apparmor: allow introspecting the policy namespace name

Signed-off-by: NJohn Johansen <john.johansen@canonical.com>

security/apparmor/apparmorfs.c

@@ -356,6 +356,7 @@ static const struct file_operations aa_fs_seq_hash_fops = {
 	.release	= single_release,
 };
 
+
 static int aa_fs_seq_show_ns_level(struct seq_file *seq, void *v)
 {
 	struct aa_ns *ns = aa_current_profile()->ns;
@@ -378,6 +379,28 @@ static const struct file_operations aa_fs_ns_level = {
 	.release	= single_release,
 };
 
+static int aa_fs_seq_show_ns_name(struct seq_file *seq, void *v)
+{
+	struct aa_ns *ns = aa_current_profile()->ns;
+
+	seq_printf(seq, "%s\n", ns->base.name);
+
+	return 0;
+}
+
+static int aa_fs_seq_open_ns_name(struct inode *inode, struct file *file)
+{
+	return single_open(file, aa_fs_seq_show_ns_name, inode->i_private);
+}
+
+static const struct file_operations aa_fs_ns_name = {
+	.owner		= THIS_MODULE,
+	.open		= aa_fs_seq_open_ns_name,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
 /** fns to setup dynamic per profile/namespace files **/
 void __aa_fs_profile_rmdir(struct aa_profile *profile)
 {
@@ -852,6 +875,7 @@ static struct aa_fs_entry aa_fs_entry_apparmor[] = {
 	AA_FS_FILE_FOPS(".replace", 0640, &aa_fs_profile_replace),
 	AA_FS_FILE_FOPS(".remove", 0640, &aa_fs_profile_remove),
 	AA_FS_FILE_FOPS(".ns_level", 0666, &aa_fs_ns_level),
+	AA_FS_FILE_FOPS(".ns_name", 0640, &aa_fs_ns_name),
 	AA_FS_FILE_FOPS("profiles", 0640, &aa_fs_profiles_fops),
 	AA_FS_DIR("features", aa_fs_entry_features),
 	{ }