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vmspawn: Run auxiliary daemons inside scope instead of separate service (#38047)
[thirdparty/systemd.git] / src / core / selinux-setup.c
1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
2
3 #include <unistd.h>
4
5 #include "sd-messages.h"
6
7 #include "errno-util.h"
8 #include "initrd-util.h"
9 #include "log.h"
10 #include "selinux-setup.h"
11 #include "selinux-util.h"
12 #include "string-util.h"
13 #include "time-util.h"
14
15 int mac_selinux_setup(bool *loaded_policy) {
16 assert(loaded_policy);
17
18 #if HAVE_SELINUX
19 int r;
20
21 mac_selinux_disable_logging();
22
23 /* Don't load policy in the initrd if we don't appear to have it. For the real root, we check below
24 * if we've already loaded policy, and return gracefully. */
25 if (in_initrd() && access(selinux_path(), F_OK) < 0) {
26 if (errno != ENOENT)
27 log_warning_errno(errno, "Unable to check if %s exists, assuming it does not: %m", selinux_path());
28
29 return 0;
30 }
31
32 bool initialized = false;
33
34 /* Already initialized by somebody else?
35 *
36 * Note: getcon_raw() can return 0, and still give us a NULL pointer if /proc/self/attr/current is
37 * empty. SELinux guarantees this won't happen, but that file isn't specific to SELinux, and may be
38 * provided by some other arbitrary LSM with different semantics. */
39 _cleanup_freecon_ char *con = NULL;
40 if (getcon_raw(&con) < 0)
41 log_debug_errno(errno, "getcon_raw() failed, assuming SELinux is not initialized: %m");
42 else if (con) {
43 initialized = !streq(con, "kernel");
44 log_debug("SELinux already initialized: %s", yes_no(initialized));
45 }
46
47 /* Make sure we have no fds open while loading the policy and transitioning */
48 log_close();
49
50 /* Now load the policy */
51 usec_t before_load = now(CLOCK_MONOTONIC);
52 int enforce = 0;
53 if (selinux_init_load_policy(&enforce) == 0) { /* NB: Apparently doesn't set useful errno! */
54 mac_selinux_retest();
55
56 /* Transition to the new context */
57 _cleanup_freecon_ char *label = NULL;
58 r = mac_selinux_get_create_label_from_exe(SYSTEMD_BINARY_PATH, &label);
59 if (r < 0) {
60 log_open();
61 log_warning_errno(r, "Failed to compute init label, ignoring: %m");
62 } else {
63 r = RET_NERRNO(setcon_raw(label));
64 log_open();
65 if (r < 0)
66 log_warning_errno(r, "Failed to transition into init label '%s', ignoring: %m", label);
67 else
68 log_debug("Successfully switched to calculated init label '%s'.", label);
69 }
70
71 usec_t after_load = now(CLOCK_MONOTONIC);
72 log_info("Successfully loaded SELinux policy in %s.",
73 FORMAT_TIMESPAN(after_load - before_load, 0));
74
75 *loaded_policy = true;
76 } else {
77 log_open();
78
79 if (enforce > 0) {
80 if (!initialized)
81 return log_struct_errno(LOG_EMERG, SYNTHETIC_ERRNO(EIO),
82 LOG_MESSAGE("Failed to load SELinux policy :%m"),
83 LOG_MESSAGE_ID(SD_MESSAGE_SELINUX_FAILED_STR));
84
85 log_notice("Failed to load new SELinux policy. Continuing with old policy.");
86 } else
87 log_debug("Unable to load SELinux policy. Ignoring.");
88 }
89 #endif
90
91 return 0;
92 }