hostname: set hostname early during boottime

1 files changed, 124 insertions, 0 deletions

diff --git a/hostname-setup.c b/hostname-setup.c
new file mode 100644
index 0000000000..eca33a9853
--- /dev/null
+++ b/hostname-setup.c
@@ -0,0 +1,124 @@
+/*-*- Mode: C; c-basic-offset: 8 -*-*/
+
+/***
+  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 General Public License as published by
+  the Free Software Foundation; either version 2 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
+  General Public License for more details.
+
+  You should have received a copy of the GNU 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"
+
+#define LINE_MAX 4096
+
+static int read_hostname(char **hn) {
+
+#if defined(TARGET_FEDORA)
+        int r;
+        FILE *f;
+
+        assert(hn);
+
+        if (!(f = fopen("/etc/sysconfig/network", "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(s, "HOSTNAME="))
+                        continue;
+
+                if (!(k = strdup(s+9))) {
+                        r = -ENOMEM;
+                        goto finish;
+                }
+
+                *hn = k;
+                break;
+        }
+
+        r = 0;
+
+finish:
+        fclose(f);
+        return r;
+
+#elif defined(TARGET_DEBIAN)
+        int r;
+        char *s, *k;
+
+        assert(hn);
+
+        if ((r = read_one_line_file("/etc/hostname", &s)) < 0)
+                return r;
+
+        k = strdup(strstrip(s));
+        free(s);
+
+        if (!k)
+                return -ENOMEM;
+
+        *hn = k;
+#else
+#warn "Don't know how to read the hostname"
+
+        return -ENOENT;
+#endif
+
+        return 0;
+}
+
+int hostname_setup(void) {
+        int r;
+        char *hn;
+
+        if ((r = read_hostname(&hn)) < 0) {
+                if (r != -ENOENT)
+                        log_warning("Failed to read configured hostname: %s", strerror(-r));
+
+                return r;
+        }
+
+        r = sethostname(hn, strlen(hn)) < 0 ? -errno : 0;
+
+        if (r < 0)
+                log_warning("Failed to set hostname to <%s>: %s", hn, strerror(-r));
+        else
+                log_info("Set hostname to <%s>.", hn);
+
+        free(hn);
+
+        return r;
+}