AdGuardHome/internal/aghtest/upstream.go

176 lines
4.1 KiB
Go

package aghtest
import (
"crypto/sha256"
"encoding/hex"
"fmt"
"net"
"strings"
"testing"
"github.com/AdguardTeam/golibs/errors"
"github.com/miekg/dns"
"github.com/stretchr/testify/require"
)
// Additional Upstream Testing Utilities
// Upstream is a mock implementation of upstream.Upstream.
//
// TODO(a.garipov): Replace with UpstreamMock and rename it to just Upstream.
type Upstream struct {
// CName is a map of hostname to canonical name.
CName map[string][]string
// IPv4 is a map of hostname to IPv4.
IPv4 map[string][]net.IP
// IPv6 is a map of hostname to IPv6.
IPv6 map[string][]net.IP
// Reverse is a map of address to domain name.
Reverse map[string][]string
// Addr is the address for Address method.
Addr string
}
// RespondTo returns a response with answer if req has class cl, question type
// qt, and target targ.
func RespondTo(t testing.TB, req *dns.Msg, cl, qt uint16, targ, answer string) (resp *dns.Msg) {
t.Helper()
require.NotNil(t, req)
require.Len(t, req.Question, 1)
q := req.Question[0]
targ = dns.Fqdn(targ)
if q.Qclass != cl || q.Qtype != qt || q.Name != targ {
return nil
}
respHdr := dns.RR_Header{
Name: targ,
Rrtype: qt,
Class: cl,
Ttl: 60,
}
resp = new(dns.Msg).SetReply(req)
switch qt {
case dns.TypePTR:
resp.Answer = []dns.RR{
&dns.PTR{
Hdr: respHdr,
Ptr: answer,
},
}
default:
t.Fatalf("unsupported question type: %s", dns.Type(qt))
}
return resp
}
// Exchange implements the upstream.Upstream interface for *Upstream.
//
// TODO(a.garipov): Split further into handlers.
func (u *Upstream) Exchange(m *dns.Msg) (resp *dns.Msg, err error) {
resp = new(dns.Msg).SetReply(m)
if len(m.Question) == 0 {
return nil, fmt.Errorf("question should not be empty")
}
q := m.Question[0]
name := q.Name
for _, cname := range u.CName[name] {
resp.Answer = append(resp.Answer, &dns.CNAME{
Hdr: dns.RR_Header{Name: name, Rrtype: dns.TypeCNAME},
Target: cname,
})
}
qtype := q.Qtype
hdr := dns.RR_Header{
Name: name,
Rrtype: qtype,
}
switch qtype {
case dns.TypeA:
for _, ip := range u.IPv4[name] {
resp.Answer = append(resp.Answer, &dns.A{Hdr: hdr, A: ip})
}
case dns.TypeAAAA:
for _, ip := range u.IPv6[name] {
resp.Answer = append(resp.Answer, &dns.AAAA{Hdr: hdr, AAAA: ip})
}
case dns.TypePTR:
for _, name := range u.Reverse[name] {
resp.Answer = append(resp.Answer, &dns.PTR{Hdr: hdr, Ptr: name})
}
}
if len(resp.Answer) == 0 {
resp.SetRcode(m, dns.RcodeNameError)
}
return resp, nil
}
// Address implements upstream.Upstream interface for *Upstream.
func (u *Upstream) Address() string {
return u.Addr
}
// NewBlockUpstream returns an [*UpstreamMock] that works like an upstream that
// supports hash-based safe-browsing/adult-blocking feature. If shouldBlock is
// true, hostname's actual hash is returned, blocking it. Otherwise, it returns
// a different hash.
func NewBlockUpstream(hostname string, shouldBlock bool) (u *UpstreamMock) {
hash := sha256.Sum256([]byte(hostname))
hashStr := hex.EncodeToString(hash[:])
if !shouldBlock {
hashStr = hex.EncodeToString(hash[:])[:2] + strings.Repeat("ab", 28)
}
ans := &dns.TXT{
Hdr: dns.RR_Header{
Name: "",
Rrtype: dns.TypeTXT,
Class: dns.ClassINET,
Ttl: 60,
},
Txt: []string{hashStr},
}
respTmpl := &dns.Msg{
Answer: []dns.RR{ans},
}
return &UpstreamMock{
OnAddress: func() (addr string) {
return "sbpc.upstream.example"
},
OnExchange: func(req *dns.Msg) (resp *dns.Msg, err error) {
resp = respTmpl.Copy()
resp.SetReply(req)
resp.Answer[0].(*dns.TXT).Hdr.Name = req.Question[0].Name
return resp, nil
},
}
}
// ErrUpstream is the error returned from the [*UpstreamMock] created by
// [NewErrorUpstream].
const ErrUpstream errors.Error = "test upstream error"
// NewErrorUpstream returns an [*UpstreamMock] that returns [ErrUpstream] from
// its Exchange method.
func NewErrorUpstream() (u *UpstreamMock) {
return &UpstreamMock{
OnAddress: func() (addr string) {
return "error.upstream.example"
},
OnExchange: func(_ *dns.Msg) (resp *dns.Msg, err error) {
return nil, errors.Error("test upstream error")
},
}
}