4b8cae692bReducing the errors is not done in a perfect way. We have documented the most striking differences inside https://github.com/ooni/probe/issues/1707#issuecomment-942283746 and some attempts to improve the situation further inside https://github.com/ooni/probe/issues/1707#issuecomment-942341255. A better strategy for the future would be to introduce more specific timeout errors, such as dns_timeout_error, etc. More testing may be needed to further validate and compare the old and the new TH, but this requires Jafar improvements to more precisely simulate more complex censorship.
66 lines
1.8 KiB
Go
66 lines
1.8 KiB
Go
package webconnectivity
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import (
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"context"
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"sync"
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"github.com/ooni/probe-cli/v3/internal/engine/experiment/webconnectivity"
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"github.com/ooni/probe-cli/v3/internal/engine/netx"
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"github.com/ooni/probe-cli/v3/internal/engine/netx/archival"
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"github.com/ooni/probe-cli/v3/internal/netxlite"
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)
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// newfailure is a convenience shortcut to save typing
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var newfailure = archival.NewFailure
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// CtrlDNSResult is the result of the DNS check performed by
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// the Web Connectivity test helper.
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type CtrlDNSResult = webconnectivity.ControlDNSResult
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// DNSConfig configures the DNS check.
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type DNSConfig struct {
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Domain string
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Out chan CtrlDNSResult
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Resolver netx.Resolver
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Wg *sync.WaitGroup
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}
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// DNSDo performs the DNS check.
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func DNSDo(ctx context.Context, config *DNSConfig) {
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defer config.Wg.Done()
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addrs, err := config.Resolver.LookupHost(ctx, config.Domain)
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if addrs == nil {
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addrs = []string{} // fix: the old test helper did that
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}
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failure := dnsMapFailure(newfailure(err))
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config.Out <- CtrlDNSResult{Failure: failure, Addrs: addrs}
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}
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// dnsMapFailure attempts to map netxlite failures to the strings
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// used by the original OONI test helper.
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//
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// See https://github.com/ooni/backend/blob/6ec4fda5b18/oonib/testhelpers/http_helpers.py#L430
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func dnsMapFailure(failure *string) *string {
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switch failure {
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case nil:
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return nil
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default:
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switch *failure {
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case netxlite.FailureDNSNXDOMAINError:
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// We have a name for this string because dnsanalysis.go is
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// already checking for this specific error string.
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s := webconnectivity.DNSNameError
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return &s
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case netxlite.FailureDNSNoAnswer,
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netxlite.FailureDNSNonRecoverableFailure,
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netxlite.FailureDNSRefusedError,
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netxlite.FailureDNSServerMisbehaving,
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netxlite.FailureDNSTemporaryFailure:
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s := "dns_server_failure"
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return &s
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default:
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s := "unknown_error"
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return &s
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}
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}
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}
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