mount: add new SmackFileSystemRoot= setting for mount unit

This option specifies the label to assign the root of the file system if
it lacks the Smack extended attribute. Note that this option will be
ignored if kernel does not support the Smack feature by runtime
checking.

1 files changed, 32 insertions, 4 deletions

diff --git a/src/core/mount.c b/src/core/mount.c
index 8611129453..0d1a9b9de7 100644
--- a/src/core/mount.c
+++ b/src/core/mount.c
@@ -39,6 +39,7 @@
 #include "exit-status.h"
 #include "fstab-util.h"
 #include "formats-util.h"
+#include "smack-util.h"
 
 #define RETRY_UMOUNT_MAX 32
 
@@ -202,6 +203,7 @@ static void mount_done(Unit *u) {
         assert(m);
 
         m->where = mfree(m->where);
+        m->smack_fs_root = mfree(m->smack_fs_root);
 
         mount_parameters_done(&m->parameters_proc_self_mountinfo);
         mount_parameters_done(&m->parameters_fragment);
@@ -666,7 +668,8 @@ static void mount_dump(Unit *u, FILE *f, const char *prefix) {
                 "%sOptions: %s\n"
                 "%sFrom /proc/self/mountinfo: %s\n"
                 "%sFrom fragment: %s\n"
-                "%sDirectoryMode: %04o\n",
+                "%sDirectoryMode: %04o\n"
+                "%sSmackFileSystemRoot: %s\n",
                 prefix, mount_state_to_string(m->state),
                 prefix, mount_result_to_string(m->result),
                 prefix, m->where,
@@ -675,7 +678,8 @@ static void mount_dump(Unit *u, FILE *f, const char *prefix) {
                 prefix, p ? strna(p->options) : "n/a",
                 prefix, yes_no(m->from_proc_self_mountinfo),
                 prefix, yes_no(m->from_fragment),
-                prefix, m->directory_mode);
+                prefix, m->directory_mode,
+                prefix, strna(m->smack_fs_root));
 
         if (m->control_pid > 0)
                 fprintf(f,
@@ -852,6 +856,31 @@ fail:
         mount_enter_mounted(m, MOUNT_FAILURE_RESOURCES);
 }
 
+static int mount_get_opts(Mount *m, char **_opts) {
+        int r;
+        char *o = NULL, *opts = NULL;
+
+        r = fstab_filter_options(m->parameters_fragment.options,
+                                 "nofail\0" "noauto\0" "auto\0", NULL, NULL, &o);
+        if (r < 0)
+                return r;
+
+        if (mac_smack_use() && m->smack_fs_root) {
+                if (!isempty(o)) {
+                        opts = strjoin(o, ",", "smackfsroot=", m->smack_fs_root, NULL);
+                        free(o);
+                } else
+                        opts = strjoin("smackfsroot=", m->smack_fs_root, NULL);
+
+                if (!opts)
+                        return -ENOMEM;
+        } else
+                opts = o;
+
+        *_opts = opts;
+        return 0;
+}
+
 static void mount_enter_mounting(Mount *m) {
         int r;
         MountParameters *p;
@@ -877,8 +906,7 @@ static void mount_enter_mounting(Mount *m) {
         if (m->from_fragment) {
                 _cleanup_free_ char *opts = NULL;
 
-                r = fstab_filter_options(m->parameters_fragment.options,
-                                         "nofail\0" "noauto\0" "auto\0", NULL, NULL, &opts);
+                r = mount_get_opts(m, &opts);
                 if (r < 0)
                         goto fail;