smack-util.c revision ad118bda159d3f9c27c5a15ace54cf808a6e8788
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright 2013 Intel Corporation
Author: Auke Kok <auke-jan.h.kok@intel.com>
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/xattr.h>
#include "util.h"
#include "process-util.h"
#include "path-util.h"
#include "fileio.h"
#include "smack-util.h"
#define SMACK_FLOOR_LABEL "_"
#define SMACK_STAR_LABEL "*"
bool mac_smack_use(void) {
#ifdef HAVE_SMACK
static int cached_use = -1;
if (cached_use < 0)
cached_use = access("/sys/fs/smackfs/", F_OK) >= 0;
return cached_use;
#else
return false;
#endif
}
int mac_smack_apply(const char *path, const char *label) {
int r = 0;
assert(path);
#ifdef HAVE_SMACK
if (!mac_smack_use())
return 0;
if (label)
r = lsetxattr(path, "security.SMACK64", label, strlen(label), 0);
else
r = lremovexattr(path, "security.SMACK64");
if (r < 0)
return -errno;
#endif
return r;
}
int mac_smack_apply_fd(int fd, const char *label) {
int r = 0;
assert(fd >= 0);
#ifdef HAVE_SMACK
if (!mac_smack_use())
return 0;
if (label)
r = fsetxattr(fd, "security.SMACK64", label, strlen(label), 0);
else
r = fremovexattr(fd, "security.SMACK64");
if (r < 0)
return -errno;
#endif
return r;
}
int mac_smack_apply_ip_out_fd(int fd, const char *label) {
int r = 0;
assert(fd >= 0);
#ifdef HAVE_SMACK
if (!mac_smack_use())
return 0;
if (label)
r = fsetxattr(fd, "security.SMACK64IPOUT", label, strlen(label), 0);
else
r = fremovexattr(fd, "security.SMACK64IPOUT");
if (r < 0)
return -errno;
#endif
return r;
}
int mac_smack_apply_ip_in_fd(int fd, const char *label) {
int r = 0;
assert(fd >= 0);
#ifdef HAVE_SMACK
if (!mac_smack_use())
return 0;
if (label)
r = fsetxattr(fd, "security.SMACK64IPIN", label, strlen(label), 0);
else
r = fremovexattr(fd, "security.SMACK64IPIN");
if (r < 0)
return -errno;
#endif
return r;
}
int mac_smack_apply_pid(pid_t pid, const char *label) {
#ifdef HAVE_SMACK
const char *p;
#endif
int r = 0;
assert(label);
#ifdef HAVE_SMACK
if (!mac_smack_use())
return 0;
p = procfs_file_alloca(pid, "attr/current");
r = write_string_file(p, label, 0);
if (r < 0)
return r;
#endif
return r;
}
int mac_smack_fix(const char *path, bool ignore_enoent, bool ignore_erofs) {
#ifdef HAVE_SMACK
struct stat st;
#endif
int r = 0;
assert(path);
#ifdef HAVE_SMACK
if (!mac_smack_use())
return 0;
/*
* Path must be in /dev and must exist
*/
if (!path_startswith(path, "/dev"))
return 0;
r = lstat(path, &st);
if (r >= 0) {
const char *label;
/*
* Label directories and character devices "*".
* Label symlinks "_".
* Don't change anything else.
*/
if (S_ISDIR(st.st_mode))
label = SMACK_STAR_LABEL;
else if (S_ISLNK(st.st_mode))
label = SMACK_FLOOR_LABEL;
else if (S_ISCHR(st.st_mode))
label = SMACK_STAR_LABEL;
else
return 0;
r = lsetxattr(path, "security.SMACK64", label, strlen(label), 0);
/* If the FS doesn't support labels, then exit without warning */
if (r < 0 && errno == EOPNOTSUPP)
return 0;
}
if (r < 0) {
/* Ignore ENOENT in some cases */
if (ignore_enoent && errno == ENOENT)
return 0;
if (ignore_erofs && errno == EROFS)
return 0;
r = log_debug_errno(errno, "Unable to fix SMACK label of %s: %m", path);
}
#endif
return r;
}