1 files changed, 67 insertions, 0 deletions
diff --git a/app/helpers/lfs_helper.rb b/app/helpers/lfs_helper.rb
new file mode 100644
index 00000000000..eb651e3687e
--- /dev/null
+++ b/app/helpers/lfs_helper.rb
@@ -0,0 +1,67 @@
+module LfsHelper
+  def require_lfs_enabled!
+    return if Gitlab.config.lfs.enabled
+
+    render(
+      json: {
+        message: 'Git LFS is not enabled on this GitLab server, contact your admin.',
+        documentation_url: "#{Gitlab.config.gitlab.url}/help",
+      },
+      status: 501
+    )
+  end
+
+  def lfs_check_access!
+    return if download_request? && lfs_download_access?
+    return if upload_request? && lfs_upload_access?
+
+    if project.public? || (user && user.can?(:read_project, project))
+      render_lfs_forbidden
+    else
+      render_lfs_not_found
+    end
+  end
+
+  def lfs_download_access?
+    project.public? || ci? || (user && user.can?(:download_code, project))
+  end
+
+  def lfs_upload_access?
+    user && user.can?(:push_code, project)
+  end
+
+  def render_lfs_forbidden
+    render(
+      json: {
+        message: 'Access forbidden. Check your access level.',
+        documentation_url: "#{Gitlab.config.gitlab.url}/help",
+      },
+      content_type: "application/vnd.git-lfs+json",
+      status: 403
+    )
+  end
+
+  def render_lfs_not_found
+    render(
+      json: {
+        message: 'Not found.',
+        documentation_url: "#{Gitlab.config.gitlab.url}/help",
+      },
+      content_type: "application/vnd.git-lfs+json",
+      status: 404
+    )
+  end
+
+  def storage_project
+    @storage_project ||= begin
+      result = project
+
+      loop do
+        break unless result.forked?
+        result = result.forked_from_project
+      end
+
+      result
+    end
+  end
+end