Documentation
¶
Overview ¶
Package dnscheck contains the DNS check experiment.
This experiment is not meant to be an user facing experiment rather it is meant to be a building block for building DNS experiments.
Description of the experiment ¶
You run this experiment with one or more DNS server URLs in input. We describe the format of such URLs later.
For each DNS server URL, the code behaves as follows:
1. if the URL's hostname is a domain name, we resolve such domain name using the system resolver and attempt to query the selected resolver using all the possible IP addresses, so to verify all of them
2. otherwise, we directly attempt to use the specified resolver
The purpose of this algorithm is to make sure we measure whether each possible IP address for the domain is working or not.
By default, we resolve `example.org`. There is an experiment option called Domain allowing you to change that.
Input URL format ¶
To perform DNS over UDP, use `udp://<address_or_domain>[:<port>]`.
To perform DNS over TCP, use `tcp://<address_or_domain>[:<port>]`.
For DNS over TLS, use `dot://<address_or_domain>[:<port>]`.
For DNS over HTTPS, use `https://<address_or_domain>[:<port>]/<path>`.
When the `<port>` is missing, we use the correct default.
Output data format ¶
A measurement data structure is generated for every input resolver URL using the format described above. Because a single URL might expand to one or more IP addresses, the toplevel output data format is a map.
The map key is the TCP or UDP destination endpoint being used. The map value is the measurement for such endpoint.
Index ¶
Constants ¶
This section is empty.
Variables ¶
var ( ErrInputRequired = errors.New("this experiment needs input") ErrInvalidURL = errors.New("the input URL is invalid") ErrUnsupportedURLScheme = errors.New("unsupported URL scheme") )
The following errors may be returned by this experiment. Of course these errors are in addition to any other errors returned by the low level packages that are used by this experiment to implement its functionality.
Functions ¶
func Collect ¶
func Collect(ctx context.Context, multi urlgetter.Multi, inputs []urlgetter.MultiInput, callbacks model.ExperimentCallbacks) <-chan urlgetter.MultiOutput
Collect prints on the output channel the result of running dnscheck on every provided input. It closes the output channel when done.
func NewExperimentMeasurer ¶
func NewExperimentMeasurer(config Config) model.ExperimentMeasurer
NewExperimentMeasurer creates a new ExperimentMeasurer.
Types ¶
type Config ¶
type Config struct {
Domain string `ooni:"domain to resolve using the specified resolver"`
}
Config contains the experiment's configuration.
type Measurer ¶
type Measurer struct {
Config
}
Measurer performs the measurement.
func (Measurer) ExperimentName ¶
ExperimentName implements model.ExperimentSession.ExperimentName
func (Measurer) ExperimentVersion ¶
ExperimentVersion implements model.ExperimentSession.ExperimentVersion
func (Measurer) Run ¶
func (m Measurer) Run( ctx context.Context, sess model.ExperimentSession, measurement *model.Measurement, callbacks model.ExperimentCallbacks, ) error
Run implements model.ExperimentSession.Run
Source Files