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/*-*- 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 <sys/stat.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;
}
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