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/***
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 <errno.h>
#include <unistd.h>
#include "fd-util.h"
#include "fileio.h"
#include "ima-setup.h"
#include "log.h"
#include "util.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) {
#ifdef HAVE_IMA
_cleanup_fclose_ FILE *input = NULL;
_cleanup_close_ int imafd = -1;
unsigned lineno = 0;
char line[page_size()];
if (access(IMA_SECFS_DIR, F_OK) < 0) {
log_debug("IMA support is disabled in the kernel, ignoring.");
return 0;
}
if (access(IMA_SECFS_POLICY, W_OK) < 0) {
log_warning("Another IMA custom policy has already been loaded, ignoring.");
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 "IMA_SECFS_POLICY", ignoring: %m");
return 0;
}
/* attempt to write the name of the policy file into sysfs file */
if (write(imafd, IMA_POLICY_PATH, strlen(IMA_POLICY_PATH)) > 0)
goto done;
/* fall back to copying the policy line-by-line */
input = fopen(IMA_POLICY_PATH, "re");
if (!input) {
log_full_errno(errno == ENOENT ? LOG_DEBUG : LOG_WARNING, errno,
"Failed to open the IMA custom policy file "IMA_POLICY_PATH", ignoring: %m");
return 0;
}
close(imafd);
imafd = open(IMA_SECFS_POLICY, O_WRONLY|O_CLOEXEC);
if (imafd < 0) {
log_error_errno(errno, "Failed to open the IMA kernel interface "IMA_SECFS_POLICY", ignoring: %m");
return 0;
}
FOREACH_LINE(line, input,
return log_error_errno(errno, "Failed to read the IMA custom policy file "IMA_POLICY_PATH": %m")) {
size_t len;
len = strlen(line);
lineno++;
if (len > 0 && write(imafd, line, len) < 0)
return log_error_errno(errno, "Failed to load the IMA custom policy file "IMA_POLICY_PATH"%u: %m",
lineno);
}
done:
log_info("Successfully loaded the IMA custom policy "IMA_POLICY_PATH".");
#endif /* HAVE_IMA */
return 0;
}
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