Systemd/src/core/hostname-setup.c
Lennart Poettering f35cb39ed6 hostname-util: rework read_hostname_config() a bit
First of all, let's rename it to read_etc_hostname(), to make clearer
what kind of configuration it actually reads: the file format defined in
/etc/hostname and nothing else.

Secondly: let's port this to use read_line(), i.e. the new way to read
lines from a file in a safe, bounded way.

Thirdly: let's strip leading/trailing whitespace from what we are
reading. Given that we are already pretty lenient what we read (comments
and empty lines), let's be permissive regarding whitespace too.

Fourthly: let's actually validate the hostname when reading it. So far
we tried to make it valid, but that's not always possible (for example,
we can't make an empty hostname valid, ever).
2017-11-20 16:43:15 +01:00

70 lines
2 KiB
C

/* SPDX-License-Identifier: LGPL-2.1+ */
/***
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 <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include "alloc-util.h"
#include "fileio.h"
#include "hostname-setup.h"
#include "hostname-util.h"
#include "log.h"
#include "macro.h"
#include "string-util.h"
#include "util.h"
int hostname_setup(void) {
_cleanup_free_ char *b = NULL;
bool enoent = false;
const char *hn;
int r;
r = read_etc_hostname(NULL, &b);
if (r < 0) {
if (r == -ENOENT)
enoent = true;
else
log_warning_errno(r, "Failed to read configured hostname: %m");
hn = NULL;
} else
hn = b;
if (isempty(hn)) {
/* Don't override the hostname if it is already set
* and not explicitly configured */
if (hostname_is_set())
return 0;
if (enoent)
log_info("No hostname configured.");
hn = FALLBACK_HOSTNAME;
}
r = sethostname_idempotent(hn);
if (r < 0)
return log_warning_errno(r, "Failed to set hostname to <%s>: %m", hn);
log_info("Set hostname to <%s>.", hn);
return 0;
}