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
|
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright 2015 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 <sys/utsname.h>
#include <ctype.h>
#include "util.h"
#include "hostname-util.h"
bool hostname_is_set(void) {
struct utsname u;
assert_se(uname(&u) >= 0);
if (isempty(u.nodename))
return false;
/* This is the built-in kernel default host name */
if (streq(u.nodename, "(none)"))
return false;
return true;
}
char* gethostname_malloc(void) {
struct utsname u;
assert_se(uname(&u) >= 0);
if (isempty(u.nodename) || streq(u.nodename, "(none)"))
return strdup(u.sysname);
return strdup(u.nodename);
}
static bool hostname_valid_char(char c) {
return
(c >= 'a' && c <= 'z') ||
(c >= 'A' && c <= 'Z') ||
(c >= '0' && c <= '9') ||
c == '-' ||
c == '_' ||
c == '.';
}
bool hostname_is_valid(const char *s) {
const char *p;
bool dot;
if (isempty(s))
return false;
/* Doesn't accept empty hostnames, hostnames with trailing or
* leading dots, and hostnames with multiple dots in a
* sequence. Also ensures that the length stays below
* HOST_NAME_MAX. */
for (p = s, dot = true; *p; p++) {
if (*p == '.') {
if (dot)
return false;
dot = true;
} else {
if (!hostname_valid_char(*p))
return false;
dot = false;
}
}
if (dot)
return false;
if (p-s > HOST_NAME_MAX)
return false;
return true;
}
char* hostname_cleanup(char *s, bool lowercase) {
char *p, *d;
bool dot;
assert(s);
for (p = s, d = s, dot = true; *p; p++) {
if (*p == '.') {
if (dot)
continue;
*(d++) = '.';
dot = true;
} else if (hostname_valid_char(*p)) {
*(d++) = lowercase ? tolower(*p) : *p;
dot = false;
}
}
if (dot && d > s)
d[-1] = 0;
else
*d = 0;
strshorten(s, HOST_NAME_MAX);
return s;
}
bool is_localhost(const char *hostname) {
assert(hostname);
/* This tries to identify local host and domain names
* described in RFC6761 plus the redhatism of .localdomain */
return streq(hostname, "localhost") ||
streq(hostname, "localhost.") ||
streq(hostname, "localdomain.") ||
streq(hostname, "localdomain") ||
endswith(hostname, ".localhost") ||
endswith(hostname, ".localhost.") ||
endswith(hostname, ".localdomain") ||
endswith(hostname, ".localdomain.");
}
int sethostname_idempotent(const char *s) {
char buf[HOST_NAME_MAX + 1] = {};
assert(s);
if (gethostname(buf, sizeof(buf)) < 0)
return -errno;
if (streq(buf, s))
return 0;
if (sethostname(s, strlen(s)) < 0)
return -errno;
return 1;
}
|
