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-rw-r--r--src/core/ima-setup.c92
1 files changed, 92 insertions, 0 deletions
diff --git a/src/core/ima-setup.c b/src/core/ima-setup.c
new file mode 100644
index 0000000..7f517a0
--- /dev/null
+++ b/src/core/ima-setup.c
@@ -0,0 +1,92 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/***
+ Copyright © 2012 Roberto Sassu - Politecnico di Torino, Italy
+ TORSEC group — http://security.polito.it
+***/
+
+#include <errno.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "alloc-util.h"
+#include "fd-util.h"
+#include "fileio.h"
+#include "ima-setup.h"
+#include "log.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) {
+#if ENABLE_IMA
+ _cleanup_fclose_ FILE *input = NULL;
+ _cleanup_close_ int imafd = -1;
+ unsigned lineno = 0;
+ int r;
+
+ if (access(IMA_SECFS_DIR, F_OK) < 0) {
+ log_debug_errno(errno, "IMA support is disabled in the kernel, ignoring: %m");
+ return 0;
+ }
+
+ if (access(IMA_SECFS_POLICY, W_OK) < 0) {
+ log_warning_errno(errno, "Another IMA custom policy has already been loaded, ignoring: %m");
+ return 0;
+ }
+
+ if (access(IMA_POLICY_PATH, F_OK) < 0) {
+ log_debug_errno(errno, "No IMA custom policy file "IMA_POLICY_PATH", ignoring: %m");
+ 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_warning_errno(errno, "Failed to open the IMA custom policy file "IMA_POLICY_PATH", ignoring: %m");
+ return 0;
+ }
+
+ safe_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;
+ }
+
+ for (;;) {
+ _cleanup_free_ char *line = NULL;
+ size_t len;
+
+ r = read_line(input, LONG_LINE_MAX, &line);
+ if (r < 0)
+ return log_error_errno(r, "Failed to read the IMA custom policy file "IMA_POLICY_PATH": %m");
+ if (r == 0)
+ break;
+
+ 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 /* ENABLE_IMA */
+ return 0;
+}