DNS: Fix some bugs; Refactors; Optimizations (#4659)

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patterniha 2025-04-29 12:09:57 +03:30 committed by GitHub
parent 1c4e246788
commit aa4134f4a6
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GPG key ID: B5690EEEBB952194
22 changed files with 658 additions and 978 deletions

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@ -4,23 +4,20 @@ import (
"bytes"
"context"
"encoding/binary"
go_errors "errors"
"net/url"
"sync"
"time"
"github.com/quic-go/quic-go"
"github.com/xtls/xray-core/common"
"github.com/xtls/xray-core/common/buf"
"github.com/xtls/xray-core/common/errors"
"github.com/xtls/xray-core/common/log"
"github.com/xtls/xray-core/common/net"
"github.com/xtls/xray-core/common/protocol/dns"
"github.com/xtls/xray-core/common/session"
"github.com/xtls/xray-core/common/signal/pubsub"
"github.com/xtls/xray-core/common/task"
dns_feature "github.com/xtls/xray-core/features/dns"
"github.com/xtls/xray-core/transport/internet/tls"
"golang.org/x/net/dns/dnsmessage"
"golang.org/x/net/http2"
)
@ -33,17 +30,14 @@ const handshakeTimeout = time.Second * 8
// QUICNameServer implemented DNS over QUIC
type QUICNameServer struct {
sync.RWMutex
ips map[string]*record
pub *pubsub.Service
cleanup *task.Periodic
name string
destination *net.Destination
connection quic.Connection
queryStrategy QueryStrategy
cacheController *CacheController
destination *net.Destination
connection quic.Connection
clientIP net.IP
}
// NewQUICNameServer creates DNS-over-QUIC client object for local resolving
func NewQUICNameServer(url *url.URL, queryStrategy QueryStrategy) (*QUICNameServer, error) {
func NewQUICNameServer(url *url.URL, disableCache bool, clientIP net.IP) (*QUICNameServer, error) {
errors.LogInfo(context.Background(), "DNS: created Local DNS-over-QUIC client for ", url.String())
var err error
@ -57,15 +51,9 @@ func NewQUICNameServer(url *url.URL, queryStrategy QueryStrategy) (*QUICNameServ
dest := net.UDPDestination(net.ParseAddress(url.Hostname()), port)
s := &QUICNameServer{
ips: make(map[string]*record),
pub: pubsub.NewService(),
name: url.String(),
destination: &dest,
queryStrategy: queryStrategy,
}
s.cleanup = &task.Periodic{
Interval: time.Minute,
Execute: s.Cleanup,
cacheController: NewCacheController(url.String(), disableCache),
destination: &dest,
clientIP: clientIP,
}
return s, nil
@ -73,94 +61,17 @@ func NewQUICNameServer(url *url.URL, queryStrategy QueryStrategy) (*QUICNameServ
// Name returns client name
func (s *QUICNameServer) Name() string {
return s.name
}
// Cleanup clears expired items from cache
func (s *QUICNameServer) Cleanup() error {
now := time.Now()
s.Lock()
defer s.Unlock()
if len(s.ips) == 0 {
return errors.New("nothing to do. stopping...")
}
for domain, record := range s.ips {
if record.A != nil && record.A.Expire.Before(now) {
record.A = nil
}
if record.AAAA != nil && record.AAAA.Expire.Before(now) {
record.AAAA = nil
}
if record.A == nil && record.AAAA == nil {
errors.LogDebug(context.Background(), s.name, " cleanup ", domain)
delete(s.ips, domain)
} else {
s.ips[domain] = record
}
}
if len(s.ips) == 0 {
s.ips = make(map[string]*record)
}
return nil
}
func (s *QUICNameServer) updateIP(req *dnsRequest, ipRec *IPRecord) {
elapsed := time.Since(req.start)
s.Lock()
rec, found := s.ips[req.domain]
if !found {
rec = &record{}
}
updated := false
switch req.reqType {
case dnsmessage.TypeA:
if isNewer(rec.A, ipRec) {
rec.A = ipRec
updated = true
}
case dnsmessage.TypeAAAA:
addr := make([]net.Address, 0)
for _, ip := range ipRec.IP {
if len(ip.IP()) == net.IPv6len {
addr = append(addr, ip)
}
}
ipRec.IP = addr
if isNewer(rec.AAAA, ipRec) {
rec.AAAA = ipRec
updated = true
}
}
errors.LogInfo(context.Background(), s.name, " got answer: ", req.domain, " ", req.reqType, " -> ", ipRec.IP, " ", elapsed)
if updated {
s.ips[req.domain] = rec
}
switch req.reqType {
case dnsmessage.TypeA:
s.pub.Publish(req.domain+"4", nil)
case dnsmessage.TypeAAAA:
s.pub.Publish(req.domain+"6", nil)
}
s.Unlock()
common.Must(s.cleanup.Start())
return s.cacheController.name
}
func (s *QUICNameServer) newReqID() uint16 {
return 0
}
func (s *QUICNameServer) sendQuery(ctx context.Context, domain string, clientIP net.IP, option dns_feature.IPOption) {
errors.LogInfo(ctx, s.name, " querying: ", domain)
func (s *QUICNameServer) sendQuery(ctx context.Context, noResponseErrCh chan<- error, domain string, option dns_feature.IPOption) {
errors.LogInfo(ctx, s.Name(), " querying: ", domain)
reqs := buildReqMsgs(domain, option, s.newReqID, genEDNS0Options(clientIP, 0))
reqs := buildReqMsgs(domain, option, s.newReqID, genEDNS0Options(s.clientIP, 0))
var deadline time.Time
if d, ok := ctx.Deadline(); ok {
@ -192,23 +103,36 @@ func (s *QUICNameServer) sendQuery(ctx context.Context, domain string, clientIP
b, err := dns.PackMessage(r.msg)
if err != nil {
errors.LogErrorInner(ctx, err, "failed to pack dns query")
noResponseErrCh <- err
return
}
dnsReqBuf := buf.New()
binary.Write(dnsReqBuf, binary.BigEndian, uint16(b.Len()))
dnsReqBuf.Write(b.Bytes())
err = binary.Write(dnsReqBuf, binary.BigEndian, uint16(b.Len()))
if err != nil {
errors.LogErrorInner(ctx, err, "binary write failed")
noResponseErrCh <- err
return
}
_, err = dnsReqBuf.Write(b.Bytes())
if err != nil {
errors.LogErrorInner(ctx, err, "buffer write failed")
noResponseErrCh <- err
return
}
b.Release()
conn, err := s.openStream(dnsCtx)
if err != nil {
errors.LogErrorInner(ctx, err, "failed to open quic connection")
noResponseErrCh <- err
return
}
_, err = conn.Write(dnsReqBuf.Bytes())
if err != nil {
errors.LogErrorInner(ctx, err, "failed to send query")
noResponseErrCh <- err
return
}
@ -219,136 +143,81 @@ func (s *QUICNameServer) sendQuery(ctx context.Context, domain string, clientIP
n, err := respBuf.ReadFullFrom(conn, 2)
if err != nil && n == 0 {
errors.LogErrorInner(ctx, err, "failed to read response length")
noResponseErrCh <- err
return
}
var length int16
err = binary.Read(bytes.NewReader(respBuf.Bytes()), binary.BigEndian, &length)
if err != nil {
errors.LogErrorInner(ctx, err, "failed to parse response length")
noResponseErrCh <- err
return
}
respBuf.Clear()
n, err = respBuf.ReadFullFrom(conn, int32(length))
if err != nil && n == 0 {
errors.LogErrorInner(ctx, err, "failed to read response length")
noResponseErrCh <- err
return
}
rec, err := parseResponse(respBuf.Bytes())
if err != nil {
errors.LogErrorInner(ctx, err, "failed to handle response")
noResponseErrCh <- err
return
}
s.updateIP(r, rec)
s.cacheController.updateIP(r, rec)
}(req)
}
}
func (s *QUICNameServer) findIPsForDomain(domain string, option dns_feature.IPOption) ([]net.IP, uint32, error) {
s.RLock()
record, found := s.ips[domain]
s.RUnlock()
if !found {
return nil, 0, errRecordNotFound
}
var err4 error
var err6 error
var ips []net.Address
var ip6 []net.Address
var ttl uint32
if option.IPv4Enable {
ips, ttl, err4 = record.A.getIPs()
}
if option.IPv6Enable {
ip6, ttl, err6 = record.AAAA.getIPs()
ips = append(ips, ip6...)
}
if len(ips) > 0 {
netips, err := toNetIP(ips)
return netips, ttl, err
}
if err4 != nil {
return nil, 0, err4
}
if err6 != nil {
return nil, 0, err6
}
if (option.IPv4Enable && record.A != nil) || (option.IPv6Enable && record.AAAA != nil) {
return nil, 0, dns_feature.ErrEmptyResponse
}
return nil, 0, errRecordNotFound
}
// QueryIP is called from dns.Server->queryIPTimeout
func (s *QUICNameServer) QueryIP(ctx context.Context, domain string, clientIP net.IP, option dns_feature.IPOption, disableCache bool) ([]net.IP, uint32, error) {
func (s *QUICNameServer) QueryIP(ctx context.Context, domain string, option dns_feature.IPOption) ([]net.IP, uint32, error) {
fqdn := Fqdn(domain)
option = ResolveIpOptionOverride(s.queryStrategy, option)
if !option.IPv4Enable && !option.IPv6Enable {
return nil, 0, dns_feature.ErrEmptyResponse
}
sub4, sub6 := s.cacheController.registerSubscribers(fqdn, option)
defer closeSubscribers(sub4, sub6)
if disableCache {
errors.LogDebug(ctx, "DNS cache is disabled. Querying IP for ", domain, " at ", s.name)
if s.cacheController.disableCache {
errors.LogDebug(ctx, "DNS cache is disabled. Querying IP for ", domain, " at ", s.Name())
} else {
ips, ttl, err := s.findIPsForDomain(fqdn, option)
if err == nil || err == dns_feature.ErrEmptyResponse || dns_feature.RCodeFromError(err) == 3 {
errors.LogDebugInner(ctx, err, s.name, " cache HIT ", domain, " -> ", ips)
log.Record(&log.DNSLog{Server: s.name, Domain: domain, Result: ips, Status: log.DNSCacheHit, Elapsed: 0, Error: err})
ips, ttl, err := s.cacheController.findIPsForDomain(fqdn, option)
if !go_errors.Is(err, errRecordNotFound) {
errors.LogDebugInner(ctx, err, s.Name(), " cache HIT ", domain, " -> ", ips)
log.Record(&log.DNSLog{Server: s.Name(), Domain: domain, Result: ips, Status: log.DNSCacheHit, Elapsed: 0, Error: err})
return ips, ttl, err
}
}
// ipv4 and ipv6 belong to different subscription groups
var sub4, sub6 *pubsub.Subscriber
if option.IPv4Enable {
sub4 = s.pub.Subscribe(fqdn + "4")
defer sub4.Close()
}
if option.IPv6Enable {
sub6 = s.pub.Subscribe(fqdn + "6")
defer sub6.Close()
}
done := make(chan interface{})
go func() {
if sub4 != nil {
select {
case <-sub4.Wait():
case <-ctx.Done():
}
}
if sub6 != nil {
select {
case <-sub6.Wait():
case <-ctx.Done():
}
}
close(done)
}()
s.sendQuery(ctx, fqdn, clientIP, option)
noResponseErrCh := make(chan error, 2)
s.sendQuery(ctx, noResponseErrCh, fqdn, option)
start := time.Now()
for {
ips, ttl, err := s.findIPsForDomain(fqdn, option)
if err != errRecordNotFound {
log.Record(&log.DNSLog{Server: s.name, Domain: domain, Result: ips, Status: log.DNSQueried, Elapsed: time.Since(start), Error: err})
return ips, ttl, err
}
if sub4 != nil {
select {
case <-ctx.Done():
return nil, 0, ctx.Err()
case <-done:
case err := <-noResponseErrCh:
return nil, 0, err
case <-sub4.Wait():
sub4.Close()
}
}
if sub6 != nil {
select {
case <-ctx.Done():
return nil, 0, ctx.Err()
case err := <-noResponseErrCh:
return nil, 0, err
case <-sub6.Wait():
sub6.Close()
}
}
ips, ttl, err := s.cacheController.findIPsForDomain(fqdn, option)
log.Record(&log.DNSLog{Server: s.Name(), Domain: domain, Result: ips, Status: log.DNSQueried, Elapsed: time.Since(start), Error: err})
return ips, ttl, err
}
func isActive(s quic.Connection) bool {