Pull request #1558: add-dnssvc

Merge in DNS/adguard-home from add-dnssvc to master

Squashed commit of the following:

commit 55f4f114bab65a03c0d65383e89020a7356cff32
Merge: 95dc28d9 6e63757f
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Mon Aug 15 20:53:07 2022 +0300

    Merge branch 'master' into add-dnssvc

commit 95dc28d9d77d06e8ac98c1e6772557bffbf1705b
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Mon Aug 15 20:52:50 2022 +0300

    all: imp tests, docs

commit 0d9d02950d84afd160b4b1c118da856cee6f12e5
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Thu Aug 11 19:27:59 2022 +0300

    all: imp docs

commit 8990e038a81da4430468da12fcebedf79fe14df6
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Thu Aug 11 19:05:29 2022 +0300

    all: imp tests more

commit 92730d93a2a1ac77888c2655508e43efaf0e9fde
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Thu Aug 11 18:37:48 2022 +0300

    all: imp tests more

commit 8cd45ba30da7ac310e9dc666fb2af438e577b02d
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Thu Aug 11 18:11:15 2022 +0300

    all: add v1 dnssvc stub; refactor tests
This commit is contained in:
Ainar Garipov
2022-08-16 13:21:25 +03:00
parent 6e63757fc7
commit d4c3a43bcb
19 changed files with 742 additions and 319 deletions

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@@ -0,0 +1,193 @@
// Package dnssvc contains the AdGuard Home DNS service.
//
// TODO(a.garipov): Define, if all methods of a *Service should work with a nil
// receiver.
package dnssvc
import (
"context"
"fmt"
"net"
"net/netip"
"time"
"github.com/AdguardTeam/AdGuardHome/internal/v1/agh"
// TODO(a.garipov): Add a “dnsproxy proxy” package to shield us from changes
// and replacement of module dnsproxy.
"github.com/AdguardTeam/dnsproxy/proxy"
"github.com/AdguardTeam/dnsproxy/upstream"
)
// Config is the AdGuard Home DNS service configuration structure.
//
// TODO(a.garipov): Add timeout for incoming requests.
type Config struct {
// Addresses are the addresses on which to serve plain DNS queries.
Addresses []netip.AddrPort
// Upstreams are the DNS upstreams to use. If not set, upstreams are
// created using data from BootstrapServers, UpstreamServers, and
// UpstreamTimeout.
//
// TODO(a.garipov): Think of a better scheme. Those other three parameters
// are here only to make Config work properly.
Upstreams []upstream.Upstream
// BootstrapServers are the addresses for bootstrapping the upstream DNS
// server addresses.
BootstrapServers []string
// UpstreamServers are the upstream DNS server addresses to use.
UpstreamServers []string
// UpstreamTimeout is the timeout for upstream requests.
UpstreamTimeout time.Duration
}
// Service is the AdGuard Home DNS service. A nil *Service is a valid
// [agh.Service] that does nothing.
type Service struct {
proxy *proxy.Proxy
bootstraps []string
upstreams []string
upsTimeout time.Duration
}
// New returns a new properly initialized *Service. If c is nil, svc is a nil
// *Service that does nothing. The fields of c must not be modified after
// calling New.
func New(c *Config) (svc *Service, err error) {
if c == nil {
return nil, nil
}
svc = &Service{
bootstraps: c.BootstrapServers,
upstreams: c.UpstreamServers,
upsTimeout: c.UpstreamTimeout,
}
var upstreams []upstream.Upstream
if len(c.Upstreams) > 0 {
upstreams = c.Upstreams
} else {
upstreams, err = addressesToUpstreams(
c.UpstreamServers,
c.BootstrapServers,
c.UpstreamTimeout,
)
if err != nil {
return nil, fmt.Errorf("converting upstreams: %w", err)
}
}
svc.proxy = &proxy.Proxy{
Config: proxy.Config{
UDPListenAddr: udpAddrs(c.Addresses),
TCPListenAddr: tcpAddrs(c.Addresses),
UpstreamConfig: &proxy.UpstreamConfig{
Upstreams: upstreams,
},
},
}
err = svc.proxy.Init()
if err != nil {
return nil, fmt.Errorf("proxy: %w", err)
}
return svc, nil
}
// addressesToUpstreams is a wrapper around [upstream.AddressToUpstream]. It
// accepts a slice of addresses and other upstream parameters, and returns a
// slice of upstreams.
func addressesToUpstreams(
upsStrs []string,
bootstraps []string,
timeout time.Duration,
) (upstreams []upstream.Upstream, err error) {
upstreams = make([]upstream.Upstream, len(upsStrs))
for i, upsStr := range upsStrs {
upstreams[i], err = upstream.AddressToUpstream(upsStr, &upstream.Options{
Bootstrap: bootstraps,
Timeout: timeout,
})
if err != nil {
return nil, fmt.Errorf("upstream at index %d: %w", i, err)
}
}
return upstreams, nil
}
// tcpAddrs converts []netip.AddrPort into []*net.TCPAddr.
func tcpAddrs(addrPorts []netip.AddrPort) (tcpAddrs []*net.TCPAddr) {
if addrPorts == nil {
return nil
}
tcpAddrs = make([]*net.TCPAddr, len(addrPorts))
for i, a := range addrPorts {
tcpAddrs[i] = net.TCPAddrFromAddrPort(a)
}
return tcpAddrs
}
// udpAddrs converts []netip.AddrPort into []*net.UDPAddr.
func udpAddrs(addrPorts []netip.AddrPort) (udpAddrs []*net.UDPAddr) {
if addrPorts == nil {
return nil
}
udpAddrs = make([]*net.UDPAddr, len(addrPorts))
for i, a := range addrPorts {
udpAddrs[i] = net.UDPAddrFromAddrPort(a)
}
return udpAddrs
}
// type check
var _ agh.Service = (*Service)(nil)
// Start implements the [agh.Service] interface for *Service. svc may be nil.
// After Start exits, all DNS servers have tried to start, but there is no
// guarantee that they did. Errors from the servers are written to the log.
func (svc *Service) Start() (err error) {
if svc == nil {
return nil
}
return svc.proxy.Start()
}
// Shutdown implements the [agh.Service] interface for *Service. svc may be
// nil.
func (svc *Service) Shutdown(ctx context.Context) (err error) {
if svc == nil {
return nil
}
return svc.proxy.Stop()
}
// Config returns the current configuration of the web service.
func (svc *Service) Config() (c *Config) {
// TODO(a.garipov): Do we need to get the TCP addresses separately?
udpAddrs := svc.proxy.Addrs(proxy.ProtoUDP)
addrs := make([]netip.AddrPort, len(udpAddrs))
for i, a := range udpAddrs {
addrs[i] = a.(*net.UDPAddr).AddrPort()
}
c = &Config{
Addresses: addrs,
BootstrapServers: svc.bootstraps,
UpstreamServers: svc.upstreams,
UpstreamTimeout: svc.upsTimeout,
}
return c
}

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@@ -0,0 +1,89 @@
package dnssvc_test
import (
"context"
"net/netip"
"testing"
"time"
"github.com/AdguardTeam/AdGuardHome/internal/aghtest"
"github.com/AdguardTeam/AdGuardHome/internal/v1/dnssvc"
"github.com/AdguardTeam/dnsproxy/upstream"
"github.com/miekg/dns"
"github.com/stretchr/testify/assert"
"github.com/stretchr/testify/require"
)
func TestMain(m *testing.M) {
aghtest.DiscardLogOutput(m)
}
// testTimeout is the common timeout for tests.
const testTimeout = 100 * time.Millisecond
func TestService(t *testing.T) {
const (
bootstrapAddr = "bootstrap.example"
upstreamAddr = "upstream.example"
)
ups := &aghtest.UpstreamMock{
OnAddress: func() (addr string) {
return upstreamAddr
},
OnExchange: func(req *dns.Msg) (resp *dns.Msg, err error) {
resp = (&dns.Msg{}).SetReply(req)
return resp, nil
},
}
c := &dnssvc.Config{
Addresses: []netip.AddrPort{netip.MustParseAddrPort("127.0.0.1:0")},
Upstreams: []upstream.Upstream{ups},
BootstrapServers: []string{bootstrapAddr},
UpstreamServers: []string{upstreamAddr},
UpstreamTimeout: testTimeout,
}
svc, err := dnssvc.New(c)
require.NoError(t, err)
err = svc.Start()
require.NoError(t, err)
gotConf := svc.Config()
require.NotNil(t, gotConf)
require.Len(t, gotConf.Addresses, 1)
addr := gotConf.Addresses[0]
t.Run("dns", func(t *testing.T) {
req := &dns.Msg{
MsgHdr: dns.MsgHdr{
Id: dns.Id(),
RecursionDesired: true,
},
Question: []dns.Question{{
Name: "example.com.",
Qtype: dns.TypeA,
Qclass: dns.ClassINET,
}},
}
ctx, cancel := context.WithTimeout(context.Background(), testTimeout)
defer cancel()
cli := &dns.Client{}
resp, _, excErr := cli.ExchangeContext(ctx, req, addr.String())
require.NoError(t, excErr)
assert.NotNil(t, resp)
})
ctx, cancel := context.WithTimeout(context.Background(), testTimeout)
defer cancel()
err = svc.Shutdown(ctx)
require.NoError(t, err)
}