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Merge pull request #256 from Skimmle/Alpha

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featrue: DoH and DoQ are implemented using AdGuardTeam/dnsProxy
This commit is contained in:
cubemaze 2022-11-12 11:19:04 +08:00 committed by GitHub
commit d78b2b1cfb
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GPG Key ID: 4AEE18F83AFDEB23
6 changed files with 1152 additions and 244 deletions
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27
config/config.go
View File

@ -875,7 +875,7 @@ func hostWithDefaultPort(host string, defPort string) (string, error) {
return net.JoinHostPort(hostname, port), nil
}
func parseNameServer(servers []string) ([]dns.NameServer, error) {
func parseNameServer(servers []string, preferH3 bool) ([]dns.NameServer, error) {
var nameservers []dns.NameServer
for idx, server := range servers {
@ -901,7 +901,15 @@ func parseNameServer(servers []string) ([]dns.NameServer, error) {
addr, err = hostWithDefaultPort(u.Host, "853")
dnsNetType = "tcp-tls" // DNS over TLS
case "https":
clearURL := url.URL{Scheme: "https", Host: u.Host, Path: u.Path}
host := u.Host
if _, _, err := net.SplitHostPort(host); err != nil && strings.Contains(err.Error(), "missing port in address") {
host = net.JoinHostPort(host, "443")
} else {
if err!=nil{
return nil,err
}
}
clearURL := url.URL{Scheme: "https", Host: host, Path: u.Path}
addr = clearURL.String()
dnsNetType = "https" // DNS over HTTPS
if len(u.Fragment) != 0 {
@ -940,17 +948,18 @@ func parseNameServer(servers []string) ([]dns.NameServer, error) {
ProxyAdapter: proxyAdapter,
Interface: dialer.DefaultInterface,
Params: params,
PreferH3: preferH3,
},
)
}
return nameservers, nil
}
func parseNameServerPolicy(nsPolicy map[string]string) (map[string]dns.NameServer, error) {
func parseNameServerPolicy(nsPolicy map[string]string, preferH3 bool) (map[string]dns.NameServer, error) {
policy := map[string]dns.NameServer{}
for domain, server := range nsPolicy {
nameservers, err := parseNameServer([]string{server})
nameservers, err := parseNameServer([]string{server}, preferH3)
if err != nil {
return nil, err
}
@ -1030,26 +1039,26 @@ func parseDNS(rawCfg *RawConfig, hosts *trie.DomainTrie[netip.Addr], rules []C.R
},
}
var err error
if dnsCfg.NameServer, err = parseNameServer(cfg.NameServer); err != nil {
if dnsCfg.NameServer, err = parseNameServer(cfg.NameServer, cfg.PreferH3); err != nil {
return nil, err
}
if dnsCfg.Fallback, err = parseNameServer(cfg.Fallback); err != nil {
if dnsCfg.Fallback, err = parseNameServer(cfg.Fallback, cfg.PreferH3); err != nil {
return nil, err
}
if dnsCfg.NameServerPolicy, err = parseNameServerPolicy(cfg.NameServerPolicy); err != nil {
if dnsCfg.NameServerPolicy, err = parseNameServerPolicy(cfg.NameServerPolicy, cfg.PreferH3); err != nil {
return nil, err
}
if dnsCfg.ProxyServerNameserver, err = parseNameServer(cfg.ProxyServerNameserver); err != nil {
if dnsCfg.ProxyServerNameserver, err = parseNameServer(cfg.ProxyServerNameserver, cfg.PreferH3); err != nil {
return nil, err
}
if len(cfg.DefaultNameserver) == 0 {
return nil, errors.New("default nameserver should have at least one nameserver")
}
if dnsCfg.DefaultNameserver, err = parseNameServer(cfg.DefaultNameserver); err != nil {
if dnsCfg.DefaultNameserver, err = parseNameServer(cfg.DefaultNameserver, cfg.PreferH3); err != nil {
return nil, err
}
// check default nameserver is pure ip addr

11
constant/dns.go
View File

@ -114,3 +114,14 @@ func NewDNSPrefer(prefer string) DNSPrefer {
return DualStack
}
}
type HTTPVersion string
const (
// HTTPVersion11 is HTTP/1.1.
HTTPVersion11 HTTPVersion = "http/1.1"
// HTTPVersion2 is HTTP/2.
HTTPVersion2 HTTPVersion = "h2"
// HTTPVersion3 is HTTP/3.
HTTPVersion3 HTTPVersion = "h3"
)

810
dns/doh.go
View File

@ -1,164 +1,730 @@
package dns
import (
"bytes"
"context"
"crypto/tls"
"encoding/base64"
"errors"
"fmt"
"github.com/Dreamacro/clash/component/dialer"
"github.com/Dreamacro/clash/component/resolver"
tlsC "github.com/Dreamacro/clash/component/tls"
"github.com/lucas-clemente/quic-go"
"github.com/lucas-clemente/quic-go/http3"
D "github.com/miekg/dns"
"io"
"net"
"net/http"
"net/url"
"runtime"
"strconv"
"sync"
"time"
"github.com/Dreamacro/clash/component/dialer"
tlsC "github.com/Dreamacro/clash/component/tls"
C "github.com/Dreamacro/clash/constant"
"github.com/Dreamacro/clash/log"
"github.com/lucas-clemente/quic-go"
"github.com/lucas-clemente/quic-go/http3"
"github.com/miekg/dns"
D "github.com/miekg/dns"
"golang.org/x/net/http2"
)
// Values to configure HTTP and HTTP/2 transport.
const (
// dotMimeType is the DoH mimetype that should be used.
dotMimeType = "application/dns-message"
// transportDefaultReadIdleTimeout is the default timeout for pinging
// idle connections in HTTP/2 transport.
transportDefaultReadIdleTimeout = 30 * time.Second
// transportDefaultIdleConnTimeout is the default timeout for idle
// connections in HTTP transport.
transportDefaultIdleConnTimeout = 5 * time.Minute
// dohMaxConnsPerHost controls the maximum number of connections for
// each host.
dohMaxConnsPerHost = 1
dialTimeout = 10 * time.Second
// dohMaxIdleConns controls the maximum number of connections being idle
// at the same time.
dohMaxIdleConns = 1
maxElapsedTime = time.Second * 30
)
type dohClient struct {
url string
transport http.RoundTripper
var DefaultHTTPVersions = []C.HTTPVersion{C.HTTPVersion11, C.HTTPVersion2}
// dnsOverHTTPS is a struct that implements the Upstream interface for the
// DNS-over-HTTPS protocol.
type dnsOverHTTPS struct {
// The Client's Transport typically has internal state (cached TCP
// connections), so Clients should be reused instead of created as
// needed. Clients are safe for concurrent use by multiple goroutines.
client *http.Client
clientMu sync.Mutex
// quicConfig is the QUIC configuration that is used if HTTP/3 is enabled
// for this upstream.
quicConfig *quic.Config
quicConfigGuard sync.Mutex
url *url.URL
r *Resolver
httpVersions []C.HTTPVersion
proxyAdapter string
}
func (dc *dohClient) Exchange(m *D.Msg) (msg *D.Msg, err error) {
return dc.ExchangeContext(context.Background(), m)
// type check
var _ dnsClient = (*dnsOverHTTPS)(nil)
// newDoH returns the DNS-over-HTTPS Upstream.
func newDoHClient(urlString string, r *Resolver, preferH3 bool, params map[string]string, proxyAdapter string) dnsClient {
u, _ := url.Parse(urlString)
httpVersions := DefaultHTTPVersions
if preferH3 {
httpVersions = append(httpVersions, C.HTTPVersion3)
}
if params["h3"] == "true" {
httpVersions = []C.HTTPVersion{C.HTTPVersion3}
}
doh := &dnsOverHTTPS{
url: u,
r: r,
quicConfig: &quic.Config{
KeepAlivePeriod: QUICKeepAlivePeriod,
TokenStore: newQUICTokenStore(),
},
httpVersions: httpVersions,
}
runtime.SetFinalizer(doh, (*dnsOverHTTPS).Close)
return doh
}
func (dc *dohClient) ExchangeContext(ctx context.Context, m *D.Msg) (msg *D.Msg, err error) {
// https://datatracker.ietf.org/doc/html/rfc8484#section-4.1
// In order to maximize cache friendliness, SHOULD use a DNS ID of 0 in every DNS request.
newM := *m
newM.Id = 0
req, err := dc.newRequest(&newM)
// Address implements the Upstream interface for *dnsOverHTTPS.
func (p *dnsOverHTTPS) Address() string { return p.url.String() }
func (p *dnsOverHTTPS) ExchangeContext(ctx context.Context, m *D.Msg) (msg *D.Msg, err error) {
// Quote from https://www.rfc-editor.org/rfc/rfc8484.html:
// In order to maximize HTTP cache friendliness, DoH clients using media
// formats that include the ID field from the DNS message header, such
// as "application/dns-message", SHOULD use a DNS ID of 0 in every DNS
// request.
id := m.Id
m.Id = 0
defer func() {
// Restore the original ID to not break compatibility with proxies.
m.Id = id
if msg != nil {
msg.Id = id
}
}()
// Check if there was already an active client before sending the request.
// We'll only attempt to re-connect if there was one.
client, isCached, err := p.getClient()
if err != nil {
return nil, err
return nil, fmt.Errorf("failed to init http client: %w", err)
}
req = req.WithContext(ctx)
msg, err = dc.doRequest(req)
if err == nil {
msg.Id = m.Id
}
return
}
// Make the first attempt to send the DNS query.
msg, err = p.exchangeHTTPS(ctx, client, m)
// Make up to 2 attempts to re-create the HTTP client and send the request
// again. There are several cases (mostly, with QUIC) where this workaround
// is necessary to make HTTP client usable. We need to make 2 attempts in
// the case when the connection was closed (due to inactivity for example)
// AND the server refuses to open a 0-RTT connection.
for i := 0; isCached && p.shouldRetry(err) && i < 2; i++ {
client, err = p.resetClient(err)
if err != nil {
return nil, fmt.Errorf("failed to reset http client: %w", err)
}
msg, err = p.exchangeHTTPS(ctx, client, m)
}
// newRequest returns a new DoH request given a dns.Msg.
func (dc *dohClient) newRequest(m *D.Msg) (*http.Request, error) {
buf, err := m.Pack()
if err != nil {
return nil, err
// If the request failed anyway, make sure we don't use this client.
_, resErr := p.resetClient(err)
return nil, fmt.Errorf("err:%v,resErr:%v", err, resErr)
}
req, err := http.NewRequest(http.MethodPost, dc.url, bytes.NewReader(buf))
if err != nil {
return req, err
}
req.Header.Set("content-type", dotMimeType)
req.Header.Set("accept", dotMimeType)
return req, nil
}
func (dc *dohClient) doRequest(req *http.Request) (msg *D.Msg, err error) {
client := &http.Client{Transport: dc.transport}
resp, err := client.Do(req)
if err != nil {
return nil, err
}
defer resp.Body.Close()
buf, err := io.ReadAll(resp.Body)
if err != nil {
return nil, err
}
msg = &D.Msg{}
err = msg.Unpack(buf)
return msg, err
}
func newDoHClient(url string, r *Resolver, params map[string]string, proxyAdapter string) *dohClient {
useH3 := params["h3"] == "true"
TLCConfig := tlsC.GetDefaultTLSConfig()
var transport http.RoundTripper
if useH3 {
transport = &http3.RoundTripper{
Dial: func(ctx context.Context, addr string, tlsCfg *tls.Config, cfg *quic.Config) (quic.EarlyConnection, error) {
host, port, err := net.SplitHostPort(addr)
if err != nil {
return nil, err
}
// Exchange implements the Upstream interface for *dnsOverHTTPS.
func (p *dnsOverHTTPS) Exchange(m *dns.Msg) (*dns.Msg, error) {
return p.ExchangeContext(context.Background(), m)
}
ip, err := resolver.ResolveIPWithResolver(host, r)
if err != nil {
return nil, err
}
// Close implements the Upstream interface for *dnsOverHTTPS.
func (p *dnsOverHTTPS) Close() (err error) {
p.clientMu.Lock()
defer p.clientMu.Unlock()
portInt, err := strconv.Atoi(port)
if err != nil {
return nil, err
}
runtime.SetFinalizer(p, nil)
udpAddr := net.UDPAddr{
IP: net.ParseIP(ip.String()),
Port: portInt,
}
if p.client == nil {
return nil
}
var conn net.PacketConn
if proxyAdapter == "" {
conn, err = dialer.ListenPacket(ctx, "udp", "")
if err != nil {
return nil, err
}
} else {
if wrapConn, err := dialContextExtra(ctx, proxyAdapter, "udp", ip, port); err == nil {
if pc, ok := wrapConn.(*wrapPacketConn); ok {
conn = pc
} else {
return nil, fmt.Errorf("conn isn't wrapPacketConn")
}
} else {
return nil, err
}
}
return p.closeClient(p.client)
}
return quic.DialEarlyContext(ctx, conn, &udpAddr, host, tlsCfg, cfg)
},
TLSClientConfig: TLCConfig,
// closeClient cleans up resources used by client if necessary. Note, that at
// this point it should only be done for HTTP/3 as it may leak due to keep-alive
// connections.
func (p *dnsOverHTTPS) closeClient(client *http.Client) (err error) {
if isHTTP3(client) {
return client.Transport.(io.Closer).Close()
}
return nil
}
// exchangeHTTPS logs the request and its result and calls exchangeHTTPSClient.
func (p *dnsOverHTTPS) exchangeHTTPS(ctx context.Context, client *http.Client, req *dns.Msg) (resp *dns.Msg, err error) {
resp, err = p.exchangeHTTPSClient(ctx, client, req)
return resp, err
}
// exchangeHTTPSClient sends the DNS query to a DoH resolver using the specified
// http.Client instance.
func (p *dnsOverHTTPS) exchangeHTTPSClient(
ctx context.Context,
client *http.Client,
req *dns.Msg,
) (resp *dns.Msg, err error) {
buf, err := req.Pack()
if err != nil {
return nil, fmt.Errorf("packing message: %w", err)
}
// It appears, that GET requests are more memory-efficient with Golang
// implementation of HTTP/2.
method := http.MethodGet
if isHTTP3(client) {
// If we're using HTTP/3, use http3.MethodGet0RTT to force using 0-RTT.
method = http3.MethodGet0RTT
}
p.url.RawQuery = fmt.Sprintf("dns=%s", base64.RawURLEncoding.EncodeToString(buf))
httpReq, err := http.NewRequest(method, p.url.String(), nil)
if err != nil {
return nil, fmt.Errorf("creating http request to %s: %w", p.url, err)
}
httpReq.Header.Set("Accept", "application/dns-message")
httpReq.Header.Set("User-Agent", "")
_ = httpReq.WithContext(ctx)
httpResp, err := client.Do(httpReq)
if err != nil {
return nil, fmt.Errorf("requesting %s: %w", p.url, err)
}
defer httpResp.Body.Close()
body, err := io.ReadAll(httpResp.Body)
if err != nil {
return nil, fmt.Errorf("reading %s: %w", p.url, err)
}
if httpResp.StatusCode != http.StatusOK {
return nil,
fmt.Errorf(
"expected status %d, got %d from %s",
http.StatusOK,
httpResp.StatusCode,
p.url,
)
}
resp = &dns.Msg{}
err = resp.Unpack(body)
if err != nil {
return nil, fmt.Errorf(
"unpacking response from %s: body is %s: %w",
p.url,
body,
err,
)
}
if resp.Id != req.Id {
err = dns.ErrId
}
return resp, err
}
// shouldRetry checks what error we have received and returns true if we should
// re-create the HTTP client and retry the request.
func (p *dnsOverHTTPS) shouldRetry(err error) (ok bool) {
if err == nil {
return false
}
var netErr net.Error
if errors.As(err, &netErr) && netErr.Timeout() {
// If this is a timeout error, trying to forcibly re-create the HTTP
// client instance. This is an attempt to fix an issue with DoH client
// stalling after a network change.
//
// See https://github.com/AdguardTeam/AdGuardHome/issues/3217.
return true
}
if isQUICRetryError(err) {
return true
}
return false
}
// resetClient triggers re-creation of the *http.Client that is used by this
// upstream. This method accepts the error that caused resetting client as
// depending on the error we may also reset the QUIC config.
func (p *dnsOverHTTPS) resetClient(resetErr error) (client *http.Client, err error) {
p.clientMu.Lock()
defer p.clientMu.Unlock()
if errors.Is(resetErr, quic.Err0RTTRejected) {
// Reset the TokenStore only if 0-RTT was rejected.
p.resetQUICConfig()
}
oldClient := p.client
if oldClient != nil {
closeErr := p.closeClient(oldClient)
if closeErr != nil {
log.Warnln("warning: failed to close the old http client: %v", closeErr)
}
}
log.Debugln("re-creating the http client due to %v", resetErr)
p.client, err = p.createClient()
return p.client, err
}
// getQUICConfig returns the QUIC config in a thread-safe manner. Note, that
// this method returns a pointer, it is forbidden to change its properties.
func (p *dnsOverHTTPS) getQUICConfig() (c *quic.Config) {
p.quicConfigGuard.Lock()
defer p.quicConfigGuard.Unlock()
return p.quicConfig
}
// resetQUICConfig Re-create the token store to make sure we're not trying to
// use invalid for 0-RTT.
func (p *dnsOverHTTPS) resetQUICConfig() {
p.quicConfigGuard.Lock()
defer p.quicConfigGuard.Unlock()
p.quicConfig = p.quicConfig.Clone()
p.quicConfig.TokenStore = newQUICTokenStore()
}
// getClient gets or lazily initializes an HTTP client (and transport) that will
// be used for this DoH resolver.
func (p *dnsOverHTTPS) getClient() (c *http.Client, isCached bool, err error) {
startTime := time.Now()
p.clientMu.Lock()
defer p.clientMu.Unlock()
if p.client != nil {
return p.client, true, nil
}
// Timeout can be exceeded while waiting for the lock. This happens quite
// often on mobile devices.
elapsed := time.Since(startTime)
if elapsed > maxElapsedTime {
return nil, false, fmt.Errorf("timeout exceeded: %s", elapsed)
}
log.Debugln("creating a new http client")
p.client, err = p.createClient()
return p.client, false, err
}
// createClient creates a new *http.Client instance. The HTTP protocol version
// will depend on whether HTTP3 is allowed and provided by this upstream. Note,
// that we'll attempt to establish a QUIC connection when creating the client in
// order to check whether HTTP3 is supported.
func (p *dnsOverHTTPS) createClient() (*http.Client, error) {
transport, err := p.createTransport()
if err != nil {
return nil, fmt.Errorf("initializing http transport: %w", err)
}
client := &http.Client{
Transport: transport,
Timeout: DefaultTimeout,
Jar: nil,
}
p.client = client
return p.client, nil
}
// createTransport initializes an HTTP transport that will be used specifically
// for this DoH resolver. This HTTP transport ensures that the HTTP requests
// will be sent exactly to the IP address got from the bootstrap resolver. Note,
// that this function will first attempt to establish a QUIC connection (if
// HTTP3 is enabled in the upstream options). If this attempt is successful,
// it returns an HTTP3 transport, otherwise it returns the H1/H2 transport.
func (p *dnsOverHTTPS) createTransport() (t http.RoundTripper, err error) {
tlsConfig := tlsC.GetGlobalFingerprintTLCConfig(
&tls.Config{
InsecureSkipVerify: false,
MinVersion: tls.VersionTLS12,
SessionTicketsDisabled: false,
})
var nextProtos []string
for _, v := range p.httpVersions {
nextProtos = append(nextProtos, string(v))
}
tlsConfig.NextProtos = nextProtos
dialContext := getDialHandler(p.r, p.proxyAdapter)
// First, we attempt to create an HTTP3 transport. If the probe QUIC
// connection is established successfully, we'll be using HTTP3 for this
// upstream.
transportH3, err := p.createTransportH3(tlsConfig, dialContext)
if err == nil {
log.Debugln("using HTTP/3 for this upstream: QUIC was faster")
return transportH3, nil
}
log.Debugln("using HTTP/2 for this upstream: %v", err)
if !p.supportsHTTP() {
return nil, errors.New("HTTP1/1 and HTTP2 are not supported by this upstream")
}
transport := &http.Transport{
TLSClientConfig: tlsConfig,
DisableCompression: true,
DialContext: dialContext,
IdleConnTimeout: transportDefaultIdleConnTimeout,
MaxConnsPerHost: dohMaxConnsPerHost,
MaxIdleConns: dohMaxIdleConns,
// Since we have a custom DialContext, we need to use this field to
// make golang http.Client attempt to use HTTP/2. Otherwise, it would
// only be used when negotiated on the TLS level.
ForceAttemptHTTP2: true,
}
// Explicitly configure transport to use HTTP/2.
//
// See https://github.com/AdguardTeam/dnsproxy/issues/11.
var transportH2 *http2.Transport
transportH2, err = http2.ConfigureTransports(transport)
if err != nil {
return nil, err
}
// Enable HTTP/2 pings on idle connections.
transportH2.ReadIdleTimeout = transportDefaultReadIdleTimeout
return transport, nil
}
// http3Transport is a wrapper over *http3.RoundTripper that tries to optimize
// its behavior. The main thing that it does is trying to force use a single
// connection to a host instead of creating a new one all the time. It also
// helps mitigate race issues with quic-go.
type http3Transport struct {
baseTransport *http3.RoundTripper
closed bool
mu sync.RWMutex
}
// type check
var _ http.RoundTripper = (*http3Transport)(nil)
// RoundTrip implements the http.RoundTripper interface for *http3Transport.
func (h *http3Transport) RoundTrip(req *http.Request) (resp *http.Response, err error) {
h.mu.RLock()
defer h.mu.RUnlock()
if h.closed {
return nil, net.ErrClosed
}
// Try to use cached connection to the target host if it's available.
resp, err = h.baseTransport.RoundTripOpt(req, http3.RoundTripOpt{OnlyCachedConn: true})
if errors.Is(err, http3.ErrNoCachedConn) {
// If there are no cached connection, trigger creating a new one.
resp, err = h.baseTransport.RoundTrip(req)
}
return resp, err
}
// type check
var _ io.Closer = (*http3Transport)(nil)
// Close implements the io.Closer interface for *http3Transport.
func (h *http3Transport) Close() (err error) {
h.mu.Lock()
defer h.mu.Unlock()
h.closed = true
return h.baseTransport.Close()
}
// createTransportH3 tries to create an HTTP/3 transport for this upstream.
// We should be able to fall back to H1/H2 in case if HTTP/3 is unavailable or
// if it is too slow. In order to do that, this method will run two probes
// in parallel (one for TLS, the other one for QUIC) and if QUIC is faster it
// will create the *http3.RoundTripper instance.
func (doh *dnsOverHTTPS) createTransportH3(
tlsConfig *tls.Config,
dialContext dialHandler,
) (roundTripper http.RoundTripper, err error) {
if !doh.supportsH3() {
return nil, errors.New("HTTP3 support is not enabled")
}
addr, err := doh.probeH3(tlsConfig, dialContext)
if err != nil {
return nil, err
}
rt := &http3.RoundTripper{
Dial: func(
ctx context.Context,
// Ignore the address and always connect to the one that we got
// from the bootstrapper.
_ string,
tlsCfg *tls.Config,
cfg *quic.Config,
) (c quic.EarlyConnection, err error) {
return doh.dialQuic(ctx, addr, tlsCfg, cfg)
},
DisableCompression: true,
TLSClientConfig: tlsConfig,
QuicConfig: doh.getQUICConfig(),
}
return &http3Transport{baseTransport: rt}, nil
}
func (doh *dnsOverHTTPS) dialQuic(ctx context.Context, addr string, tlsCfg *tls.Config, cfg *quic.Config) (quic.EarlyConnection, error) {
ip, port, err := net.SplitHostPort(addr)
if err != nil {
return nil, err
}
portInt, err := strconv.Atoi(port)
if err != nil {
return nil, err
}
udpAddr := net.UDPAddr{
IP: net.ParseIP(ip),
Port: portInt,
}
var conn net.PacketConn
if doh.proxyAdapter == "" {
conn, err = dialer.ListenPacket(ctx, "udp", "")
if err != nil {
return nil, err
}
} else {
transport = &http.Transport{
ForceAttemptHTTP2: true,
DialContext: func(ctx context.Context, network, addr string) (net.Conn, error) {
host, port, err := net.SplitHostPort(addr)
if err != nil {
return nil, err
}
if wrapConn, err := dialContextExtra(ctx, doh.proxyAdapter, "udp", udpAddr.AddrPort().Addr(), port); err == nil {
if pc, ok := wrapConn.(*wrapPacketConn); ok {
conn = pc
} else {
return nil, fmt.Errorf("conn isn't wrapPacketConn")
}
} else {
return nil, err
}
}
return quic.DialEarlyContext(ctx, conn, &udpAddr, doh.url.Host, tlsCfg, cfg)
}
ip, err := resolver.ResolveIPWithResolver(host, r)
if err != nil {
return nil, err
}
// probeH3 runs a test to check whether QUIC is faster than TLS for this
// upstream. If the test is successful it will return the address that we
// should use to establish the QUIC connections.
func (p *dnsOverHTTPS) probeH3(
tlsConfig *tls.Config,
dialContext dialHandler,
) (addr string, err error) {
// We're using bootstrapped address instead of what's passed to the function
// it does not create an actual connection, but it helps us determine
// what IP is actually reachable (when there are v4/v6 addresses).
rawConn, err := dialContext(context.Background(), "udp", p.url.Host)
if err != nil {
return "", fmt.Errorf("failed to dial: %w", err)
}
// It's never actually used.
_ = rawConn.Close()
if proxyAdapter == "" {
return dialer.DialContext(ctx, "tcp", net.JoinHostPort(ip.String(), port))
} else {
return dialContextExtra(ctx, proxyAdapter, "tcp", ip, port)
}
},
TLSClientConfig: TLCConfig,
udpConn, ok := rawConn.(*net.UDPConn)
if !ok {
return "", fmt.Errorf("not a UDP connection to %s", p.Address())
}
addr = udpConn.RemoteAddr().String()
// Avoid spending time on probing if this upstream only supports HTTP/3.
if p.supportsH3() && !p.supportsHTTP() {
return addr, nil
}
// Use a new *tls.Config with empty session cache for probe connections.
// Surprisingly, this is really important since otherwise it invalidates
// the existing cache.
// TODO(ameshkov): figure out why the sessions cache invalidates here.
probeTLSCfg := tlsConfig.Clone()
probeTLSCfg.ClientSessionCache = nil
// Do not expose probe connections to the callbacks that are passed to
// the bootstrap options to avoid side-effects.
// TODO(ameshkov): consider exposing, somehow mark that this is a probe.
probeTLSCfg.VerifyPeerCertificate = nil
probeTLSCfg.VerifyConnection = nil
// Run probeQUIC and probeTLS in parallel and see which one is faster.
chQuic := make(chan error, 1)
chTLS := make(chan error, 1)
go p.probeQUIC(addr, probeTLSCfg, chQuic)
go p.probeTLS(dialContext, probeTLSCfg, chTLS)
select {
case quicErr := <-chQuic:
if quicErr != nil {
// QUIC failed, return error since HTTP3 was not preferred.
return "", quicErr
}
// Return immediately, QUIC was faster.
return addr, quicErr
case tlsErr := <-chTLS:
if tlsErr != nil {
// Return immediately, TLS failed.
log.Debugln("probing TLS: %v", tlsErr)
return addr, nil
}
return "", errors.New("TLS was faster than QUIC, prefer it")
}
}
// probeQUIC attempts to establish a QUIC connection to the specified address.
// We run probeQUIC and probeTLS in parallel and see which one is faster.
func (p *dnsOverHTTPS) probeQUIC(addr string, tlsConfig *tls.Config, ch chan error) {
startTime := time.Now()
timeout := DefaultTimeout
ctx, cancel := context.WithDeadline(context.Background(), time.Now().Add(timeout))
defer cancel()
conn, err := p.dialQuic(ctx, addr, tlsConfig, p.getQUICConfig())
if err != nil {
ch <- fmt.Errorf("opening QUIC connection to %s: %w", p.Address(), err)
return
}
// Ignore the error since there's no way we can use it for anything useful.
_ = conn.CloseWithError(QUICCodeNoError, "")
ch <- nil
elapsed := time.Now().Sub(startTime)
log.Debugln("elapsed on establishing a QUIC connection: %s", elapsed)
}
// probeTLS attempts to establish a TLS connection to the specified address. We
// run probeQUIC and probeTLS in parallel and see which one is faster.
func (p *dnsOverHTTPS) probeTLS(dialContext dialHandler, tlsConfig *tls.Config, ch chan error) {
startTime := time.Now()
conn, err := p.tlsDial(dialContext, "tcp", tlsConfig)
if err != nil {
ch <- fmt.Errorf("opening TLS connection: %w", err)
return
}
// Ignore the error since there's no way we can use it for anything useful.
_ = conn.Close()
ch <- nil
elapsed := time.Now().Sub(startTime)
log.Debugln("elapsed on establishing a TLS connection: %s", elapsed)
}
// supportsH3 returns true if HTTP/3 is supported by this upstream.
func (p *dnsOverHTTPS) supportsH3() (ok bool) {
for _, v := range p.supportedHTTPVersions() {
if v == C.HTTPVersion3 {
return true
}
}
return &dohClient{
url: url,
transport: transport,
}
return false
}
// supportsHTTP returns true if HTTP/1.1 or HTTP2 is supported by this upstream.
func (p *dnsOverHTTPS) supportsHTTP() (ok bool) {
for _, v := range p.supportedHTTPVersions() {
if v == C.HTTPVersion11 || v == C.HTTPVersion2 {
return true
}
}
return false
}
// supportedHTTPVersions returns the list of supported HTTP versions.
func (p *dnsOverHTTPS) supportedHTTPVersions() (v []C.HTTPVersion) {
v = p.httpVersions
if v == nil {
v = DefaultHTTPVersions
}
return v
}
// isHTTP3 checks if the *http.Client is an HTTP/3 client.
func isHTTP3(client *http.Client) (ok bool) {
_, ok = client.Transport.(*http3Transport)
return ok
}
// tlsDial is basically the same as tls.DialWithDialer, but we will call our own
// dialContext function to get connection.
func (doh *dnsOverHTTPS) tlsDial(dialContext dialHandler, network string, config *tls.Config) (*tls.Conn, error) {
// We're using bootstrapped address instead of what's passed
// to the function.
rawConn, err := dialContext(context.Background(), network, doh.url.Host)
if err != nil {
return nil, err
}
// We want the timeout to cover the whole process: TCP connection and
// TLS handshake dialTimeout will be used as connection deadLine.
conn := tls.Client(rawConn, config)
err = conn.SetDeadline(time.Now().Add(dialTimeout))
if err != nil {
// Must not happen in normal circumstances.
panic(fmt.Errorf("cannot set deadline: %w", err))
}
err = conn.Handshake()
if err != nil {
defer conn.Close()
return nil, err
}
return conn, nil
}

535
dns/doq.go
View File

@ -1,134 +1,307 @@
package dns
import (
"bytes"
"context"
"crypto/tls"
"encoding/binary"
"errors"
"fmt"
"github.com/Dreamacro/clash/component/dialer"
"github.com/Dreamacro/clash/component/resolver"
tlsC "github.com/Dreamacro/clash/component/tls"
"github.com/lucas-clemente/quic-go"
"net"
"net/netip"
"runtime"
"strconv"
"sync"
"time"
"github.com/Dreamacro/clash/component/dialer"
tlsC "github.com/Dreamacro/clash/component/tls"
"github.com/lucas-clemente/quic-go"
"github.com/Dreamacro/clash/log"
D "github.com/miekg/dns"
)
const NextProtoDQ = "doq"
const (
// QUICCodeNoError is used when the connection or stream needs to be closed,
// but there is no error to signal.
QUICCodeNoError = quic.ApplicationErrorCode(0)
// QUICCodeInternalError signals that the DoQ implementation encountered
// an internal error and is incapable of pursuing the transaction or the
// connection.
QUICCodeInternalError = quic.ApplicationErrorCode(1)
// QUICKeepAlivePeriod is the value that we pass to *quic.Config and that
// controls the period with with keep-alive frames are being sent to the
// connection. We set it to 20s as it would be in the quic-go@v0.27.1 with
// KeepAlive field set to true This value is specified in
// https://pkg.go.dev/github.com/lucas-clemente/quic-go/internal/protocol#MaxKeepAliveInterval.
//
// TODO(ameshkov): Consider making it configurable.
QUICKeepAlivePeriod = time.Second * 20
DefaultTimeout = time.Second * 5
)
var bytesPool = sync.Pool{New: func() interface{} { return &bytes.Buffer{} }}
type dialHandler func(ctx context.Context, network, addr string) (net.Conn, error)
// dnsOverQUIC is a struct that implements the Upstream interface for the
// DNS-over-QUIC protocol (spec: https://www.rfc-editor.org/rfc/rfc9250.html).
type dnsOverQUIC struct {
// quicConfig is the QUIC configuration that is used for establishing
// connections to the upstream. This configuration includes the TokenStore
// that needs to be stored for the lifetime of dnsOverQUIC since we can
// re-create the connection.
quicConfig *quic.Config
quicConfigGuard sync.Mutex
// conn is the current active QUIC connection. It can be closed and
// re-opened when needed.
conn quic.Connection
connMu sync.RWMutex
// bytesPool is a *sync.Pool we use to store byte buffers in. These byte
// buffers are used to read responses from the upstream.
bytesPool *sync.Pool
bytesPoolGuard sync.Mutex
type quicClient struct {
addr string
r *Resolver
connection quic.Connection
proxyAdapter string
udp net.PacketConn
sync.RWMutex // protects connection and bytesPool
r *Resolver
}
func newDOQ(r *Resolver, addr, proxyAdapter string) *quicClient {
return &quicClient{
// type check
var _ dnsClient = (*dnsOverQUIC)(nil)
// newDoQ returns the DNS-over-QUIC Upstream.
func newDoQ(resolver *Resolver, addr string, adapter string) (dnsClient, error) {
doq := &dnsOverQUIC{
addr: addr,
r: r,
proxyAdapter: proxyAdapter,
proxyAdapter: adapter,
r: resolver,
quicConfig: &quic.Config{
KeepAlivePeriod: QUICKeepAlivePeriod,
TokenStore: newQUICTokenStore(),
},
}
runtime.SetFinalizer(doq, (*dnsOverQUIC).Close)
return doq, nil
}
func (dc *quicClient) Exchange(m *D.Msg) (msg *D.Msg, err error) {
return dc.ExchangeContext(context.Background(), m)
}
// Address implements the Upstream interface for *dnsOverQUIC.
func (p *dnsOverQUIC) Address() string { return p.addr }
func (p *dnsOverQUIC) ExchangeContext(ctx context.Context, m *D.Msg) (msg *D.Msg, err error) {
// When sending queries over a QUIC connection, the DNS Message ID MUST be
// set to zero.
id := m.Id
m.Id = 0
defer func() {
// Restore the original ID to not break compatibility with proxies.
m.Id = id
if msg != nil {
msg.Id = id
}
}()
// Check if there was already an active conn before sending the request.
// We'll only attempt to re-connect if there was one.
hasConnection := p.hasConnection()
// Make the first attempt to send the DNS query.
msg, err = p.exchangeQUIC(ctx, m)
// Make up to 2 attempts to re-open the QUIC connection and send the request
// again. There are several cases where this workaround is necessary to
// make DoQ usable. We need to make 2 attempts in the case when the
// connection was closed (due to inactivity for example) AND the server
// refuses to open a 0-RTT connection.
for i := 0; hasConnection && p.shouldRetry(err) && i < 2; i++ {
log.Debugln("re-creating the QUIC connection and retrying due to %v", err)
// Close the active connection to make sure we'll try to re-connect.
p.closeConnWithError(err)
// Retry sending the request.
msg, err = p.exchangeQUIC(ctx, m)
}
func (dc *quicClient) ExchangeContext(ctx context.Context, m *D.Msg) (msg *D.Msg, err error) {
stream, err := dc.openStream(ctx)
if err != nil {
return nil, fmt.Errorf("failed to open new stream to %s", dc.addr)
// If we're unable to exchange messages, make sure the connection is
// closed and signal about an internal error.
p.closeConnWithError(err)
}
buf, err := m.Pack()
return msg, err
}
// Exchange implements the Upstream interface for *dnsOverQUIC.
func (p *dnsOverQUIC) Exchange(m *D.Msg) (msg *D.Msg, err error) {
return p.ExchangeContext(context.Background(), m)
}
// Close implements the Upstream interface for *dnsOverQUIC.
func (p *dnsOverQUIC) Close() (err error) {
p.connMu.Lock()
defer p.connMu.Unlock()
runtime.SetFinalizer(p, nil)
if p.conn != nil {
err = p.conn.CloseWithError(QUICCodeNoError, "")
}
return err
}
// exchangeQUIC attempts to open a QUIC connection, send the DNS message
// through it and return the response it got from the server.
func (p *dnsOverQUIC) exchangeQUIC(ctx context.Context, msg *D.Msg) (resp *D.Msg, err error) {
var conn quic.Connection
conn, err = p.getConnection(true)
if err != nil {
return nil, err
}
_, err = stream.Write(buf)
var buf []byte
buf, err = msg.Pack()
if err != nil {
return nil, fmt.Errorf("failed to pack DNS message for DoQ: %w", err)
}
var stream quic.Stream
stream, err = p.openStream(ctx, conn)
if err != nil {
return nil, err
}
_, err = stream.Write(AddPrefix(buf))
if err != nil {
return nil, fmt.Errorf("failed to write to a QUIC stream: %w", err)
}
// The client MUST send the DNS query over the selected stream, and MUST
// indicate through the STREAM FIN mechanism that no further data will
// be sent on that stream.
// stream.Close() -- closes the write-direction of the stream.
// be sent on that stream. Note, that stream.Close() closes the
// write-direction of the stream, but does not prevent reading from it.
_ = stream.Close()
respBuf := bytesPool.Get().(*bytes.Buffer)
defer bytesPool.Put(respBuf)
defer respBuf.Reset()
n, err := respBuf.ReadFrom(stream)
if err != nil && n == 0 {
return nil, err
}
reply := new(D.Msg)
err = reply.Unpack(respBuf.Bytes())
if err != nil {
return nil, err
}
return reply, nil
return p.readMsg(stream)
}
func isActive(s quic.Connection) bool {
select {
case <-s.Context().Done():
return false
default:
return true
}
// AddPrefix adds a 2-byte prefix with the DNS message length.
func AddPrefix(b []byte) (m []byte) {
m = make([]byte, 2+len(b))
binary.BigEndian.PutUint16(m, uint16(len(b)))
copy(m[2:], b)
return m
}
// getConnection - opens or returns an existing quic.Connection
// useCached - if true and cached connection exists, return it right away
// otherwise - forcibly creates a new connection
func (dc *quicClient) getConnection(ctx context.Context) (quic.Connection, error) {
var connection quic.Connection
dc.RLock()
connection = dc.connection
// shouldRetry checks what error we received and decides whether it is required
// to re-open the connection and retry sending the request.
func (p *dnsOverQUIC) shouldRetry(err error) (ok bool) {
return isQUICRetryError(err)
}
if connection != nil && isActive(connection) {
dc.RUnlock()
return connection, nil
}
// getBytesPool returns (creates if needed) a pool we store byte buffers in.
func (p *dnsOverQUIC) getBytesPool() (pool *sync.Pool) {
p.bytesPoolGuard.Lock()
defer p.bytesPoolGuard.Unlock()
dc.RUnlock()
if p.bytesPool == nil {
p.bytesPool = &sync.Pool{
New: func() interface{} {
b := make([]byte, MaxMsgSize)
dc.Lock()
defer dc.Unlock()
connection = dc.connection
if connection != nil {
if isActive(connection) {
return connection, nil
} else {
_ = connection.CloseWithError(quic.ApplicationErrorCode(0), "")
return &b
},
}
}
var err error
connection, err = dc.openConnection(ctx)
dc.connection = connection
return connection, err
return p.bytesPool
}
func (dc *quicClient) openConnection(ctx context.Context) (quic.Connection, error) {
if dc.udp != nil {
_ = dc.udp.Close()
// getConnection opens or returns an existing quic.Connection. useCached
// argument controls whether we should try to use the existing cached
// connection. If it is false, we will forcibly create a new connection and
// close the existing one if needed.
func (p *dnsOverQUIC) getConnection(useCached bool) (quic.Connection, error) {
var conn quic.Connection
p.connMu.RLock()
conn = p.conn
if conn != nil && useCached {
p.connMu.RUnlock()
return conn, nil
}
if conn != nil {
// we're recreating the connection, let's create a new one.
_ = conn.CloseWithError(QUICCodeNoError, "")
}
p.connMu.RUnlock()
p.connMu.Lock()
defer p.connMu.Unlock()
var err error
conn, err = p.openConnection()
if err != nil {
return nil, err
}
p.conn = conn
return conn, nil
}
// hasConnection returns true if there's an active QUIC connection.
func (p *dnsOverQUIC) hasConnection() (ok bool) {
p.connMu.Lock()
defer p.connMu.Unlock()
return p.conn != nil
}
// getQUICConfig returns the QUIC config in a thread-safe manner. Note, that
// this method returns a pointer, it is forbidden to change its properties.
func (p *dnsOverQUIC) getQUICConfig() (c *quic.Config) {
p.quicConfigGuard.Lock()
defer p.quicConfigGuard.Unlock()
return p.quicConfig
}
// resetQUICConfig re-creates the tokens store as we may need to use a new one
// if we failed to connect.
func (p *dnsOverQUIC) resetQUICConfig() {
p.quicConfigGuard.Lock()
defer p.quicConfigGuard.Unlock()
p.quicConfig = p.quicConfig.Clone()
p.quicConfig.TokenStore = newQUICTokenStore()
}
// openStream opens a new QUIC stream for the specified connection.
func (p *dnsOverQUIC) openStream(ctx context.Context, conn quic.Connection) (quic.Stream, error) {
ctx, cancel := context.WithCancel(ctx)
defer cancel()
stream, err := conn.OpenStreamSync(ctx)
if err == nil {
return stream, nil
}
// We can get here if the old QUIC connection is not valid anymore. We
// should try to re-create the connection again in this case.
newConn, err := p.getConnection(false)
if err != nil {
return nil, err
}
// Open a new stream.
return newConn.OpenStreamSync(ctx)
}
// openConnection opens a new QUIC connection.
func (doq *dnsOverQUIC) openConnection() (conn quic.Connection, err error) {
tlsConfig := tlsC.GetGlobalFingerprintTLCConfig(
&tls.Config{
InsecureSkipVerify: false,
@ -137,42 +310,45 @@ func (dc *quicClient) openConnection(ctx context.Context) (quic.Connection, erro
},
SessionTicketsDisabled: false,
})
quicConfig := &quic.Config{
ConnectionIDLength: 12,
HandshakeIdleTimeout: time.Second * 8,
MaxIncomingStreams: 4,
KeepAlivePeriod: 10 * time.Second,
MaxIdleTimeout: time.Second * 120,
}
log.Debugln("opening new connection to %s", dc.addr)
var (
udp net.PacketConn
err error
)
host, port, err := net.SplitHostPort(dc.addr)
// we're using bootstrapped address instead of what's passed to the function
// it does not create an actual connection, but it helps us determine
// what IP is actually reachable (when there're v4/v6 addresses).
ctx, cancel := context.WithTimeout(context.Background(), DefaultTimeout)
rawConn, err := getDialHandler(doq.r, doq.proxyAdapter)(ctx, "udp", doq.addr)
if err != nil {
return nil, err
return nil, fmt.Errorf("failed to open a QUIC connection: %w", err)
}
// It's never actually used
_ = rawConn.Close()
cancel()
udpConn, ok := rawConn.(*net.UDPConn)
if !ok {
return nil, fmt.Errorf("failed to open connection to %s", doq.addr)
}
ip, err := resolver.ResolveIPv4WithResolver(host, dc.r)
addr := udpConn.RemoteAddr().String()
ip, port, err := net.SplitHostPort(addr)
if err != nil {
return nil, err
}
p, err := strconv.Atoi(port)
udpAddr := net.UDPAddr{IP: ip.AsSlice(), Port: p}
if dc.proxyAdapter == "" {
udpAddr := net.UDPAddr{IP: net.ParseIP(ip), Port: p}
var udp net.PacketConn
if doq.proxyAdapter == "" {
udp, err = dialer.ListenPacket(ctx, "udp", "")
if err != nil {
return nil, err
}
} else {
conn, err := dialContextExtra(ctx, dc.proxyAdapter, "udp", ip, port)
ipAddr, err := netip.ParseAddr(ip)
if err != nil {
return nil, err
}
conn, err := dialContextExtra(ctx, doq.proxyAdapter, "udp", ipAddr, port)
if err != nil {
return nil, err
}
@ -185,21 +361,158 @@ func (dc *quicClient) openConnection(ctx context.Context) (quic.Connection, erro
udp = wrapConn
}
session, err := quic.DialContext(ctx, udp, &udpAddr, host, tlsConfig, quicConfig)
if err != nil {
return nil, fmt.Errorf("failed to open QUIC connection: %w", err)
}
dc.udp = udp
return session, nil
}
func (dc *quicClient) openStream(ctx context.Context) (quic.Stream, error) {
session, err := dc.getConnection(ctx)
ctx, cancel = context.WithTimeout(context.Background(), DefaultTimeout)
defer cancel()
host, _, err := net.SplitHostPort(doq.addr)
if err != nil {
return nil, err
}
// open a new stream
return session.OpenStreamSync(ctx)
conn, err = quic.DialContext(ctx, udp, &udpAddr, host, tlsConfig, doq.getQUICConfig())
if err != nil {
return nil, fmt.Errorf("opening quic connection to %s: %w", doq.addr, err)
}
return conn, nil
}
// closeConnWithError closes the active connection with error to make sure that
// new queries were processed in another connection. We can do that in the case
// of a fatal error.
func (p *dnsOverQUIC) closeConnWithError(err error) {
p.connMu.Lock()
defer p.connMu.Unlock()
if p.conn == nil {
// Do nothing, there's no active conn anyways.
return
}
code := QUICCodeNoError
if err != nil {
code = QUICCodeInternalError
}
if errors.Is(err, quic.Err0RTTRejected) {
// Reset the TokenStore only if 0-RTT was rejected.
p.resetQUICConfig()
}
err = p.conn.CloseWithError(code, "")
if err != nil {
log.Errorln("failed to close the conn: %v", err)
}
p.conn = nil
}
// readMsg reads the incoming DNS message from the QUIC stream.
func (p *dnsOverQUIC) readMsg(stream quic.Stream) (m *D.Msg, err error) {
pool := p.getBytesPool()
bufPtr := pool.Get().(*[]byte)
defer pool.Put(bufPtr)
respBuf := *bufPtr
n, err := stream.Read(respBuf)
if err != nil && n == 0 {
return nil, fmt.Errorf("reading response from %s: %w", p.Address(), err)
}
// All DNS messages (queries and responses) sent over DoQ connections MUST
// be encoded as a 2-octet length field followed by the message content as
// specified in [RFC1035].
// IMPORTANT: Note, that we ignore this prefix here as this implementation
// does not support receiving multiple messages over a single connection.
m = new(D.Msg)
err = m.Unpack(respBuf[2:])
if err != nil {
return nil, fmt.Errorf("unpacking response from %s: %w", p.Address(), err)
}
return m, nil
}
// newQUICTokenStore creates a new quic.TokenStore that is necessary to have
// in order to benefit from 0-RTT.
func newQUICTokenStore() (s quic.TokenStore) {
// You can read more on address validation here:
// https://datatracker.ietf.org/doc/html/rfc9000#section-8.1
// Setting maxOrigins to 1 and tokensPerOrigin to 10 assuming that this is
// more than enough for the way we use it (one connection per upstream).
return quic.NewLRUTokenStore(1, 10)
}
// isQUICRetryError checks the error and determines whether it may signal that
// we should re-create the QUIC connection. This requirement is caused by
// quic-go issues, see the comments inside this function.
// TODO(ameshkov): re-test when updating quic-go.
func isQUICRetryError(err error) (ok bool) {
var qAppErr *quic.ApplicationError
if errors.As(err, &qAppErr) && qAppErr.ErrorCode == 0 {
// This error is often returned when the server has been restarted,
// and we try to use the same connection on the client-side. It seems,
// that the old connections aren't closed immediately on the server-side
// and that's why one can run into this.
// In addition to that, quic-go HTTP3 client implementation does not
// clean up dead connections (this one is specific to DoH3 upstream):
// https://github.com/lucas-clemente/quic-go/issues/765
return true
}
var qIdleErr *quic.IdleTimeoutError
if errors.As(err, &qIdleErr) {
// This error means that the connection was closed due to being idle.
// In this case we should forcibly re-create the QUIC connection.
// Reproducing is rather simple, stop the server and wait for 30 seconds
// then try to send another request via the same upstream.
return true
}
var resetErr *quic.StatelessResetError
if errors.As(err, &resetErr) {
// A stateless reset is sent when a server receives a QUIC packet that
// it doesn't know how to decrypt. For instance, it may happen when
// the server was recently rebooted. We should reconnect and try again
// in this case.
return true
}
var qTransportError *quic.TransportError
if errors.As(err, &qTransportError) && qTransportError.ErrorCode == quic.NoError {
// A transport error with the NO_ERROR error code could be sent by the
// server when it considers that it's time to close the connection.
// For example, Google DNS eventually closes an active connection with
// the NO_ERROR code and "Connection max age expired" message:
// https://github.com/AdguardTeam/dnsproxy/issues/283
return true
}
if errors.Is(err, quic.Err0RTTRejected) {
// This error happens when we try to establish a 0-RTT connection with
// a token the server is no more aware of. This can be reproduced by
// restarting the QUIC server (it will clear its tokens cache). The
// next connection attempt will return this error until the client's
// tokens cache is purged.
return true
}
return false
}
func getDialHandler(r *Resolver, proxyAdapter string) dialHandler {
return func(ctx context.Context, network, addr string) (net.Conn, error) {
host, port, err := net.SplitHostPort(addr)
if err != nil {
return nil, err
}
ip, err := r.ResolveIP(host)
if err != nil {
return nil, err
}
if len(proxyAdapter) == 0 {
return dialer.DialContext(ctx, network, net.JoinHostPort(ip.String(), port), dialer.WithDirect())
} else {
return dialContextExtra(ctx, proxyAdapter, network, ip.Unmap(), port, dialer.WithDirect())
}
}
}

1
dns/resolver.go
View File

@ -355,6 +355,7 @@ type NameServer struct {
Interface *atomic.String
ProxyAdapter string
Params map[string]string
PreferH3 bool
}
type FallbackFilter struct {

12
dns/util.go
View File

@ -19,6 +19,10 @@ import (
D "github.com/miekg/dns"
)
const (
MaxMsgSize = 65535
)
func putMsgToCache(c *cache.LruCache[string, *D.Msg], key string, msg *D.Msg) {
var ttl uint32
switch {
@ -59,13 +63,17 @@ func transform(servers []NameServer, resolver *Resolver) []dnsClient {
for _, s := range servers {
switch s.Net {
case "https":
ret = append(ret, newDoHClient(s.Addr, resolver, s.Params, s.ProxyAdapter))
ret = append(ret, newDoHClient(s.Addr, resolver, s.PreferH3, s.Params, s.ProxyAdapter))
continue
case "dhcp":
ret = append(ret, newDHCPClient(s.Addr))
continue
case "quic":
ret = append(ret, newDOQ(resolver, s.Addr, s.ProxyAdapter))
if doq, err := newDoQ(resolver, s.Addr, s.ProxyAdapter); err == nil {
ret = append(ret, doq)
}else{
log.Fatalln("DoQ format error: %v",err)
}
continue
}