AppArmor: refactor securityfs to use structures
Use a file tree structure to represent the AppArmor securityfs.
Signed-off-by: Kees Cook <kees@ubuntu.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
diff --git a/security/apparmor/apparmorfs.c b/security/apparmor/apparmorfs.c
index e39df6d..1e22bb3 100644
--- a/security/apparmor/apparmorfs.c
+++ b/security/apparmor/apparmorfs.c
@@ -144,36 +144,103 @@
/** Base file system setup **/
-static struct dentry *aa_fs_dentry __initdata;
+static struct aa_fs_entry aa_fs_entry_apparmor[] = {
+ AA_FS_FILE_FOPS(".load", 0640, &aa_fs_profile_load),
+ AA_FS_FILE_FOPS(".replace", 0640, &aa_fs_profile_replace),
+ AA_FS_FILE_FOPS(".remove", 0640, &aa_fs_profile_remove),
+ { }
+};
-static void __init aafs_remove(const char *name)
+static struct aa_fs_entry aa_fs_entry =
+ AA_FS_DIR("apparmor", aa_fs_entry_apparmor);
+
+/**
+ * aafs_create_file - create a file entry in the apparmor securityfs
+ * @fs_file: aa_fs_entry to build an entry for (NOT NULL)
+ * @parent: the parent dentry in the securityfs
+ *
+ * Use aafs_remove_file to remove entries created with this fn.
+ */
+static int __init aafs_create_file(struct aa_fs_entry *fs_file,
+ struct dentry *parent)
{
- struct dentry *dentry;
+ int error = 0;
- dentry = lookup_one_len(name, aa_fs_dentry, strlen(name));
- if (!IS_ERR(dentry)) {
- securityfs_remove(dentry);
- dput(dentry);
+ fs_file->dentry = securityfs_create_file(fs_file->name,
+ S_IFREG | fs_file->mode,
+ parent, fs_file,
+ fs_file->file_ops);
+ if (IS_ERR(fs_file->dentry)) {
+ error = PTR_ERR(fs_file->dentry);
+ fs_file->dentry = NULL;
}
+ return error;
}
/**
- * aafs_create - create an entry in the apparmor filesystem
- * @name: name of the entry (NOT NULL)
- * @mask: file permission mask of the file
- * @fops: file operations for the file (NOT NULL)
+ * aafs_create_dir - recursively create a directory entry in the securityfs
+ * @fs_dir: aa_fs_entry (and all child entries) to build (NOT NULL)
+ * @parent: the parent dentry in the securityfs
*
- * Used aafs_remove to remove entries created with this fn.
+ * Use aafs_remove_dir to remove entries created with this fn.
*/
-static int __init aafs_create(const char *name, umode_t mask,
- const struct file_operations *fops)
+static int __init aafs_create_dir(struct aa_fs_entry *fs_dir,
+ struct dentry *parent)
{
- struct dentry *dentry;
+ int error;
+ struct aa_fs_entry *fs_file;
- dentry = securityfs_create_file(name, S_IFREG | mask, aa_fs_dentry,
- NULL, fops);
+ fs_dir->dentry = securityfs_create_dir(fs_dir->name, parent);
+ if (IS_ERR(fs_dir->dentry)) {
+ error = PTR_ERR(fs_dir->dentry);
+ fs_dir->dentry = NULL;
+ goto failed;
+ }
- return IS_ERR(dentry) ? PTR_ERR(dentry) : 0;
+ for (fs_file = fs_dir->v.files; fs_file->name; ++fs_file) {
+ if (fs_file->v_type == AA_FS_TYPE_DIR)
+ error = aafs_create_dir(fs_file, fs_dir->dentry);
+ else
+ error = aafs_create_file(fs_file, fs_dir->dentry);
+ if (error)
+ goto failed;
+ }
+
+ return 0;
+
+failed:
+ return error;
+}
+
+/**
+ * aafs_remove_file - drop a single file entry in the apparmor securityfs
+ * @fs_file: aa_fs_entry to detach from the securityfs (NOT NULL)
+ */
+static void __init aafs_remove_file(struct aa_fs_entry *fs_file)
+{
+ if (!fs_file->dentry)
+ return;
+
+ securityfs_remove(fs_file->dentry);
+ fs_file->dentry = NULL;
+}
+
+/**
+ * aafs_remove_dir - recursively drop a directory entry from the securityfs
+ * @fs_dir: aa_fs_entry (and all child entries) to detach (NOT NULL)
+ */
+static void __init aafs_remove_dir(struct aa_fs_entry *fs_dir)
+{
+ struct aa_fs_entry *fs_file;
+
+ for (fs_file = fs_dir->v.files; fs_file->name; ++fs_file) {
+ if (fs_file->v_type == AA_FS_TYPE_DIR)
+ aafs_remove_dir(fs_file);
+ else
+ aafs_remove_file(fs_file);
+ }
+
+ aafs_remove_file(fs_dir);
}
/**
@@ -183,14 +250,7 @@
*/
void __init aa_destroy_aafs(void)
{
- if (aa_fs_dentry) {
- aafs_remove(".remove");
- aafs_remove(".replace");
- aafs_remove(".load");
-
- securityfs_remove(aa_fs_dentry);
- aa_fs_dentry = NULL;
- }
+ aafs_remove_dir(&aa_fs_entry);
}
/**
@@ -207,25 +267,13 @@
if (!apparmor_initialized)
return 0;
- if (aa_fs_dentry) {
+ if (aa_fs_entry.dentry) {
AA_ERROR("%s: AppArmor securityfs already exists\n", __func__);
return -EEXIST;
}
- aa_fs_dentry = securityfs_create_dir("apparmor", NULL);
- if (IS_ERR(aa_fs_dentry)) {
- error = PTR_ERR(aa_fs_dentry);
- aa_fs_dentry = NULL;
- goto error;
- }
-
- error = aafs_create(".load", 0640, &aa_fs_profile_load);
- if (error)
- goto error;
- error = aafs_create(".replace", 0640, &aa_fs_profile_replace);
- if (error)
- goto error;
- error = aafs_create(".remove", 0640, &aa_fs_profile_remove);
+ /* Populate fs tree. */
+ error = aafs_create_dir(&aa_fs_entry, NULL);
if (error)
goto error;
diff --git a/security/apparmor/include/apparmorfs.h b/security/apparmor/include/apparmorfs.h
index cb1e93a..4fdf02f 100644
--- a/security/apparmor/include/apparmorfs.h
+++ b/security/apparmor/include/apparmorfs.h
@@ -15,6 +15,30 @@
#ifndef __AA_APPARMORFS_H
#define __AA_APPARMORFS_H
+enum aa_fs_type {
+ AA_FS_TYPE_FOPS,
+ AA_FS_TYPE_DIR,
+};
+
+struct aa_fs_entry;
+
+struct aa_fs_entry {
+ const char *name;
+ struct dentry *dentry;
+ umode_t mode;
+ enum aa_fs_type v_type;
+ union {
+ struct aa_fs_entry *files;
+ } v;
+ const struct file_operations *file_ops;
+};
+
+#define AA_FS_FILE_FOPS(_name, _mode, _fops) \
+ { .name = (_name), .v_type = AA_FS_TYPE_FOPS, \
+ .mode = (_mode), .file_ops = (_fops) }
+#define AA_FS_DIR(_name, _value) \
+ { .name = (_name), .v_type = AA_FS_TYPE_DIR, .v.files = (_value) }
+
extern void __init aa_destroy_aafs(void);
#endif /* __AA_APPARMORFS_H */