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
|
/* SPDX-License-Identifier: LGPL-2.1-or-later */
#include <errno.h>
#include <stdio.h>
#include <unistd.h>
#if HAVE_SELINUX
#include <selinux/selinux.h>
#endif
#include "log.h"
#include "macro.h"
#include "selinux-setup.h"
#include "selinux-util.h"
#include "string-util.h"
#include "time-util.h"
#include "util.h"
#if HAVE_SELINUX
_printf_(2,3)
static int null_log(int type, const char *fmt, ...) {
return 0;
}
#endif
int mac_selinux_setup(bool *loaded_policy) {
#if HAVE_SELINUX
int enforce = 0;
usec_t before_load, after_load;
char *con;
int r;
bool initialized = false;
assert(loaded_policy);
/* Turn off all of SELinux' own logging, we want to do that */
selinux_set_callback(SELINUX_CB_LOG, (union selinux_callback) { .func_log = null_log });
/* Don't load policy in the initrd if we don't appear to have
* it. For the real root, we check below if we've already
* loaded policy, and return gracefully.
*/
if (in_initrd() && access(selinux_path(), F_OK) < 0)
return 0;
/* Already initialized by somebody else? */
r = getcon_raw(&con);
/* getcon_raw can return 0, and still give us a NULL pointer if
* /proc/self/attr/current is empty. SELinux guarantees this won't
* happen, but that file isn't specific to SELinux, and may be provided
* by some other arbitrary LSM with different semantics. */
if (r == 0 && con) {
initialized = !streq(con, "kernel");
freecon(con);
}
/* Make sure we have no fds open while loading the policy and
* transitioning */
log_close();
/* Now load the policy */
before_load = now(CLOCK_MONOTONIC);
r = selinux_init_load_policy(&enforce);
if (r == 0) {
_cleanup_(mac_selinux_freep) char *label = NULL;
mac_selinux_retest();
/* Transition to the new context */
r = mac_selinux_get_create_label_from_exe(SYSTEMD_BINARY_PATH, &label);
if (r < 0 || !label) {
log_open();
log_error("Failed to compute init label, ignoring.");
} else {
r = setcon_raw(label);
log_open();
if (r < 0)
log_error("Failed to transition into init label '%s', ignoring.", label);
}
after_load = now(CLOCK_MONOTONIC);
log_info("Successfully loaded SELinux policy in %s.",
FORMAT_TIMESPAN(after_load - before_load, 0));
*loaded_policy = true;
} else {
log_open();
if (enforce > 0) {
if (!initialized)
return log_emergency_errno(SYNTHETIC_ERRNO(EIO),
"Failed to load SELinux policy.");
log_warning("Failed to load new SELinux policy. Continuing with old policy.");
} else
log_debug("Unable to load SELinux policy. Ignoring.");
}
#endif
return 0;
}
|
