src/hostname-setup.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
   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 #if defined(TARGET_FEDORA) || defined(TARGET_ALTLINUX) || defined(TARGET_MANDRIVA)
  34 #define FILENAME "/etc/sysconfig/network"
  35 #elif defined(TARGET_SUSE) || defined(TARGET_SLACKWARE) || defined(TARGET_FRUGALWARE)
  36 #define FILENAME "/etc/HOSTNAME"
  37 #elif defined(TARGET_ARCH)
  38 #define FILENAME "/etc/rc.conf"
  39 #elif defined(TARGET_GENTOO)
  40 #define FILENAME "/etc/conf.d/hostname"
  41 #endif
  42
  43 static char* strip_bad_chars(char *s) {
  44         char *p, *d;
  45
  46         for (p = s, d = s; *p; p++)
  47                 if ((*p >= 'a' && *p <= 'z') ||
  48                     (*p >= 'A' && *p <= 'Z') ||
  49                     (*p >= '0' && *p <= '9') ||
  50                     *p == '-' ||
  51                     *p == '_' ||
  52                     *p == '.')
  53                         *(d++) = *p;
  54
  55         *d = 0;
  56
  57         return s;
  58 }
  59
  60 static int read_and_strip_hostname(const char *path, char **hn) {
  61         char *s, *k;
  62         int r;
  63
  64         assert(path);
  65         assert(hn);
  66
  67         if ((r = read_one_line_file(path, &s)) < 0)
  68                 return r;
  69
  70         k = strdup(strstrip(s));
  71         free(s);
  72
  73         if (!k)
  74                 return -ENOMEM;
  75
  76         strip_bad_chars(k);
  77
  78         if (k[0] == 0) {
  79                 free(k);
  80                 return -ENOENT;
  81         }
  82
  83         *hn = k;
  84
  85         return 0;
  86 }
  87
  88 static int read_distro_hostname(char **hn) {
  89
  90 #if defined(TARGET_FEDORA) || defined(TARGET_ARCH) || defined(TARGET_GENTOO) || defined(TARGET_ALTLINUX) || defined(TARGET_MANDRIVA)
  91         int r;
  92         FILE *f;
  93
  94         assert(hn);
  95
  96         if (!(f = fopen(FILENAME, "re")))
  97                 return -errno;
  98
  99         for (;;) {
 100                 char line[LINE_MAX];
 101                 char *s, *k;
 102
 103                 if (!fgets(line, sizeof(line), f)) {
 104                         if (feof(f))
 105                                 break;
 106
 107                         r = -errno;
 108                         goto finish;
 109                 }
 110
 111                 s = strstrip(line);
 112
 113                 if (!startswith_no_case(s, "HOSTNAME="))
 114                         continue;
 115
 116                 if (!(k = strdup(s+9))) {
 117                         r = -ENOMEM;
 118                         goto finish;
 119                 }
 120
 121                 strip_bad_chars(k);
 122
 123                 if (k[0] == 0) {
 124                         free(k);
 125                         r = -ENOENT;
 126                         goto finish;
 127                 }
 128
 129                 *hn = k;
 130                 r = 0;
 131                 goto finish;
 132         }
 133
 134         r = -ENOENT;
 135
 136 finish:
 137         fclose(f);
 138         return r;
 139
 140 #elif defined(TARGET_SUSE) || defined(TARGET_SLACKWARE) || defined(TARGET_FRUGALWARE)
 141         return read_and_strip_hostname(FILENAME, hn);
 142 #else
 143         return -ENOENT;
 144 #endif
 145 }
 146
 147 static int read_hostname(char **hn) {
 148         int r;
 149
 150         assert(hn);
 151
 152         /* First, try to load the generic hostname configuration file,
 153          * that we support on all distributions */
 154
 155         if ((r = read_and_strip_hostname("/etc/hostname", hn)) < 0) {
 156
 157                 if (r == -ENOENT)
 158                         return read_distro_hostname(hn);
 159
 160                 return r;
 161         }
 162
 163         return 0;
 164 }
 165
 166 int hostname_setup(void) {
 167         int r;
 168         char *b = NULL;
 169         const char *hn = NULL;
 170
 171         if ((r = read_hostname(&b)) < 0) {
 172                 if (r == -ENOENT)
 173                         log_info("No hostname configured.");
 174                 else
 175                         log_warning("Failed to read configured hostname: %s", strerror(-r));
 176
 177                 hn = "localhost";
 178         } else
 179                 hn = b;
 180
 181         if (sethostname(hn, strlen(hn)) < 0) {
 182                 log_warning("Failed to set hostname to <%s>: %m", hn);
 183                 r = -errno;
 184         } else
 185                 log_info("Set hostname to <%s>.", hn);
 186
 187         free(b);
 188
 189         return r;
 190 }