01a513a496
This diff refactors the DNSTransport model to receive in input a DNSQuery and return in output a DNSResponse. The design of DNSQuery and DNSResponse takes into account the use case of a transport using getaddrinfo, meaning that we don't need to serialize and deserialize messages when using getaddrinfo. The current codebase does not use a getaddrinfo transport, but I wrote one such a transport in the Websteps Winter 2021 prototype (https://github.com/bassosimone/websteps-illustrated/). The design conversation that lead to producing this diff is https://github.com/ooni/probe/issues/2099
67 lines
1.6 KiB
Go
67 lines
1.6 KiB
Go
package measurex
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//
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// DNSX (DNS eXtensions)
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//
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// We wrap dnsx.RoundTripper to store events into a WritableDB.
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//
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import (
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"context"
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"time"
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"github.com/ooni/probe-cli/v3/internal/model"
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)
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// WrapDNSXRoundTripper creates a new DNSXRoundTripper that
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// saves events into the given WritableDB.
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func (mx *Measurer) WrapDNSXRoundTripper(db WritableDB, rtx model.DNSTransport) model.DNSTransport {
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return &dnsxRoundTripperDB{db: db, DNSTransport: rtx, begin: mx.Begin}
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}
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type dnsxRoundTripperDB struct {
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model.DNSTransport
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begin time.Time
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db WritableDB
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}
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// DNSRoundTripEvent contains the result of a DNS round trip.
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type DNSRoundTripEvent struct {
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Network string
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Address string
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Query []byte
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Started float64
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Finished float64
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Failure *string
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Reply []byte
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}
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func (txp *dnsxRoundTripperDB) RoundTrip(
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ctx context.Context, query model.DNSQuery) (model.DNSResponse, error) {
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started := time.Since(txp.begin).Seconds()
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response, err := txp.DNSTransport.RoundTrip(ctx, query)
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finished := time.Since(txp.begin).Seconds()
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txp.db.InsertIntoDNSRoundTrip(&DNSRoundTripEvent{
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Network: txp.DNSTransport.Network(),
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Address: txp.DNSTransport.Address(),
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Query: txp.maybeQueryBytes(query),
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Started: started,
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Finished: finished,
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Failure: NewFailure(err),
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Reply: txp.maybeResponseBytes(response),
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})
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return response, err
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}
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func (txp *dnsxRoundTripperDB) maybeQueryBytes(query model.DNSQuery) []byte {
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data, _ := query.Bytes()
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return data
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}
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func (txp *dnsxRoundTripperDB) maybeResponseBytes(response model.DNSResponse) []byte {
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if response == nil {
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return nil
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}
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return response.Bytes()
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}
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