mirror of
https://github.com/XTLS/Xray-core.git
synced 2024-12-23 20:03:32 +02:00
417 lines
10 KiB
Go
417 lines
10 KiB
Go
package dns
|
|
|
|
import (
|
|
"bytes"
|
|
"context"
|
|
"fmt"
|
|
"io"
|
|
"net/http"
|
|
"net/url"
|
|
"sync"
|
|
"sync/atomic"
|
|
"time"
|
|
|
|
"github.com/xtls/xray-core/common"
|
|
"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/net/cnc"
|
|
"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/features/routing"
|
|
"github.com/xtls/xray-core/transport/internet"
|
|
"golang.org/x/net/dns/dnsmessage"
|
|
)
|
|
|
|
// DoHNameServer implemented DNS over HTTPS (RFC8484) Wire Format,
|
|
// which is compatible with traditional dns over udp(RFC1035),
|
|
// thus most of the DOH implementation is copied from udpns.go
|
|
type DoHNameServer struct {
|
|
dispatcher routing.Dispatcher
|
|
sync.RWMutex
|
|
ips map[string]*record
|
|
pub *pubsub.Service
|
|
cleanup *task.Periodic
|
|
reqID uint32
|
|
httpClient *http.Client
|
|
dohURL string
|
|
name string
|
|
queryStrategy QueryStrategy
|
|
}
|
|
|
|
// NewDoHNameServer creates DOH server object for remote resolving.
|
|
func NewDoHNameServer(url *url.URL, dispatcher routing.Dispatcher, queryStrategy QueryStrategy) (*DoHNameServer, error) {
|
|
errors.LogInfo(context.Background(), "DNS: created Remote DOH client for ", url.String())
|
|
s := baseDOHNameServer(url, "DOH", queryStrategy)
|
|
|
|
s.dispatcher = dispatcher
|
|
tr := &http.Transport{
|
|
MaxIdleConns: 30,
|
|
IdleConnTimeout: 90 * time.Second,
|
|
TLSHandshakeTimeout: 30 * time.Second,
|
|
ForceAttemptHTTP2: true,
|
|
DialContext: func(ctx context.Context, network, addr string) (net.Conn, error) {
|
|
dest, err := net.ParseDestination(network + ":" + addr)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
link, err := s.dispatcher.Dispatch(toDnsContext(ctx, s.dohURL), dest)
|
|
select {
|
|
case <-ctx.Done():
|
|
return nil, ctx.Err()
|
|
default:
|
|
|
|
}
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
cc := common.ChainedClosable{}
|
|
if cw, ok := link.Writer.(common.Closable); ok {
|
|
cc = append(cc, cw)
|
|
}
|
|
if cr, ok := link.Reader.(common.Closable); ok {
|
|
cc = append(cc, cr)
|
|
}
|
|
return cnc.NewConnection(
|
|
cnc.ConnectionInputMulti(link.Writer),
|
|
cnc.ConnectionOutputMulti(link.Reader),
|
|
cnc.ConnectionOnClose(cc),
|
|
), nil
|
|
},
|
|
}
|
|
s.httpClient = &http.Client{
|
|
Timeout: time.Second * 180,
|
|
Transport: tr,
|
|
}
|
|
|
|
return s, nil
|
|
}
|
|
|
|
// NewDoHLocalNameServer creates DOH client object for local resolving
|
|
func NewDoHLocalNameServer(url *url.URL, queryStrategy QueryStrategy) *DoHNameServer {
|
|
url.Scheme = "https"
|
|
s := baseDOHNameServer(url, "DOHL", queryStrategy)
|
|
tr := &http.Transport{
|
|
IdleConnTimeout: 90 * time.Second,
|
|
ForceAttemptHTTP2: true,
|
|
DialContext: func(ctx context.Context, network, addr string) (net.Conn, error) {
|
|
dest, err := net.ParseDestination(network + ":" + addr)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
conn, err := internet.DialSystem(ctx, dest, nil)
|
|
log.Record(&log.AccessMessage{
|
|
From: "DNS",
|
|
To: s.dohURL,
|
|
Status: log.AccessAccepted,
|
|
Detour: "local",
|
|
})
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
return conn, nil
|
|
},
|
|
}
|
|
s.httpClient = &http.Client{
|
|
Timeout: time.Second * 180,
|
|
Transport: tr,
|
|
}
|
|
errors.LogInfo(context.Background(), "DNS: created Local DOH client for ", url.String())
|
|
return s
|
|
}
|
|
|
|
func baseDOHNameServer(url *url.URL, prefix string, queryStrategy QueryStrategy) *DoHNameServer {
|
|
s := &DoHNameServer{
|
|
ips: make(map[string]*record),
|
|
pub: pubsub.NewService(),
|
|
name: prefix + "//" + url.Host,
|
|
dohURL: url.String(),
|
|
queryStrategy: queryStrategy,
|
|
}
|
|
s.cleanup = &task.Periodic{
|
|
Interval: time.Minute,
|
|
Execute: s.Cleanup,
|
|
}
|
|
return s
|
|
}
|
|
|
|
// Name implements Server.
|
|
func (s *DoHNameServer) Name() string {
|
|
return s.name
|
|
}
|
|
|
|
// Cleanup clears expired items from cache
|
|
func (s *DoHNameServer) 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 *DoHNameServer) 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, len(ipRec.IP))
|
|
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())
|
|
}
|
|
|
|
func (s *DoHNameServer) newReqID() uint16 {
|
|
return uint16(atomic.AddUint32(&s.reqID, 1))
|
|
}
|
|
|
|
func (s *DoHNameServer) sendQuery(ctx context.Context, domain string, clientIP net.IP, option dns_feature.IPOption) {
|
|
errors.LogInfo(ctx, s.name, " querying: ", domain)
|
|
|
|
if s.name+"." == "DOH//"+domain {
|
|
errors.LogError(ctx, s.name, " tries to resolve itself! Use IP or set \"hosts\" instead.")
|
|
return
|
|
}
|
|
|
|
reqs := buildReqMsgs(domain, option, s.newReqID, genEDNS0Options(clientIP))
|
|
|
|
var deadline time.Time
|
|
if d, ok := ctx.Deadline(); ok {
|
|
deadline = d
|
|
} else {
|
|
deadline = time.Now().Add(time.Second * 5)
|
|
}
|
|
|
|
for _, req := range reqs {
|
|
go func(r *dnsRequest) {
|
|
// generate new context for each req, using same context
|
|
// may cause reqs all aborted if any one encounter an error
|
|
dnsCtx := ctx
|
|
|
|
// reserve internal dns server requested Inbound
|
|
if inbound := session.InboundFromContext(ctx); inbound != nil {
|
|
dnsCtx = session.ContextWithInbound(dnsCtx, inbound)
|
|
}
|
|
|
|
dnsCtx = session.ContextWithContent(dnsCtx, &session.Content{
|
|
Protocol: "https",
|
|
SkipDNSResolve: true,
|
|
})
|
|
|
|
// forced to use mux for DOH
|
|
// dnsCtx = session.ContextWithMuxPreferred(dnsCtx, true)
|
|
|
|
var cancel context.CancelFunc
|
|
dnsCtx, cancel = context.WithDeadline(dnsCtx, deadline)
|
|
defer cancel()
|
|
|
|
b, err := dns.PackMessage(r.msg)
|
|
if err != nil {
|
|
errors.LogErrorInner(ctx, err, "failed to pack dns query for ", domain)
|
|
return
|
|
}
|
|
resp, err := s.dohHTTPSContext(dnsCtx, b.Bytes())
|
|
if err != nil {
|
|
errors.LogErrorInner(ctx, err, "failed to retrieve response for ", domain)
|
|
return
|
|
}
|
|
rec, err := parseResponse(resp)
|
|
if err != nil {
|
|
errors.LogErrorInner(ctx, err, "failed to handle DOH response for ", domain)
|
|
return
|
|
}
|
|
s.updateIP(r, rec)
|
|
}(req)
|
|
}
|
|
}
|
|
|
|
func (s *DoHNameServer) dohHTTPSContext(ctx context.Context, b []byte) ([]byte, error) {
|
|
body := bytes.NewBuffer(b)
|
|
req, err := http.NewRequest("POST", s.dohURL, body)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
req.Header.Add("Accept", "application/dns-message")
|
|
req.Header.Add("Content-Type", "application/dns-message")
|
|
|
|
hc := s.httpClient
|
|
|
|
resp, err := hc.Do(req.WithContext(ctx))
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
defer resp.Body.Close()
|
|
if resp.StatusCode != http.StatusOK {
|
|
io.Copy(io.Discard, resp.Body) // flush resp.Body so that the conn is reusable
|
|
return nil, fmt.Errorf("DOH server returned code %d", resp.StatusCode)
|
|
}
|
|
|
|
return io.ReadAll(resp.Body)
|
|
}
|
|
|
|
func (s *DoHNameServer) findIPsForDomain(domain string, option dns_feature.IPOption) ([]net.IP, error) {
|
|
s.RLock()
|
|
record, found := s.ips[domain]
|
|
s.RUnlock()
|
|
|
|
if !found {
|
|
return nil, errRecordNotFound
|
|
}
|
|
|
|
var err4 error
|
|
var err6 error
|
|
var ips []net.Address
|
|
var ip6 []net.Address
|
|
|
|
if option.IPv4Enable {
|
|
ips, err4 = record.A.getIPs()
|
|
}
|
|
|
|
if option.IPv6Enable {
|
|
ip6, err6 = record.AAAA.getIPs()
|
|
ips = append(ips, ip6...)
|
|
}
|
|
|
|
if len(ips) > 0 {
|
|
return toNetIP(ips)
|
|
}
|
|
|
|
if err4 != nil {
|
|
return nil, err4
|
|
}
|
|
|
|
if err6 != nil {
|
|
return nil, err6
|
|
}
|
|
|
|
if (option.IPv4Enable && record.A != nil) || (option.IPv6Enable && record.AAAA != nil) {
|
|
return nil, dns_feature.ErrEmptyResponse
|
|
}
|
|
|
|
return nil, errRecordNotFound
|
|
}
|
|
|
|
// QueryIP implements Server.
|
|
func (s *DoHNameServer) QueryIP(ctx context.Context, domain string, clientIP net.IP, option dns_feature.IPOption, disableCache bool) ([]net.IP, error) { // nolint: dupl
|
|
fqdn := Fqdn(domain)
|
|
option = ResolveIpOptionOverride(s.queryStrategy, option)
|
|
if !option.IPv4Enable && !option.IPv6Enable {
|
|
return nil, dns_feature.ErrEmptyResponse
|
|
}
|
|
|
|
if disableCache {
|
|
errors.LogDebug(ctx, "DNS cache is disabled. Querying IP for ", domain, " at ", s.name)
|
|
} else {
|
|
ips, err := s.findIPsForDomain(fqdn, option)
|
|
if err == nil || err == dns_feature.ErrEmptyResponse {
|
|
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, 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)
|
|
start := time.Now()
|
|
|
|
for {
|
|
ips, 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, err
|
|
}
|
|
|
|
select {
|
|
case <-ctx.Done():
|
|
return nil, ctx.Err()
|
|
case <-done:
|
|
}
|
|
}
|
|
}
|