X-Git-Url: https://git.arvados.org/arvados.git/blobdiff_plain/43c411ec1441ee1710dc33389d7451f7414a170f..b612ef0640ea45f03ad43ed4b124be1034d21071:/services/api/app/models/link.rb

diff --git a/services/api/app/models/link.rb b/services/api/app/models/link.rb
index b685bb6d75..21d89767c7 100644
--- a/services/api/app/models/link.rb
+++ b/services/api/app/models/link.rb
@@ -1,32 +1,44 @@
+# Copyright (C) The Arvados Authors. All rights reserved.
+#
+# SPDX-License-Identifier: AGPL-3.0
+
 class Link < ArvadosModel
-  include AssignUuid
+  include HasUuid
   include KindAndEtag
   include CommonApiTemplate
-  serialize :properties, Hash
+
+  # Posgresql JSONB columns should NOT be declared as serialized, Rails 5
+  # already know how to properly treat them.
+  attribute :properties, :jsonbHash, default: {}
+
+  validate :name_links_are_obsolete
   before_create :permission_to_attach_to_objects
   before_update :permission_to_attach_to_objects
-  after_update :maybe_invalidate_permissions_cache
-  after_create :maybe_invalidate_permissions_cache
-  after_destroy :maybe_invalidate_permissions_cache
-
-  attr_accessor :head
-  attr_accessor :tail
+  after_update :call_update_permissions
+  after_create :call_update_permissions
+  before_destroy :clear_permissions
+  after_destroy :check_permissions
 
-  api_accessible :superuser, :extend => :common do |t|
-    t.add :tail_kind
+  api_accessible :user, extend: :common do |t|
     t.add :tail_uuid
     t.add :link_class
     t.add :name
-    t.add :head_kind
     t.add :head_uuid
-    t.add :head, :if => :head
-    t.add :tail, :if => :tail
+    t.add :head_kind
+    t.add :tail_kind
     t.add :properties
   end
 
-  def properties
-    @properties ||= Hash.new
-    super
+  def head_kind
+    if k = ArvadosModel::resource_class_for_uuid(head_uuid)
+      k.kind
+    end
+  end
+
+  def tail_kind
+    if k = ArvadosModel::resource_class_for_uuid(tail_uuid)
+      k.kind
+    end
   end
 
   protected
@@ -41,36 +53,67 @@ class Link < ArvadosModel
     # Administrators can grant permissions
     return true if current_user.is_admin
 
-    # All users can grant permissions on objects they own
-    head_obj = self.class.
-      kind_class(self.head_kind).
-      where('uuid=?',head_uuid).
-      first
-    if head_obj
-      return true if head_obj.owner == current_user.uuid
-    end
+    head_obj = ArvadosModel.find_by_uuid(head_uuid)
+
+    # No permission links can be pointed to past collection versions
+    return false if head_obj.is_a?(Collection) && head_obj.current_version_uuid != head_uuid
 
-    # Users with "can_grant" permission on an object can grant
-    # permissions on that object
-    has_grant_permission = self.class.
-      where('link_class=? AND name=? AND tail_uuid=? AND head_uuid=?',
-            'permission', 'can_grant', current_user.uuid, self.head_uuid).
-      count > 0
-    return true if has_grant_permission
+    # All users can grant permissions on objects they own or can manage
+    return true if current_user.can?(manage: head_obj)
 
     # Default = deny.
     false
   end
 
-  def maybe_invalidate_permissions_cache
+  PERM_LEVEL = {
+    'can_read' => 1,
+    'can_login' => 1,
+    'can_write' => 2,
+    'can_manage' => 3,
+  }
+
+  def call_update_permissions
     if self.link_class == 'permission'
-      # Clearing the entire permissions cache can generate many
-      # unnecessary queries if many active users are not affected by
-      # this change. In such cases it would be better to search cached
-      # permissions for head_uuid and tail_uuid, and invalidate the
-      # cache for only those users. (This would require a browseable
-      # cache.)
-      User.invalidate_permissions_cache
+      update_permissions tail_uuid, head_uuid, PERM_LEVEL[name], self.uuid
+    end
+  end
+
+  def clear_permissions
+    if self.link_class == 'permission'
+      update_permissions tail_uuid, head_uuid, REVOKE_PERM, self.uuid
+    end
+  end
+
+  def check_permissions
+    if self.link_class == 'permission'
+      check_permissions_against_full_refresh
+    end
+  end
+
+  def name_links_are_obsolete
+    if link_class == 'name'
+      errors.add('name', 'Name links are obsolete')
+      false
+    else
+      true
+    end
+  end
+
+  # A user is permitted to create, update or modify a permission link
+  # if and only if they have "manage" permission on the object
+  # indicated by the permission link's head_uuid.
+  #
+  # All other links are treated as regular ArvadosModel objects.
+  #
+  def ensure_owner_uuid_is_permitted
+    if link_class == 'permission'
+      ob = ArvadosModel.find_by_uuid(head_uuid)
+      raise PermissionDeniedError unless current_user.can?(manage: ob)
+      # All permission links should be owned by the system user.
+      self.owner_uuid = system_user_uuid
+      return true
+    else
+      super
     end
   end
 end