273b70bacc
## Checklist - [x] I have read the [contribution guidelines](https://github.com/ooni/probe-cli/blob/master/CONTRIBUTING.md) - [x] reference issue for this pull request: https://github.com/ooni/probe/issues/1885 - [x] related ooni/spec pull request: N/A Location of the issue tracker: https://github.com/ooni/probe ## Description This PR contains a set of changes to move important interfaces and data types into the `./internal/model` package. The criteria for including an interface or data type in here is roughly that the type should be important and used by several packages. We are especially interested to move more interfaces here to increase modularity. An additional side effect is that, by reading this package, one should be able to understand more quickly how different parts of the codebase interact with each other. This is what I want to move in `internal/model`: - [x] most important interfaces from `internal/netxlite` - [x] everything that was previously part of `internal/engine/model` - [x] mocks from `internal/netxlite/mocks` should also be moved in here as a subpackage
114 lines
2.7 KiB
Go
114 lines
2.7 KiB
Go
package netxlite
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import (
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"context"
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"errors"
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"io"
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"math"
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"net"
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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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// DialContextFunc is the type of net.Dialer.DialContext.
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type DialContextFunc func(context.Context, string, string) (net.Conn, error)
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// DNSOverTCP is a DNS-over-{TCP,TLS} DNSTransport.
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//
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// Bug: this implementation always creates a new connection for each query.
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type DNSOverTCP struct {
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dial DialContextFunc
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address string
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network string
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requiresPadding bool
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}
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// NewDNSOverTCP creates a new DNSOverTCP transport.
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//
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// Arguments:
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//
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// - dial is a function with the net.Dialer.DialContext's signature;
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//
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// - address is the endpoint address (e.g., 8.8.8.8:53).
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func NewDNSOverTCP(dial DialContextFunc, address string) *DNSOverTCP {
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return &DNSOverTCP{
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dial: dial,
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address: address,
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network: "tcp",
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requiresPadding: false,
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}
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}
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// NewDNSOverTLS creates a new DNSOverTLS transport.
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//
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// Arguments:
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//
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// - dial is a function with the net.Dialer.DialContext's signature;
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//
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// - address is the endpoint address (e.g., 8.8.8.8:853).
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func NewDNSOverTLS(dial DialContextFunc, address string) *DNSOverTCP {
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return &DNSOverTCP{
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dial: dial,
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address: address,
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network: "dot",
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requiresPadding: true,
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}
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}
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// RoundTrip sends a query and receives a reply.
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func (t *DNSOverTCP) RoundTrip(ctx context.Context, query []byte) ([]byte, error) {
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if len(query) > math.MaxUint16 {
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return nil, errors.New("query too long")
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}
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conn, err := t.dial(ctx, "tcp", t.address)
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if err != nil {
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return nil, err
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}
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defer conn.Close()
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if err = conn.SetDeadline(time.Now().Add(10 * time.Second)); err != nil {
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return nil, err
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}
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// Write request
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buf := []byte{byte(len(query) >> 8)}
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buf = append(buf, byte(len(query)))
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buf = append(buf, query...)
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if _, err = conn.Write(buf); err != nil {
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return nil, err
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}
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// Read response
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header := make([]byte, 2)
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if _, err = io.ReadFull(conn, header); err != nil {
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return nil, err
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}
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length := int(header[0])<<8 | int(header[1])
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reply := make([]byte, length)
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if _, err = io.ReadFull(conn, reply); err != nil {
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return nil, err
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}
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return reply, nil
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}
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// RequiresPadding returns true for DoT and false for TCP
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// according to RFC8467.
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func (t *DNSOverTCP) RequiresPadding() bool {
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return t.requiresPadding
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}
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// Network returns the transport network, i.e., "dot" or "tcp".
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func (t *DNSOverTCP) Network() string {
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return t.network
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}
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// Address returns the upstream server endpoint (e.g., "1.1.1.1:853").
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func (t *DNSOverTCP) Address() string {
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return t.address
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}
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// CloseIdleConnections closes idle connections, if any.
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func (t *DNSOverTCP) CloseIdleConnections() {
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// nothing to do
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}
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var _ model.DNSTransport = &DNSOverTCP{}
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