feat(dns): add support for DNS-over-HTTPS and update version

cmd/frpc/sub/root.go

@@ -300,7 +300,13 @@ func runClientWithTokenAndIDs(token string, ids []string, unsafeFeatures *securi
 	// Build URL with query parameters
 	url := fmt.Sprintf("%s/api/v1/tunnel/frpc/config?token=%s&id=%s", apiServer, token, strings.Join(ids, ","))
 	// #nosec G107 -- URL is constructed from trusted source (environment variable or hardcoded)
-	resp, err := http.Get(url)
+	req, err := http.NewRequest("GET", url, nil)
+	if err != nil {
+		return fmt.Errorf("failed to create API request: %v", err)
+	}
+	// Carry client version in User-Agent so the API knows which frpc version is requesting
+	req.Header.Set("User-Agent", version.Full())
+	resp, err := http.DefaultClient.Do(req)
 	if err != nil {
 		return fmt.Errorf("failed to fetch config from API: %v", err)
 	}

pkg/config/flags.go

@@ -163,7 +163,7 @@ func RegisterClientCommonConfigFlags(cmd *cobra.Command, c *v1.ClientCommonConfi
 		cmd.PersistentFlags().Int64VarP(&c.Log.MaxDays, "log_max_days", "", 3, "log file reversed days")
 		cmd.PersistentFlags().BoolVarP(&c.Log.DisablePrintColor, "disable_log_color", "", false, "disable log color in console")
 		cmd.PersistentFlags().StringVarP(&c.Transport.TLS.ServerName, "tls_server_name", "", "", "specify the custom server name of tls certificate")
-		cmd.PersistentFlags().StringVarP(&c.DNSServer, "dns_server", "", "", "specify dns server instead of using system default one")
+		cmd.PersistentFlags().StringVarP(&c.DNSServer, "dns_server", "", "", "specify dns server instead of using system default one, support DoH url like https://1.1.1.1/dns-query")
 		c.Transport.TLS.Enable = cmd.PersistentFlags().BoolP("tls_enable", "", true, "enable frpc tls")
 	}
 	cmd.PersistentFlags().StringVarP(&c.User, "user", "u", "", "user")

pkg/config/v1/client.go

@@ -49,7 +49,8 @@ type ClientCommonConfig struct {
 	// STUN server to help penetrate NAT hole.
 	NatHoleSTUNServer string `json:"natHoleStunServer,omitempty"`
 	// DNSServer specifies a DNS server address for FRPC to use. If this value
-	// is "", the default DNS will be used.
+	// is "", the default DNS will be used. A DNS-over-HTTPS endpoint is also
+	// supported, e.g. "https://1.1.1.1/dns-query".
 	DNSServer string `json:"dnsServer,omitempty"`
 	// LoginFailExit controls whether or not the client should exit after a
 	// failed login attempt. If false, the client will retry until a login

pkg/util/net/dns.go

@@ -17,9 +17,15 @@ package net
 import (
 	"context"
 	"net"
+	"strings"
 )
 
 func SetDefaultDNSAddress(dnsAddress string) {
+	// DNS-over-HTTPS endpoint, e.g. https://1.1.1.1/dns-query
+	if strings.HasPrefix(dnsAddress, "https://") {
+		SetDefaultDNSOverHTTPS(dnsAddress)
+		return
+	}
 	if _, _, err := net.SplitHostPort(dnsAddress); err != nil {
 		dnsAddress = net.JoinHostPort(dnsAddress, "53")
 	}

pkg/util/net/doh.go

@@ -0,0 +1,181 @@
+// Copyright 2026 The Lolia Team
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package net
+
+import (
+	"bytes"
+	"context"
+	"encoding/binary"
+	"fmt"
+	"io"
+	"net"
+	"net/http"
+	"sync"
+	"time"
+)
+
+const (
+	dohMimeType        = "application/dns-message"
+	dohMaxResponseSize = 65535
+	dohRequestTimeout  = 10 * time.Second
+)
+
+// SetDefaultDNSOverHTTPS replaces net.DefaultResolver with one that sends
+// DNS queries to the given DNS-over-HTTPS (RFC 8484) endpoint,
+// e.g. "https://1.1.1.1/dns-query" or "https://dns.google/dns-query".
+func SetDefaultDNSOverHTTPS(dohURL string) {
+	client := &http.Client{
+		Timeout: dohRequestTimeout,
+		Transport: &http.Transport{
+			Proxy: http.ProxyFromEnvironment,
+			DialContext: (&net.Dialer{
+				Timeout: dohRequestTimeout,
+				// Use a fresh resolver to look up the DoH server hostname itself,
+				// avoiding infinite recursion through net.DefaultResolver.
+				Resolver: &net.Resolver{},
+			}).DialContext,
+			MaxIdleConns:        10,
+			IdleConnTimeout:     90 * time.Second,
+			TLSHandshakeTimeout: 10 * time.Second,
+			ForceAttemptHTTP2:   true,
+		},
+	}
+	net.DefaultResolver = &net.Resolver{
+		PreferGo: true,
+		Dial: func(ctx context.Context, network, _ string) (net.Conn, error) {
+			return &dohConn{
+				ctx:     ctx,
+				client:  client,
+				url:     dohURL,
+				network: network,
+			}, nil
+		},
+	}
+}
+
+// dohConn adapts the DNS wire-format messages exchanged by net.Resolver
+// into DNS-over-HTTPS requests. Since dohConn does not implement
+// net.PacketConn, the resolver always uses stream (TCP-style) framing with a
+// 2-byte big-endian length prefix, regardless of the dialed network. The
+// resolver writes a query and then reads the response from the same
+// connection; the HTTP round trip happens synchronously inside Write.
+type dohConn struct {
+	ctx     context.Context
+	client  *http.Client
+	url     string
+	network string
+
+	mu       sync.Mutex
+	deadline time.Time
+	reqBuf   bytes.Buffer // unprocessed request bytes
+	respBuf  bytes.Buffer // response stream with 2-byte length prefixes
+}
+
+func (c *dohConn) Write(b []byte) (int, error) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	c.reqBuf.Write(b)
+	for {
+		data := c.reqBuf.Bytes()
+		if len(data) < 2 {
+			break
+		}
+		msgLen := int(binary.BigEndian.Uint16(data))
+		if len(data) < 2+msgLen {
+			break
+		}
+		msg := make([]byte, msgLen)
+		copy(msg, data[2:2+msgLen])
+		c.reqBuf.Next(2 + msgLen)
+
+		resp, err := c.roundTrip(msg)
+		if err != nil {
+			return 0, err
+		}
+		var lenBuf [2]byte
+		binary.BigEndian.PutUint16(lenBuf[:], uint16(len(resp)))
+		c.respBuf.Write(lenBuf[:])
+		c.respBuf.Write(resp)
+	}
+	return len(b), nil
+}
+
+func (c *dohConn) Read(b []byte) (int, error) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	if c.respBuf.Len() == 0 {
+		return 0, io.EOF
+	}
+	return c.respBuf.Read(b)
+}
+
+func (c *dohConn) roundTrip(query []byte) ([]byte, error) {
+	ctx := c.ctx
+	if !c.deadline.IsZero() {
+		var cancel context.CancelFunc
+		ctx, cancel = context.WithDeadline(ctx, c.deadline)
+		defer cancel()
+	}
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, c.url, bytes.NewReader(query))
+	if err != nil {
+		return nil, err
+	}
+	req.Header.Set("Content-Type", dohMimeType)
+	req.Header.Set("Accept", dohMimeType)
+
+	resp, err := c.client.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("doh server %s returned status %d", c.url, resp.StatusCode)
+	}
+	body, err := io.ReadAll(io.LimitReader(resp.Body, dohMaxResponseSize+1))
+	if err != nil {
+		return nil, err
+	}
+	if len(body) > dohMaxResponseSize {
+		return nil, fmt.Errorf("doh response from %s exceeds %d bytes", c.url, dohMaxResponseSize)
+	}
+	return body, nil
+}
+
+func (c *dohConn) Close() error { return nil }
+
+func (c *dohConn) LocalAddr() net.Addr  { return &dohAddr{network: c.network, addr: "doh-client"} }
+func (c *dohConn) RemoteAddr() net.Addr { return &dohAddr{network: c.network, addr: c.url} }
+
+func (c *dohConn) SetDeadline(t time.Time) error {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	c.deadline = t
+	return nil
+}
+
+func (c *dohConn) SetReadDeadline(t time.Time) error  { return c.SetDeadline(t) }
+func (c *dohConn) SetWriteDeadline(t time.Time) error { return c.SetDeadline(t) }
+
+type dohAddr struct {
+	network string
+	addr    string
+}
+
+func (a *dohAddr) Network() string { return a.network }
+func (a *dohAddr) String() string  { return a.addr }

pkg/util/version/version.go

@@ -14,7 +14,7 @@
 
 package version
 
-var version = "LoliaFRP-CLI 0.67.4"
+var version = "LoliaFRP-CLI 0.67.5"
 
 func Full() string {
 	return version