hostname-setup.c

   1 /*-*- Mode: C; c-basic-offset: 8 -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2010 Lennart Poettering
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU General Public License as published by
  10   the Free Software Foundation; either version 2 of the License, or
  11   (at your option) any later version.
  12
  13   systemd is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   General Public License for more details.
  17
  18   You should have received a copy of the GNU General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include <unistd.h>
  23 #include <stdio.h>
  24 #include <errno.h>
  25 #include <string.h>
  26 #include <stdlib.h>
  27
  28 #include "hostname-setup.h"
  29 #include "macro.h"
  30 #include "util.h"
  31 #include "log.h"
  32
  33 #define LINE_MAX 4096
  34
  35 static int read_hostname(char **hn) {
  36
  37 #if defined(TARGET_FEDORA)
  38         int r;
  39         FILE *f;
  40
  41         assert(hn);
  42
  43         if (!(f = fopen("/etc/sysconfig/network", "re")))
  44                 return -errno;
  45
  46         for (;;) {
  47                 char line[LINE_MAX];
  48                 char *s, *k;
  49
  50                 if (!fgets(line, sizeof(line), f)) {
  51                         if (feof(f))
  52                                 break;
  53
  54                         r = -errno;
  55                         goto finish;
  56                 }
  57
  58                 s = strstrip(line);
  59
  60                 if (!startswith(s, "HOSTNAME="))
  61                         continue;
  62
  63                 if (!(k = strdup(s+9))) {
  64                         r = -ENOMEM;
  65                         goto finish;
  66                 }
  67
  68                 *hn = k;
  69                 break;
  70         }
  71
  72         r = 0;
  73
  74 finish:
  75         fclose(f);
  76         return r;
  77
  78 #elif defined(TARGET_SUSE)
  79         int r;
  80         char *s, *k;
  81
  82         assert(hn);
  83
  84         if ((r = read_one_line_file("/etc/HOSTNAME", &s)) < 0)
  85                 return r;
  86
  87         k = strdup(strstrip(s));
  88         free(s);
  89
  90         if (!k)
  91                 return -ENOMEM;
  92
  93         *hn = k;
  94
  95 #elif defined(TARGET_DEBIAN)
  96         int r;
  97         char *s, *k;
  98
  99         assert(hn);
 100
 101         if ((r = read_one_line_file("/etc/hostname", &s)) < 0)
 102                 return r;
 103
 104         k = strdup(strstrip(s));
 105         free(s);
 106
 107         if (!k)
 108                 return -ENOMEM;
 109
 110         *hn = k;
 111 #else
 112 #warning "Don't know how to read the hostname"
 113
 114         return -ENOENT;
 115 #endif
 116
 117         return 0;
 118 }
 119
 120 int hostname_setup(void) {
 121         int r;
 122         char *hn;
 123
 124         if ((r = read_hostname(&hn)) < 0) {
 125                 if (r != -ENOENT)
 126                         log_warning("Failed to read configured hostname: %s", strerror(-r));
 127
 128                 return r;
 129         }
 130
 131         r = sethostname(hn, strlen(hn)) < 0 ? -errno : 0;
 132
 133         if (r < 0)
 134                 log_warning("Failed to set hostname to <%s>: %s", hn, strerror(-r));
 135         else
 136                 log_info("Set hostname to <%s>.", hn);
 137
 138         free(hn);
 139
 140         return r;
 141 }