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/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright (C) 2013 Intel Corporation
Authors:
Nathaniel Chen <nathaniel.chen@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 <stdio.h>
#include <errno.h>
#include <string.h>
#include <stdlib.h>
#include <fcntl.h>
#include <dirent.h>
#include "macro.h"
#include "smack-setup.h"
#include "util.h"
#include "fileio.h"
#include "log.h"
#ifdef HAVE_SMACK
static int write_access2_rules(const char* srcdir) {
_cleanup_close_ int load2_fd = -1, change_fd = -1;
_cleanup_closedir_ DIR *dir = NULL;
struct dirent *entry;
char buf[NAME_MAX];
int dfd = -1;
int r = 0;
load2_fd = open("/sys/fs/smackfs/load2", O_RDWR|O_CLOEXEC|O_NONBLOCK|O_NOCTTY);
if (load2_fd < 0) {
if (errno != ENOENT)
log_warning_errno(errno, "Failed to open '/sys/fs/smackfs/load2': %m");
return -errno; /* negative error */
}
change_fd = open("/sys/fs/smackfs/change-rule", O_RDWR|O_CLOEXEC|O_NONBLOCK|O_NOCTTY);
if (change_fd < 0) {
if (errno != ENOENT)
log_warning_errno(errno, "Failed to open '/sys/fs/smackfs/change-rule': %m");
return -errno; /* negative error */
}
/* write rules to load2 or change-rule from every file in the directory */
dir = opendir(srcdir);
if (!dir) {
if (errno != ENOENT)
log_warning_errno(errno, "Failed to opendir '%s': %m", srcdir);
return errno; /* positive on purpose */
}
dfd = dirfd(dir);
assert(dfd >= 0);
FOREACH_DIRENT(entry, dir, return 0) {
int fd;
_cleanup_fclose_ FILE *policy = NULL;
if (!dirent_is_file(entry))
continue;
fd = openat(dfd, entry->d_name, O_RDONLY|O_CLOEXEC);
if (fd < 0) {
if (r == 0)
r = -errno;
log_warning_errno(errno, "Failed to open '%s': %m", entry->d_name);
continue;
}
policy = fdopen(fd, "re");
if (!policy) {
if (r == 0)
r = -errno;
safe_close(fd);
log_error_errno(errno, "Failed to open '%s': %m", entry->d_name);
continue;
}
/* load2 write rules in the kernel require a line buffered stream */
FOREACH_LINE(buf, policy,
log_error_errno(errno, "Failed to read line from '%s': %m",
entry->d_name)) {
_cleanup_free_ char *sbj = NULL, *obj = NULL, *acc1 = NULL, *acc2 = NULL;
if (isempty(truncate_nl(buf)))
continue;
/* if 3 args -> load rule : subject object access1 */
/* if 4 args -> change rule : subject object access1 access2 */
if (sscanf(buf, "%ms %ms %ms %ms", &sbj, &obj, &acc1, &acc2) < 3) {
log_error_errno(errno, "Failed to parse rule '%s' in '%s', ignoring.", buf, entry->d_name);
continue;
}
if (write(isempty(acc2) ? load2_fd : change_fd, buf, strlen(buf)) < 0) {
if (r == 0)
r = -errno;
log_error_errno(errno, "Failed to write '%s' to '%s' in '%s'",
buf, isempty(acc2) ? "/sys/fs/smackfs/load2" : "/sys/fs/smackfs/change-rule", entry->d_name);
}
}
}
return r;
}
static int write_cipso2_rules(const char* srcdir) {
_cleanup_close_ int cipso2_fd = -1;
_cleanup_closedir_ DIR *dir = NULL;
struct dirent *entry;
char buf[NAME_MAX];
int dfd = -1;
int r = 0;
cipso2_fd = open("/sys/fs/smackfs/cipso2", O_RDWR|O_CLOEXEC|O_NONBLOCK|O_NOCTTY);
if (cipso2_fd < 0) {
if (errno != ENOENT)
log_warning_errno(errno, "Failed to open '/sys/fs/smackfs/cipso2': %m");
return -errno; /* negative error */
}
/* write rules to cipso2 from every file in the directory */
dir = opendir(srcdir);
if (!dir) {
if (errno != ENOENT)
log_warning_errno(errno, "Failed to opendir '%s': %m", srcdir);
return errno; /* positive on purpose */
}
dfd = dirfd(dir);
assert(dfd >= 0);
FOREACH_DIRENT(entry, dir, return 0) {
int fd;
_cleanup_fclose_ FILE *policy = NULL;
if (!dirent_is_file(entry))
continue;
fd = openat(dfd, entry->d_name, O_RDONLY|O_CLOEXEC);
if (fd < 0) {
if (r == 0)
r = -errno;
log_error_errno(errno, "Failed to open '%s': %m", entry->d_name);
continue;
}
policy = fdopen(fd, "re");
if (!policy) {
if (r == 0)
r = -errno;
safe_close(fd);
log_error_errno(errno, "Failed to open '%s': %m", entry->d_name);
continue;
}
/* cipso2 write rules in the kernel require a line buffered stream */
FOREACH_LINE(buf, policy,
log_error_errno(errno, "Failed to read line from '%s': %m",
entry->d_name)) {
if (isempty(truncate_nl(buf)))
continue;
if (write(cipso2_fd, buf, strlen(buf)) < 0) {
if (r == 0)
r = -errno;
log_error_errno(errno, "Failed to write '%s' to '/sys/fs/smackfs/cipso2' in '%s'",
buf, entry->d_name);
break;
}
}
}
return r;
}
#endif
int mac_smack_setup(bool *loaded_policy) {
#ifdef HAVE_SMACK
int r;
assert(loaded_policy);
r = write_access2_rules("/etc/smack/accesses.d/");
switch(r) {
case -ENOENT:
log_debug("Smack is not enabled in the kernel.");
return 0;
case ENOENT:
log_debug("Smack access rules directory '/etc/smack/accesses.d/' not found");
return 0;
case 0:
log_info("Successfully loaded Smack policies.");
break;
default:
log_warning("Failed to load Smack access rules: %s, ignoring.",
strerror(abs(r)));
return 0;
}
#ifdef SMACK_RUN_LABEL
r = write_string_file("/proc/self/attr/current", SMACK_RUN_LABEL, 0);
if (r)
log_warning("Failed to set SMACK label \"%s\" on self: %s",
SMACK_RUN_LABEL, strerror(-r));
#endif
r = write_cipso2_rules("/etc/smack/cipso.d/");
switch(r) {
case -ENOENT:
log_debug("Smack/CIPSO is not enabled in the kernel.");
return 0;
case ENOENT:
log_debug("Smack/CIPSO access rules directory '/etc/smack/cipso.d/' not found");
return 0;
case 0:
log_info("Successfully loaded Smack/CIPSO policies.");
break;
default:
log_warning("Failed to load Smack/CIPSO access rules: %s, ignoring.",
strerror(abs(r)));
return 0;
}
*loaded_policy = true;
#endif
return 0;
}
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