X-Git-Url: https://git.arvados.org/arvados.git/blobdiff_plain/ad79a64bd1503e1e47d3849a00b894c4a6bc9810..cf32ef421c037692e7ae896f695c61d8e3670f01:/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 25d73178c7..4faa0d041f 100644
--- a/services/api/app/models/arvados_model.rb
+++ b/services/api/app/models/arvados_model.rb
@@ -9,10 +9,11 @@ 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
@@ -22,7 +23,10 @@ class ArvadosModel < ActiveRecord::Base
   validate :normalize_collection_uuids
   validate :ensure_valid_uuids
 
-  has_many :permissions, :foreign_key => :head_uuid, :class_name => 'Link', :primary_key => :uuid, :conditions => "link_class = 'permission'"
+  # 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'", dependent: :destroy
 
   class PermissionDeniedError < StandardError
     def http_status
@@ -47,9 +51,7 @@ class ArvadosModel < ActiveRecord::Base
   def self.searchable_columns operator
     textonly_operator = !operator.match(/[<=>]/)
     self.columns.collect do |col|
-      if col.name == 'owner_uuid'
-        nil
-      elsif [:string, :text].index(col.type)
+      if [:string, :text].index(col.type)
         col.name
       elsif !textonly_operator and [:datetime, :integer].index(col.type)
         col.name
@@ -61,32 +63,87 @@ class ArvadosModel < ActiveRecord::Base
     self.columns.select { |col| col.name == attr.to_s }.first
   end
 
-  # def eager_load_associations
-  #   self.class.columns.each do |col|
-  #     re = col.name.match /^(.*)_kind$/
-  #     if (re and
-  #         self.respond_to? re[1].to_sym and
-  #         (auuid = self.send((re[1] + '_uuid').to_sym)) and
-  #         (aclass = self.class.kind_class(self.send(col.name.to_sym))) and
-  #         (aobject = aclass.where('uuid=?', auuid).first))
-  #       self.instance_variable_set('@'+re[1], aobject)
-  #     end
-  #   end
-  # end
-
-  def self.readable_by user
-    uuid_list = [user.uuid, *user.groups_i_can(:read)]
-    sanitized_uuid_list = uuid_list.
-      collect { |uuid| sanitize(uuid) }.join(', ')
-    or_references_me = ''
-    if self == Link and user
-      or_references_me = "OR (#{table_name}.link_class in (#{sanitize 'permission'}, #{sanitize 'resources'}) AND #{sanitize user.uuid} IN (#{table_name}.head_uuid, #{table_name}.tail_uuid))"
+  # 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
+  # function.
+  def self.readable_by(*users_list)
+    # Get rid of troublesome nils
+    users_list.compact!
+
+    # Check if any of the users are admin.  If so, we're done.
+    if users_list.select { |u| u.is_admin }.empty?
+
+      # Collect the uuids for each user and any groups readable by each user.
+      user_uuids = users_list.map { |u| u.uuid }
+      uuid_list = user_uuids + users_list.flat_map { |u| u.groups_i_can(:read) }
+      sanitized_uuid_list = uuid_list.
+        collect { |uuid| sanitize(uuid) }.join(', ')
+      sql_conds = []
+      sql_params = []
+      or_object_uuid = ''
+
+      # This row is owned by a member of users_list, or owned by a group
+      # readable by a member of users_list
+      # or
+      # This row uuid is the uuid of a member of users_list
+      # or
+      # 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 (?)",
+                    "#{table_name}.uuid IN #{permitted_uuids}"]
+      sql_params += [uuid_list, user_uuids]
+
+      if self == Link and users_list.any?
+        # This row is a 'permission' or 'resources' link class
+        # The uuid for a member of users_list is referenced in either the head
+        # or tail of the link
+        sql_conds += ["(#{table_name}.link_class in (#{sanitize 'permission'}, #{sanitize 'resources'}) AND (#{table_name}.head_uuid IN (?) OR #{table_name}.tail_uuid IN (?)))"]
+        sql_params += [user_uuids, user_uuids]
+      end
+
+      if self == Log and users_list.any?
+        # Link head points to the object described by this row
+        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 (?)"]
+        sql_params += [uuid_list]
+      end
+
+      # Link head points to this row, or to the owner of this row (the thing to be read)
+      #
+      # Link tail originates from this user, or a group that is readable by this
+      # user (the identity with authorization to read)
+      #
+      # Link class is 'permission' ('write' and 'manage' implicitly include 'read')
+      where(sql_conds.join(' OR '), *sql_params)
+    else
+      # At least one user is admin, so don't bother to apply any restrictions.
+      self
     end
-    joins("LEFT JOIN links permissions ON permissions.head_uuid in (#{table_name}.owner_uuid, #{table_name}.uuid) AND permissions.tail_uuid in (#{sanitized_uuid_list}) AND permissions.link_class='permission'").
-      where("?=? OR #{table_name}.owner_uuid in (?) OR #{table_name}.uuid=? OR permissions.head_uuid IS NOT NULL #{or_references_me}",
-            true, user.is_admin,
-            uuid_list,
-            user.uuid)
   end
 
   def logged_attributes
@@ -95,16 +152,71 @@ 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
@@ -121,24 +233,12 @@ 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 destroy_permission_links
+    Link.destroy_all(['link_class=? and (head_uuid=? or tail_uuid=?)',
+                      'permission', uuid, uuid])
   end
 
   def ensure_permission_to_destroy
@@ -151,6 +251,7 @@ 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
@@ -159,6 +260,7 @@ 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 ensure_serialized_attribute_type
@@ -253,7 +355,7 @@ class ArvadosModel < ActiveRecord::Base
       self.class.kind
     end
 
-    def self.readable_by (u)
+    def self.readable_by (*u)
       self
     end
 
@@ -295,6 +397,7 @@ class ArvadosModel < ActiveRecord::Base
     log = Log.new(event_type: event_type).fill_object(self)
     yield log
     log.save!
+    connection.execute "NOTIFY logs, '#{log.id}'"
     log_start_state
   end