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
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
|
/*-*- 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 <errno.h>
#include <unistd.h>
#include <malloc.h>
#include <sys/socket.h>
#include <sys/un.h>
#include "label.h"
#include "util.h"
#include "path-util.h"
#ifdef HAVE_SELINUX
#include <stdbool.h>
#include <selinux/selinux.h>
#include <selinux/label.h>
static struct selabel_handle *label_hnd = NULL;
static int use_selinux_cached = -1;
bool use_selinux(void) {
if (use_selinux_cached < 0)
use_selinux_cached = is_selinux_enabled() > 0;
return use_selinux_cached;
}
#endif
int label_init(const char *prefix) {
int r = 0;
#ifdef HAVE_SELINUX
usec_t before_timestamp, after_timestamp;
struct mallinfo before_mallinfo, after_mallinfo;
if (!use_selinux())
return 0;
if (label_hnd)
return 0;
before_mallinfo = mallinfo();
before_timestamp = now(CLOCK_MONOTONIC);
if (prefix) {
struct selinux_opt options[] = {
{ .type = SELABEL_OPT_SUBSET, .value = prefix },
};
label_hnd = selabel_open(SELABEL_CTX_FILE, options, ELEMENTSOF(options));
} else
label_hnd = selabel_open(SELABEL_CTX_FILE, NULL, 0);
if (!label_hnd) {
log_full(security_getenforce() == 1 ? LOG_ERR : LOG_DEBUG,
"Failed to initialize SELinux context: %m");
r = security_getenforce() == 1 ? -errno : 0;
} else {
char timespan[FORMAT_TIMESPAN_MAX];
int l;
after_timestamp = now(CLOCK_MONOTONIC);
after_mallinfo = mallinfo();
l = after_mallinfo.uordblks > before_mallinfo.uordblks ? after_mallinfo.uordblks - before_mallinfo.uordblks : 0;
log_debug("Successfully loaded SELinux database in %s, size on heap is %iK.",
format_timespan(timespan, sizeof(timespan), after_timestamp - before_timestamp, 0),
(l+1023)/1024);
}
#endif
return r;
}
int label_fix(const char *path, bool ignore_enoent, bool ignore_erofs) {
int r = 0;
#ifdef HAVE_SELINUX
struct stat st;
security_context_t fcon;
if (!use_selinux() || !label_hnd)
return 0;
r = lstat(path, &st);
if (r == 0) {
r = selabel_lookup_raw(label_hnd, &fcon, path, st.st_mode);
/* If there's no label to set, then exit without warning */
if (r < 0 && errno == ENOENT)
return 0;
if (r == 0) {
r = lsetfilecon(path, fcon);
freecon(fcon);
/* If the FS doesn't support labels, then exit without warning */
if (r < 0 && errno == ENOTSUP)
return 0;
}
}
if (r < 0) {
/* Ignore ENOENT in some cases */
if (ignore_enoent && errno == ENOENT)
return 0;
if (ignore_erofs && errno == EROFS)
return 0;
log_full(security_getenforce() == 1 ? LOG_ERR : LOG_DEBUG,
"Unable to fix label of %s: %m", path);
r = security_getenforce() == 1 ? -errno : 0;
}
#endif
return r;
}
void label_finish(void) {
#ifdef HAVE_SELINUX
if (use_selinux() && label_hnd)
selabel_close(label_hnd);
#endif
}
int label_context_set(const char *path, mode_t mode) {
int r = 0;
#ifdef HAVE_SELINUX
security_context_t filecon = NULL;
if (!use_selinux() || !label_hnd)
return 0;
r = selabel_lookup_raw(label_hnd, &filecon, path, mode);
if (r < 0 && errno != ENOENT)
r = -errno;
else if (r == 0) {
r = setfscreatecon(filecon);
if (r < 0) {
log_error("Failed to set SELinux file context on %s: %m", path);
r = -errno;
}
freecon(filecon);
}
if (r < 0 && security_getenforce() == 0)
r = 0;
#endif
return r;
}
void label_context_clear(void) {
#ifdef HAVE_SELINUX
if (!use_selinux())
return;
setfscreatecon(NULL);
#endif
}
int label_mkdir(const char *path, mode_t mode, bool apply) {
/* Creates a directory and labels it according to the SELinux policy */
#ifdef HAVE_SELINUX
int r;
security_context_t fcon = NULL;
if (!apply || !use_selinux() || !label_hnd)
goto skipped;
if (path_is_absolute(path))
r = selabel_lookup_raw(label_hnd, &fcon, path, S_IFDIR);
else {
char *newpath;
newpath = path_make_absolute_cwd(path);
if (!newpath)
return -ENOMEM;
r = selabel_lookup_raw(label_hnd, &fcon, newpath, S_IFDIR);
free(newpath);
}
if (r == 0)
r = setfscreatecon(fcon);
if (r < 0 && errno != ENOENT) {
log_error("Failed to set security context %s for %s: %m", fcon, path);
if (security_getenforce() == 1) {
r = -errno;
goto finish;
}
}
r = mkdir(path, mode);
if (r < 0)
r = -errno;
finish:
setfscreatecon(NULL);
freecon(fcon);
return r;
skipped:
#endif
return mkdir(path, mode) < 0 ? -errno : 0;
}
int label_apply(const char *path, const char *label) {
int r = 0;
#ifdef HAVE_SELINUX
if (!use_selinux())
return 0;
r = setfilecon(path, (char *)label);
#endif
return r;
}
|
