X-Git-Url: https://git.arvados.org/arvados.git/blobdiff_plain/0df7a1c38affbc50a9c7d8834f9822e398860d91..3ac9fd0c91fe202a59e7c3611156bb1a9b8118fe:/services/api/app/models/arvados_model.rb

diff --git a/services/api/app/models/arvados_model.rb b/services/api/app/models/arvados_model.rb
index 1dcd9e2e82..154929171f 100644
--- a/services/api/app/models/arvados_model.rb
+++ b/services/api/app/models/arvados_model.rb
@@ -9,8 +9,10 @@ class ArvadosModel < ActiveRecord::Base
   attr_protected :modified_by_client_uuid
   attr_protected :modified_at
   after_initialize :log_start_state
-  before_create :ensure_permission_to_create
-  before_update :ensure_permission_to_update
+  before_save :ensure_permission_to_save
+  before_save :ensure_owner_uuid_is_permitted
+  before_save :ensure_ownership_path_leads_to_user
+  before_destroy :ensure_owner_uuid_is_permitted
   before_destroy :ensure_permission_to_destroy
 
   before_create :update_modified_by_fields
@@ -22,6 +24,9 @@ class ArvadosModel < ActiveRecord::Base
   validate :normalize_collection_uuids
   validate :ensure_valid_uuids
 
+  # Note: This only returns permission links. It does not account for
+  # permissions obtained via user.is_admin or
+  # user.uuid==object.owner_uuid.
   has_many :permissions, :foreign_key => :head_uuid, :class_name => 'Link', :primary_key => :uuid, :conditions => "link_class = 'permission'"
 
   class PermissionDeniedError < StandardError
@@ -87,9 +92,11 @@ class ArvadosModel < ActiveRecord::Base
       # A permission link exists ('write' and 'manage' implicitly include
       # 'read') from a member of users_list, or a group readable by users_list,
       # to this row, or to the owner of this row (see join() below).
+      permitted_uuids = "(SELECT head_uuid FROM links WHERE link_class='permission' AND tail_uuid IN (#{sanitized_uuid_list}))"
+
       sql_conds += ["#{table_name}.owner_uuid in (?)",
                     "#{table_name}.uuid in (?)",
-                    "permissions.head_uuid IS NOT NULL"]
+                    "#{table_name}.uuid IN #{permitted_uuids}"]
       sql_params += [uuid_list, user_uuids]
 
       if self == Link and users_list.any?
@@ -102,7 +109,7 @@ class ArvadosModel < ActiveRecord::Base
 
       if self == Log and users_list.any?
         # Link head points to the object described by this row
-        or_object_uuid = ", #{table_name}.object_uuid"
+        sql_conds += ["#{table_name}.object_uuid IN #{permitted_uuids}"]
 
         # This object described by this row is owned by this user, or owned by a group readable by this user
         sql_conds += ["#{table_name}.object_owner_uuid in (?)"]
@@ -115,15 +122,11 @@ class ArvadosModel < ActiveRecord::Base
       # user (the identity with authorization to read)
       #
       # Link class is 'permission' ('write' and 'manage' implicitly include 'read')
-
-      joins("LEFT JOIN links permissions ON permissions.head_uuid in (#{table_name}.owner_uuid, #{table_name}.uuid #{or_object_uuid}) AND permissions.tail_uuid in (#{sanitized_uuid_list}) AND permissions.link_class='permission'")
-        .where(sql_conds.join(' OR '), *sql_params).uniq
-
+      where(sql_conds.join(' OR '), *sql_params)
     else
       # At least one user is admin, so don't bother to apply any restrictions.
       self
     end
-
   end
 
   def logged_attributes
@@ -132,16 +135,71 @@ class ArvadosModel < ActiveRecord::Base
 
   protected
 
-  def ensure_permission_to_create
-    raise PermissionDeniedError unless permission_to_create
+  def ensure_ownership_path_leads_to_user
+    if new_record? or owner_uuid_changed?
+      uuid_in_path = {owner_uuid => true, uuid => true}
+      x = owner_uuid
+      while (owner_class = self.class.resource_class_for_uuid(x)) != User
+        begin
+          if x == uuid
+            # Test for cycles with the new version, not the DB contents
+            x = owner_uuid
+          elsif !owner_class.respond_to? :find_by_uuid
+            raise ActiveRecord::RecordNotFound.new
+          else
+            x = owner_class.find_by_uuid(x).owner_uuid
+          end
+        rescue ActiveRecord::RecordNotFound => e
+          errors.add :owner_uuid, "is not owned by any user: #{e}"
+          return false
+        end
+        if uuid_in_path[x]
+          if x == owner_uuid
+            errors.add :owner_uuid, "would create an ownership cycle"
+          else
+            errors.add :owner_uuid, "has an ownership cycle"
+          end
+          return false
+        end
+        uuid_in_path[x] = true
+      end
+    end
+    true
   end
 
-  def permission_to_create
-    current_user.andand.is_active
+  def ensure_owner_uuid_is_permitted
+    raise PermissionDeniedError if !current_user
+    self.owner_uuid ||= current_user.uuid
+    if self.owner_uuid_changed?
+      if current_user.uuid == self.owner_uuid or
+          current_user.can? write: self.owner_uuid
+        # current_user is, or has :write permission on, the new owner
+      else
+        logger.warn "User #{current_user.uuid} tried to change owner_uuid of #{self.class.to_s} #{self.uuid} to #{self.owner_uuid} but does not have permission to write to #{self.owner_uuid}"
+        raise PermissionDeniedError
+      end
+    end
+    if new_record?
+      return true
+    elsif current_user.uuid == self.owner_uuid_was or
+        current_user.uuid == self.uuid or
+        current_user.can? write: self.owner_uuid_was
+      # current user is, or has :write permission on, the previous owner
+      return true
+    else
+      logger.warn "User #{current_user.uuid} tried to modify #{self.class.to_s} #{self.uuid} but does not have permission to write #{self.owner_uuid_was}"
+      raise PermissionDeniedError
+    end
   end
 
-  def ensure_permission_to_update
-    raise PermissionDeniedError unless permission_to_update
+  def ensure_permission_to_save
+    unless (new_record? ? permission_to_create : permission_to_update)
+      raise PermissionDeniedError
+    end
+  end
+
+  def permission_to_create
+    current_user.andand.is_active
   end
 
   def permission_to_update
@@ -158,24 +216,7 @@ class ArvadosModel < ActiveRecord::Base
       logger.warn "User #{current_user.uuid} tried to change uuid of #{self.class.to_s} #{self.uuid_was} to #{self.uuid}"
       return false
     end
-    if self.owner_uuid_changed?
-      if current_user.uuid == self.owner_uuid or
-          current_user.can? write: self.owner_uuid
-        # current_user is, or has :write permission on, the new owner
-      else
-        logger.warn "User #{current_user.uuid} tried to change owner_uuid of #{self.class.to_s} #{self.uuid} to #{self.owner_uuid} but does not have permission to write to #{self.owner_uuid}"
-        return false
-      end
-    end
-    if current_user.uuid == self.owner_uuid_was or
-        current_user.uuid == self.uuid or
-        current_user.can? write: self.owner_uuid_was
-      # current user is, or has :write permission on, the previous owner
-      return true
-    else
-      logger.warn "User #{current_user.uuid} tried to modify #{self.class.to_s} #{self.uuid} but does not have permission to write #{self.owner_uuid_was}"
-      return false
-    end
+    return true
   end
 
   def ensure_permission_to_destroy