src/core/hostname-setup.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2
   3 #include <errno.h>
   4 #include <stdio.h>
   5 #include <stdlib.h>
   6
   7 #include "alloc-util.h"
   8 #include "fileio.h"
   9 #include "hostname-setup.h"
  10 #include "hostname-util.h"
  11 #include "log.h"
  12 #include "macro.h"
  13 #include "string-util.h"
  14 #include "util.h"
  15
  16 int hostname_setup(void) {
  17         _cleanup_free_ char *b = NULL;
  18         bool enoent = false;
  19         const char *hn;
  20         int r;
  21
  22         r = read_etc_hostname(NULL, &b);
  23         if (r < 0) {
  24                 if (r == -ENOENT)
  25                         enoent = true;
  26                 else
  27                         log_warning_errno(r, "Failed to read configured hostname: %m");
  28
  29                 hn = NULL;
  30         } else
  31                 hn = b;
  32
  33         if (isempty(hn)) {
  34                 /* Don't override the hostname if it is already set
  35                  * and not explicitly configured */
  36                 if (hostname_is_set())
  37                         return 0;
  38
  39                 if (enoent)
  40                         log_info("No hostname configured.");
  41
  42                 hn = FALLBACK_HOSTNAME;
  43         }
  44
  45         r = sethostname_idempotent(hn);
  46         if (r < 0)
  47                 return log_warning_errno(r, "Failed to set hostname to <%s>: %m", hn);
  48
  49         log_info("Set hostname to <%s>.", hn);
  50         return 0;
  51 }