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/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright 2010 Lennart Poettering
Copyright (C) 2012 Roberto Sassu - Politecnico di Torino, Italy
TORSEC group -- http://security.polito.it
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 <unistd.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <stdlib.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include "ima-setup.h"
#include "mount-setup.h"
#include "macro.h"
#include "util.h"
#include "log.h"
#include "label.h"
#define IMA_SECFS_DIR "/sys/kernel/security/ima"
#define IMA_SECFS_POLICY IMA_SECFS_DIR "/policy"
#define IMA_POLICY_PATH "/etc/ima/ima-policy"
int ima_setup(void) {
int r = 0;
#ifdef HAVE_IMA
struct stat st;
ssize_t policy_size = 0;
char *policy;
_cleanup_close_ int policyfd = -1, imafd = -1;
if (stat(IMA_POLICY_PATH, &st) < 0)
return 0;
policy_size = st.st_size;
if (stat(IMA_SECFS_DIR, &st) < 0) {
log_debug("IMA support is disabled in the kernel, ignoring.");
return 0;
}
if (stat(IMA_SECFS_POLICY, &st) < 0) {
log_error("Another IMA custom policy has already been loaded, ignoring.");
return 0;
}
policyfd = open(IMA_POLICY_PATH, O_RDONLY|O_CLOEXEC);
if (policyfd < 0) {
log_error_errno(errno, "Failed to open the IMA custom policy file %s (%m), ignoring.",
IMA_POLICY_PATH);
return 0;
}
imafd = open(IMA_SECFS_POLICY, O_WRONLY|O_CLOEXEC);
if (imafd < 0) {
log_error_errno(errno, "Failed to open the IMA kernel interface %s (%m), ignoring.",
IMA_SECFS_POLICY);
goto out;
}
policy = mmap(NULL, policy_size, PROT_READ, MAP_PRIVATE, policyfd, 0);
if (policy == MAP_FAILED) {
log_error_errno(errno, "mmap() failed (%m), freezing");
r = -errno;
goto out;
}
r = loop_write(imafd, policy, (size_t)policy_size, false);
if (r < 0) {
log_error_errno(r, "Failed to load the IMA custom policy file %s (%m), ignoring.",
IMA_POLICY_PATH);
goto out_mmap;
}
log_info("Successfully loaded the IMA custom policy %s.",
IMA_POLICY_PATH);
out_mmap:
munmap(policy, policy_size);
out:
#endif /* HAVE_IMA */
return r;
}
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