build-sys: use #if Y instead of #ifdef Y everywhere

[thirdparty/systemd.git] / src / core / ima-setup.c

diff --git a/src/core/ima-setup.c b/src/core/ima-setup.c
index 4d8b6381154498403c1bba6a4295b2a8bb1ba7e2..1aaae9f49ea6b9ed05c5e88965a50fcd8cf83ad4 100644 (file)
--- a/src/core/ima-setup.c
+++ b/src/core/ima-setup.c
@@ -1,11 +1,9 @@
-/*-*- 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
+                                     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
@@ -21,65 +19,80 @@
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
-#include <unistd.h>
 #include <errno.h>
-#include <fcntl.h>
-#include <sys/stat.h>
-#include <sys/mman.h>
+#include <unistd.h>
 
+#include "fd-util.h"
+#include "fileio.h"
 #include "ima-setup.h"
-#include "util.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) {
-        int r = 0;
-
-#ifdef HAVE_IMA
-        _cleanup_close_ int policyfd = -1, imafd = -1;
-        struct stat st;
-        char *policy;
+#if 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;
         }
 
-        policyfd = open(IMA_POLICY_PATH, O_RDONLY|O_CLOEXEC);
-        if (policyfd < 0) {
-                log_full_errno(errno == ENOENT ? LOG_DEBUG : LOG_WARNING, errno,
-                               "Failed to open the IMA custom policy file "IMA_POLICY_PATH", ignoring: %m");
+        if (access(IMA_SECFS_POLICY, W_OK) < 0) {
+                log_warning("Another IMA custom policy has already been loaded, ignoring.");
                 return 0;
         }
 
-        if (access(IMA_SECFS_POLICY, F_OK) < 0) {
-                log_warning("Another IMA custom policy has already been loaded, ignoring.");
+        if (access(IMA_POLICY_PATH, F_OK) < 0) {
+                log_debug("No IMA custom policy file "IMA_POLICY_PATH", 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_warning_errno(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;
         }
 
-        if (fstat(policyfd, &st) < 0)
-                return log_error_errno(errno, "Failed to fstat "IMA_POLICY_PATH": %m");
+        FOREACH_LINE(line, input,
+                     return log_error_errno(errno, "Failed to read the IMA custom policy file "IMA_POLICY_PATH": %m")) {
+                size_t len;
 
-        policy = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, policyfd, 0);
-        if (policy == MAP_FAILED)
-                return log_error_errno(errno, "Failed to mmap "IMA_POLICY_PATH": %m");
+                len = strlen(line);
+                lineno++;
 
-        r = loop_write(imafd, policy, (size_t) st.st_size, false);
-        if (r < 0)
-                log_error_errno(r, "Failed to load the IMA custom policy file "IMA_POLICY_PATH": %m");
-        else
-                log_info("Successfully loaded the IMA custom policy "IMA_POLICY_PATH".");
+                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);
+        }
 
-        munmap(policy, st.st_size);
+done:
+        log_info("Successfully loaded the IMA custom policy "IMA_POLICY_PATH".");
 #endif /* HAVE_IMA */
-        return r;
+        return 0;
 }