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..37916bb
--- /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 = -EBADF;
+        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;
+}