;
  55
  56                 if (enoent)
  57                         log_info("No hostname configured.");
  58
  59                 hn = "localhost";
  60         }
  61
  62         r = sethostname_idempotent(hn);
  63         if (r < 0)
  64                 return log_warning_errno(r, "Failed to set hostname to <%s>: %m", hn);
  65
  66         log_info("Set hostname to <%s>.", hn);
  67         return 0;
  68 }