1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
|
/* SPDX-License-Identifier: LGPL-2.1-or-later */
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/utsname.h>
#include <unistd.h>
#include "alloc-util.h"
#include "fd-util.h"
#include "fileio.h"
#include "fs-util.h"
#include "hostname-setup.h"
#include "hostname-util.h"
#include "log.h"
#include "macro.h"
#include "proc-cmdline.h"
#include "string-table.h"
#include "string-util.h"
#include "util.h"
static int sethostname_idempotent_full(const char *s, bool really) {
struct utsname u;
assert(s);
assert_se(uname(&u) >= 0);
if (streq_ptr(s, u.nodename))
return 0;
if (really &&
sethostname(s, strlen(s)) < 0)
return -errno;
return 1;
}
int sethostname_idempotent(const char *s) {
return sethostname_idempotent_full(s, true);
}
int shorten_overlong(const char *s, char **ret) {
char *h, *p;
/* Shorten an overlong name to HOST_NAME_MAX or to the first dot,
* whatever comes earlier. */
assert(s);
h = strdup(s);
if (!h)
return -ENOMEM;
if (hostname_is_valid(h, 0)) {
*ret = h;
return 0;
}
p = strchr(h, '.');
if (p)
*p = 0;
strshorten(h, HOST_NAME_MAX);
if (!hostname_is_valid(h, 0)) {
free(h);
return -EDOM;
}
*ret = h;
return 1;
}
int read_etc_hostname_stream(FILE *f, char **ret) {
int r;
assert(f);
assert(ret);
for (;;) {
_cleanup_free_ char *line = NULL;
char *p;
r = read_line(f, LONG_LINE_MAX, &line);
if (r < 0)
return r;
if (r == 0) /* EOF without any hostname? the file is empty, let's treat that exactly like no file at all: ENOENT */
return -ENOENT;
p = strstrip(line);
/* File may have empty lines or comments, ignore them */
if (!IN_SET(*p, '\0', '#')) {
char *copy;
hostname_cleanup(p); /* normalize the hostname */
if (!hostname_is_valid(p, VALID_HOSTNAME_TRAILING_DOT)) /* check that the hostname we return is valid */
return -EBADMSG;
copy = strdup(p);
if (!copy)
return -ENOMEM;
*ret = copy;
return 0;
}
}
}
int read_etc_hostname(const char *path, char **ret) {
_cleanup_fclose_ FILE *f = NULL;
assert(ret);
if (!path)
path = "/etc/hostname";
f = fopen(path, "re");
if (!f)
return -errno;
return read_etc_hostname_stream(f, ret);
}
void hostname_update_source_hint(const char *hostname, HostnameSource source) {
int r;
/* Why save the value and not just create a flag file? This way we will
* notice if somebody sets the hostname directly (not going through hostnamed).
*/
if (source == HOSTNAME_DEFAULT) {
r = write_string_file("/run/systemd/default-hostname", hostname,
WRITE_STRING_FILE_CREATE | WRITE_STRING_FILE_ATOMIC);
if (r < 0)
log_warning_errno(r, "Failed to create \"/run/systemd/default-hostname\": %m");
} else
unlink_or_warn("/run/systemd/default-hostname");
}
int hostname_setup(bool really) {
_cleanup_free_ char *b = NULL;
const char *hn = NULL;
HostnameSource source;
bool enoent = false;
int r;
r = proc_cmdline_get_key("systemd.hostname", 0, &b);
if (r < 0)
log_warning_errno(r, "Failed to retrieve system hostname from kernel command line, ignoring: %m");
else if (r > 0) {
if (hostname_is_valid(b, VALID_HOSTNAME_TRAILING_DOT)) {
hn = b;
source = HOSTNAME_TRANSIENT;
} else {
log_warning("Hostname specified on kernel command line is invalid, ignoring: %s", b);
b = mfree(b);
}
}
if (!hn) {
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");
} else {
hn = b;
source = HOSTNAME_STATIC;
}
}
if (!hn) {
_cleanup_free_ char *buf = NULL;
/* Don't override the hostname if it is already set and not explicitly configured */
r = gethostname_full(GET_HOSTNAME_ALLOW_LOCALHOST, &buf);
if (r == -ENOMEM)
return log_oom();
if (r >= 0) {
log_debug("No hostname configured, leaving existing hostname <%s> in place.", buf);
return 0;
}
if (enoent)
log_info("No hostname configured, using default hostname.");
hn = b = get_default_hostname();
if (!hn)
return log_oom();
source = HOSTNAME_DEFAULT;
}
r = sethostname_idempotent_full(hn, really);
if (r < 0)
return log_warning_errno(r, "Failed to set hostname to <%s>: %m", hn);
if (r == 0)
log_debug("Hostname was already set to <%s>.", hn);
else
log_info("Hostname %s to <%s>.",
really ? "set" : "would have been set",
hn);
if (really)
hostname_update_source_hint(hn, source);
return r;
}
static const char* const hostname_source_table[] = {
[HOSTNAME_STATIC] = "static",
[HOSTNAME_TRANSIENT] = "transient",
[HOSTNAME_DEFAULT] = "default",
};
DEFINE_STRING_TABLE_LOOKUP(hostname_source, HostnameSource);
|
