hostname-setup: move to core/

[elogind.git] / src / core / hostname-setup.c

diff --git a/src/core/hostname-setup.c b/src/core/hostname-setup.c
new file mode 100644 (file)
index 0000000..550d3c2
--- /dev/null
+++ b/src/core/hostname-setup.c
@@ -0,0 +1,187 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright 2010 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <unistd.h>
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+#include <stdlib.h>
+
+#include "hostname-setup.h"
+#include "macro.h"
+#include "util.h"
+#include "log.h"
+
+#if defined(TARGET_FEDORA) || defined(TARGET_ALTLINUX) || defined(TARGET_MANDRIVA) || defined(TARGET_MEEGO) || defined(TARGET_MAGEIA)
+#define FILENAME "/etc/sysconfig/network"
+#elif defined(TARGET_SUSE) || defined(TARGET_SLACKWARE)
+#define FILENAME "/etc/HOSTNAME"
+#elif defined(TARGET_ARCH)
+#define FILENAME "/etc/rc.conf"
+#elif defined(TARGET_GENTOO)
+#define FILENAME "/etc/conf.d/hostname"
+#endif
+
+static int read_and_strip_hostname(const char *path, char **hn) {
+        char *s;
+        int r;
+
+        assert(path);
+        assert(hn);
+
+        if ((r = read_one_line_file(path, &s)) < 0)
+                return r;
+
+        hostname_cleanup(s);
+
+        if (isempty(s)) {
+                free(s);
+                return -ENOENT;
+        }
+
+        *hn = s;
+
+        return 0;
+}
+
+static int read_distro_hostname(char **hn) {
+
+#if defined(TARGET_FEDORA) || defined(TARGET_ARCH) || defined(TARGET_GENTOO) || defined(TARGET_ALTLINUX) || defined(TARGET_MANDRIVA) || defined(TARGET_MEEGO) || defined(TARGET_MAGEIA)
+        int r;
+        FILE *f;
+
+        assert(hn);
+
+        if (!(f = fopen(FILENAME, "re")))
+                return -errno;
+
+        for (;;) {
+                char line[LINE_MAX];
+                char *s, *k;
+
+                if (!fgets(line, sizeof(line), f)) {
+                        if (feof(f))
+                                break;
+
+                        r = -errno;
+                        goto finish;
+                }
+
+                s = strstrip(line);
+
+                if (!startswith_no_case(s, "HOSTNAME="))
+                        continue;
+
+                if (!(k = strdup(s+9))) {
+                        r = -ENOMEM;
+                        goto finish;
+                }
+
+                hostname_cleanup(k);
+
+                if (isempty(k)) {
+                        free(k);
+                        r = -ENOENT;
+                        goto finish;
+                }
+
+                *hn = k;
+                r = 0;
+                goto finish;
+        }
+
+        r = -ENOENT;
+
+finish:
+        fclose(f);
+        return r;
+
+#elif defined(TARGET_SUSE) || defined(TARGET_SLACKWARE)
+        return read_and_strip_hostname(FILENAME, hn);
+#else
+        return -ENOENT;
+#endif
+}
+
+static int read_hostname(char **hn) {
+        int r;
+
+        assert(hn);
+
+        /* First, try to load the generic hostname configuration file,
+         * that we support on all distributions */
+
+        if ((r = read_and_strip_hostname("/etc/hostname", hn)) < 0) {
+
+                if (r == -ENOENT)
+                        return read_distro_hostname(hn);
+
+                return r;
+        }
+
+        return 0;
+}
+
+int hostname_setup(void) {
+        int r;
+        char *b = NULL;
+        const char *hn = NULL;
+
+        if ((r = read_hostname(&b)) < 0) {
+                if (r == -ENOENT)
+                        log_info("No hostname configured.");
+                else
+                        log_warning("Failed to read configured hostname: %s", strerror(-r));
+
+                hn = NULL;
+        } else
+                hn = b;
+
+        if (!hn) {
+                /* Don't override the hostname if it is unset and not
+                 * explicitly configured */
+
+                char *old_hostname = NULL;
+
+                if ((old_hostname = gethostname_malloc())) {
+                        bool already_set;
+
+                        already_set = old_hostname[0] != 0;
+                        free(old_hostname);
+
+                        if (already_set)
+                                goto finish;
+                }
+
+                hn = "localhost";
+        }
+
+        if (sethostname(hn, strlen(hn)) < 0) {
+                log_warning("Failed to set hostname to <%s>: %m", hn);
+                r = -errno;
+        } else
+                log_info("Set hostname to <%s>.", hn);
+
+finish:
+        free(b);
+
+        return r;
+}