X-Git-Url: https://git.arvados.org/arvados.git/blobdiff_plain/cbf0429a8a5edd2f8a8d9b01ce39334e07e56bf8..35c20b4ad8220131f7f6bad6b3806a7d28df3ef3:/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 9dfca2d941..95fd055d49 100644
--- a/services/api/app/models/arvados_model.rb
+++ b/services/api/app/models/arvados_model.rb
@@ -1,4 +1,5 @@
-require 'assign_uuid'
+require 'has_uuid'
+
 class ArvadosModel < ActiveRecord::Base
   self.abstract_class = true
 
@@ -9,15 +10,17 @@ 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
   before_update :maybe_update_modified_by_fields
   after_create :log_create
   after_update :log_update
   after_destroy :log_destroy
+  after_find :convert_serialized_symbols_to_strings
   validate :ensure_serialized_attribute_type
   validate :normalize_collection_uuids
   validate :ensure_valid_uuids
@@ -62,6 +65,24 @@ class ArvadosModel < ActiveRecord::Base
     self.columns.select { |col| col.name == attr.to_s }.first
   end
 
+  # Return nil if current user is not allowed to see the list of
+  # writers. Otherwise, return a list of user_ and group_uuids with
+  # write permission. (If not returning nil, current_user is always in
+  # the list because can_manage permission is needed to see the list
+  # of writers.)
+  def writable_by
+    unless (owner_uuid == current_user.uuid or
+            current_user.is_admin or
+            current_user.groups_i_can(:manage).index(owner_uuid))
+      return nil
+    end
+    [owner_uuid, current_user.uuid] + permissions.collect do |p|
+      if ['can_write', 'can_manage'].index p.name
+        p.tail_uuid
+      end
+    end.compact.uniq
+  end
+
   # Return a query with read permissions restricted to the union of of the
   # permissions of the members of users_list, i.e. if something is readable by
   # any user in users_list, it will be readable in the query returned by this
@@ -90,9 +111,11 @@ 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?
@@ -105,7 +128,7 @@ 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 (?)"]
@@ -118,15 +141,11 @@ 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
@@ -135,16 +154,75 @@ 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
+    if respond_to? :owner_uuid=
+      self.owner_uuid ||= current_user.uuid
+    end
+    if self.owner_uuid_changed?
+      if new_record?
+        return true
+      elsif 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
@@ -161,24 +239,7 @@ 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
@@ -191,6 +252,7 @@ class ArvadosModel < ActiveRecord::Base
 
   def maybe_update_modified_by_fields
     update_modified_by_fields if self.changed? or self.new_record?
+    true
   end
 
   def update_modified_by_fields
@@ -199,6 +261,39 @@ class ArvadosModel < ActiveRecord::Base
     self.modified_at = Time.now
     self.modified_by_user_uuid = current_user ? current_user.uuid : nil
     self.modified_by_client_uuid = current_api_client ? current_api_client.uuid : nil
+    true
+  end
+
+  def self.has_symbols? x
+    if x.is_a? Hash
+      x.each do |k,v|
+        return true if has_symbols?(k) or has_symbols?(v)
+      end
+      false
+    elsif x.is_a? Array
+      x.each do |k|
+        return true if has_symbols?(k)
+      end
+      false
+    else
+      (x.class == Symbol)
+    end
+  end
+
+  def self.recursive_stringify x
+    if x.is_a? Hash
+      Hash[x.collect do |k,v|
+             [recursive_stringify(k), recursive_stringify(v)]
+           end]
+    elsif x.is_a? Array
+      x.collect do |k|
+        recursive_stringify k
+      end
+    elsif x.is_a? Symbol
+      x.to_s
+    else
+      x
+    end
   end
 
   def ensure_serialized_attribute_type
@@ -210,13 +305,31 @@ class ArvadosModel < ActiveRecord::Base
     # developer.
     self.class.serialized_attributes.each do |colname, attr|
       if attr.object_class
-        unless self.attributes[colname].is_a? attr.object_class
-          self.errors.add colname.to_sym, "must be a #{attr.object_class.to_s}"
+        if self.attributes[colname].class != attr.object_class
+          self.errors.add colname.to_sym, "must be a #{attr.object_class.to_s}, not a #{self.attributes[colname].class.to_s}"
+        elsif self.class.has_symbols? attributes[colname]
+          self.errors.add colname.to_sym, "must not contain symbols: #{attributes[colname].inspect}"
         end
       end
     end
   end
 
+  def convert_serialized_symbols_to_strings
+    # ensure_serialized_attribute_type should prevent symbols from
+    # getting into the database in the first place. If someone managed
+    # to get them into the database (perhaps using an older version)
+    # we'll convert symbols to strings when loading from the
+    # database. (Otherwise, loading and saving an object with existing
+    # symbols in a serialized field will crash.)
+    self.class.serialized_attributes.each do |colname, attr|
+      if self.class.has_symbols? attributes[colname]
+        attributes[colname] = self.class.recursive_stringify attributes[colname]
+        self.send(colname + '=',
+                  self.class.recursive_stringify(attributes[colname]))
+      end
+    end
+  end
+
   def foreign_key_attributes
     attributes.keys.select { |a| a.match /_uuid$/ }
   end