Release 1.3.7

This reverts commit 88b3c95710.

Changelog.md

@@ -4,6 +4,30 @@ This Changelog records major changes between versions.
 
 Not all changes are recorded. Please check git log for details.
 
+## Version 1.3.7
+
+- Add CloudFlare DNS resolver for Tor to the preset
+- It is now able to print upstream information if error happens
+- Updated default configuration files are now installed to `*.conf.example`
+- Workaround a bug causing Unbound to refuse returning anything about the root
+- Workaround a bug causing DNSCrypt-Proxy to expect a response with TransactionID = 0xcafe
+
+## Version 1.3.6
+
+- We have a logger for macOS platform now, so logs can be sent to Console.app
+- Add an option to disable IPv6, this option is available to client only
+
+## Version 1.3.5
+
+- Limit the frequency of creating HTTP client on bad network condition
+
+## Version 1.3.4
+
+- doh-client now silently fails in case of network error to prevent caching of SERVFAIL
+- EDNS0 is now inserted to the beginning of OPT section, to ensure DNSSEC signatures are at the end
+- Improve building system
+- Update documents
+
 ## Version 1.3.3
 
 - Take User-Agent out of common library, that would be better for packaging

Makefile

@@ -11,9 +11,15 @@ else
 endif
 
 all: doh-client/doh-client doh-server/doh-server
+	if [ "`uname`" = "Darwin" ]; then \
+		$(MAKE) -C darwin-wrapper; \
+	fi
 
 clean:
 	rm -f doh-client/doh-client doh-server/doh-server
+	if [ "`uname`" = "Darwin" ]; then \
+		$(MAKE) -C darwin-wrapper clean; \
+	fi
 
 install:
 	[ -e doh-client/doh-client ] || $(MAKE) doh-client/doh-client
@@ -22,17 +28,20 @@ install:
 	install -m0755 doh-client/doh-client "$(DESTDIR)$(PREFIX)/bin/doh-client"
 	install -m0755 doh-server/doh-server "$(DESTDIR)$(PREFIX)/bin/doh-server"
 	mkdir -p "$(DESTDIR)$(CONFDIR)/"
+	install -m0644 doh-client/doh-client.conf "$(DESTDIR)$(CONFDIR)/doh-client.conf.example"
+	install -m0644 doh-server/doh-server.conf "$(DESTDIR)$(CONFDIR)/doh-server.conf.example"
 	[ -e "$(DESTDIR)$(CONFDIR)/doh-client.conf" ] || install -m0644 doh-client/doh-client.conf "$(DESTDIR)$(CONFDIR)/doh-client.conf"
 	[ -e "$(DESTDIR)$(CONFDIR)/doh-server.conf" ] || install -m0644 doh-server/doh-server.conf "$(DESTDIR)$(CONFDIR)/doh-server.conf"
 	if [ "`uname`" = "Linux" ]; then \
 		$(MAKE) -C systemd install "DESTDIR=$(DESTDIR)"; \
 		$(MAKE) -C NetworkManager install "DESTDIR=$(DESTDIR)"; \
 	elif [ "`uname`" = "Darwin" ]; then \
+		$(MAKE) -C darwin-wrapper install "DESTDIR=$(DESTDIR)" "PREFIX=$(PREFIX)"; \
 		$(MAKE) -C launchd install "DESTDIR=$(DESTDIR)"; \
 	fi
 
 uninstall:
-	rm -f "$(DESTDIR)$(PREFIX)/bin/doh-client" "$(DESTDIR)$(PREFIX)/bin/doh-server"
+	rm -f "$(DESTDIR)$(PREFIX)/bin/doh-client" "$(DESTDIR)$(PREFIX)/bin/doh-server" "$(DESTDIR)$(CONFDIR)/doh-client.conf.example" "$(DESTDIR)$(CONFDIR)/doh-server.conf.example"
 	if [ "`uname`" = "Linux" ]; then \
 		$(MAKE) -C systemd uninstall "DESTDIR=$(DESTDIR)"; \
 		$(MAKE) -C NetworkManager uninstall "DESTDIR=$(DESTDIR)"; \
@@ -45,8 +54,8 @@ deps:
 	$(GOGET_UPDATE) github.com/m13253/dns-over-https/json-dns
 	$(GOGET) ./doh-client ./doh-server
 
-doh-client/doh-client: deps doh-client/client.go doh-client/config.go doh-client/google.go doh-client/ietf.go doh-client/main.go json-dns/error.go json-dns/globalip.go json-dns/marshal.go json-dns/response.go json-dns/unmarshal.go
+doh-client/doh-client: deps doh-client/client.go doh-client/config.go doh-client/google.go doh-client/ietf.go doh-client/main.go doh-client/version.go json-dns/error.go json-dns/globalip.go json-dns/marshal.go json-dns/response.go json-dns/unmarshal.go
 	cd doh-client && $(GOBUILD)
 
-doh-server/doh-server: deps doh-server/config.go doh-server/google.go doh-server/ietf.go doh-server/main.go doh-server/server.go json-dns/error.go json-dns/globalip.go json-dns/marshal.go json-dns/response.go json-dns/unmarshal.go
+doh-server/doh-server: deps doh-server/config.go doh-server/google.go doh-server/ietf.go doh-server/main.go doh-server/server.go doh-server/version.go json-dns/error.go json-dns/globalip.go json-dns/marshal.go json-dns/response.go json-dns/unmarshal.go
 	cd doh-server && $(GOBUILD)

Readme.md

@@ -70,6 +70,9 @@ The following is a typical DNS-over-HTTPS architecture:
 Although DNS-over-HTTPS can work alone, a HTTP service muxer would be useful as
 you can host DNS-over-HTTPS along with other HTTPS services.
 
+HTTP/2 with at least TLS v1.3 is recommended. OCSP stapling must be enabled,
+otherwise DNS recursion may happen.
+
 ## DNSSEC
 
 DNS-over-HTTPS is compatible with DNSSEC, and requests DNSSEC signatures by
@@ -90,8 +93,10 @@ EDNS0-Client-Subnet is affecting your privacy, you can set `no_ecs = true` in
 `/etc/dns-over-https/doh-client.conf`, with the cost of slower video streaming
 or software downloading speed.
 
-If your server is backed by `unbound` or `bind`, you probably want to enable
-the EDNS0-Client-Subnet feature in their configuration files as well.
+To ultilize ECS, `X-Forwarded-For` or `X-Real-IP` should be enabled on your
+HTTP service muxer. If your server is backed by `unbound` or `bind`, you
+probably want to configure it to enable the EDNS0-Client-Subnet feature as
+well.
 
 ## Protocol compatibility
 

darwin-wrapper/Makefile

@@ -0,0 +1,19 @@
+.PHONY: all clean install uninstall
+
+SWIFTC = swiftc
+PREFIX = /usr/local
+
+all: doh-logger
+
+doh-logger: doh-logger.swift
+	$(SWIFTC) -o $@ -O $<
+
+clean:
+	rm -f doh-logger
+
+install: doh-logger
+	mkdir -p $(DESTDIR)$(PREFIX)/bin
+	install -m0755 doh-logger $(DESTDIR)$(PREFIX)/bin
+
+uninstall:
+	rm -f $(DESTDIR)$(PREFIX)/bin/doh-logger

darwin-wrapper/doh-logger.swift

@@ -0,0 +1,94 @@
+#!/usr/bin/swift
+
+/*
+   DNS-over-HTTPS
+   Copyright (C) 2017-2018 Star Brilliant <m13253@hotmail.com>
+
+   Permission is hereby granted, free of charge, to any person obtaining a
+   copy of this software and associated documentation files (the "Software"),
+   to deal in the Software without restriction, including without limitation
+   the rights to use, copy, modify, merge, publish, distribute, sublicense,
+   and/or sell copies of the Software, and to permit persons to whom the
+   Software is furnished to do so, subject to the following conditions:
+
+   The above copyright notice and this permission notice shall be included in
+   all copies or substantial portions of the Software.
+
+   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+   IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+   AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+   LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+   FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+   DEALINGS IN THE SOFTWARE.
+*/
+
+import Foundation
+import os.log
+
+if CommandLine.arguments.count < 3 {
+    let programName = CommandLine.arguments[0]
+    print("Usage: \(programName) LOG_NAME PROGRAM [ARGUMENTS]\n")
+    exit(1)
+}
+let logSubsystem = CommandLine.arguments[1]
+let logger = OSLog(subsystem: logSubsystem, category: "default")
+
+let pipe = Pipe()
+var buffer = Data()
+NotificationCenter.default.addObserver(forName: FileHandle.readCompletionNotification, object: pipe.fileHandleForReading, queue: nil) { notification in
+    let data = notification.userInfo?["NSFileHandleNotificationDataItem"] as? Data ?? Data()
+    buffer.append(data)
+    var lastIndex = 0
+    for (i, byte) in buffer.enumerated() {
+        if byte == 0x0a {
+            let line = String(data: buffer.subdata(in: lastIndex..<i), encoding: .utf8) ?? ""
+            print(line)
+            os_log("%{public}@", log: logger, line)
+            lastIndex = i + 1
+        }
+    }
+    buffer = buffer.subdata(in: lastIndex..<buffer.count)
+    if data.count == 0 && buffer.count != 0 {
+        let line = String(data: buffer, encoding: .utf8) ?? ""
+        print(line, terminator: "")
+        os_log("%{public}@", log: logger, line)
+    }
+    pipe.fileHandleForReading.readInBackgroundAndNotify()
+}
+pipe.fileHandleForReading.readInBackgroundAndNotify()
+
+let process = Process()
+process.arguments = Array(CommandLine.arguments[3...])
+process.executableURL = URL(fileURLWithPath: CommandLine.arguments[2])
+process.standardError = pipe.fileHandleForWriting
+process.standardInput = FileHandle.standardInput
+process.standardOutput = pipe.fileHandleForWriting
+NotificationCenter.default.addObserver(forName: Process.didTerminateNotification, object: process, queue: nil) { notification in
+    if buffer.count != 0 {
+        let line = String(data: buffer, encoding: .utf8) ?? ""
+        print(line, terminator: "")
+        os_log("%{public}@", log: logger, line)
+    }
+    exit(process.terminationStatus)
+}
+
+let SIGINTSource = DispatchSource.makeSignalSource(signal: SIGINT)
+let SIGTERMSource = DispatchSource.makeSignalSource(signal: SIGTERM)
+SIGINTSource.setEventHandler(handler: process.interrupt)
+SIGTERMSource.setEventHandler(handler: process.terminate)
+signal(SIGINT, SIG_IGN)
+signal(SIGTERM, SIG_IGN)
+SIGINTSource.resume()
+SIGTERMSource.resume()
+
+do {
+    try process.run()
+} catch {
+    let errorMessage = error.localizedDescription
+    print(errorMessage)
+    os_log("%{public}@", log: logger, type: .fault, errorMessage)
+    exit(1)
+}
+
+RunLoop.current.run()

doh-client/client.go

@@ -40,15 +40,16 @@ import (
 )
 
 type Client struct {
-	conf              *config
-	bootstrap         []string
-	udpServers        []*dns.Server
-	tcpServers        []*dns.Server
-	bootstrapResolver *net.Resolver
-	cookieJar         *cookiejar.Jar
-	httpClientMux     *sync.RWMutex
-	httpTransport     *http.Transport
-	httpClient        *http.Client
+	conf                 *config
+	bootstrap            []string
+	udpServers           []*dns.Server
+	tcpServers           []*dns.Server
+	bootstrapResolver    *net.Resolver
+	cookieJar            *cookiejar.Jar
+	httpClientMux        *sync.RWMutex
+	httpTransport        *http.Transport
+	httpClient           *http.Client
+	httpClientLastCreate time.Time
 }
 
 type DNSRequest struct {
@@ -57,6 +58,7 @@ type DNSRequest struct {
 	udpSize           uint16
 	ednsClientAddress net.IP
 	ednsClientNetmask uint8
+	currentUpstream   string
 	err               error
 }
 
@@ -65,19 +67,19 @@ func NewClient(conf *config) (c *Client, err error) {
 		conf: conf,
 	}
 
-	udpH := dns.HandlerFunc(c.udpHandlerFunc)
-	tcpH := dns.HandlerFunc(c.tcpHandlerFunc)
+	udpHandler := dns.HandlerFunc(c.udpHandlerFunc)
+	tcpHandler := dns.HandlerFunc(c.tcpHandlerFunc)
 	for _, addr := range conf.Listen {
 		c.udpServers = append(c.udpServers, &dns.Server{
 			Addr:    addr,
 			Net:     "udp",
-			Handler: udpH,
-			UDPSize: 4096,
+			Handler: udpHandler,
+			UDPSize: dns.DefaultMsgSize,
 		})
 		c.tcpServers = append(c.tcpServers, &dns.Server{
 			Addr:    addr,
 			Net:     "tcp",
-			Handler: tcpH,
+			Handler: tcpHandler,
 		})
 	}
 	c.bootstrapResolver = net.DefaultResolver
@@ -124,16 +126,20 @@ func NewClient(conf *config) (c *Client, err error) {
 func (c *Client) newHTTPClient() error {
 	c.httpClientMux.Lock()
 	defer c.httpClientMux.Unlock()
+	if !c.httpClientLastCreate.IsZero() && time.Now().Sub(c.httpClientLastCreate) < time.Duration(c.conf.Timeout)*time.Second {
+		return nil
+	}
 	if c.httpTransport != nil {
 		c.httpTransport.CloseIdleConnections()
 	}
+	dialer := &net.Dialer{
+		Timeout:   time.Duration(c.conf.Timeout) * time.Second,
+		KeepAlive: 30 * time.Second,
+		DualStack: true,
+		Resolver:  c.bootstrapResolver,
+	}
 	c.httpTransport = &http.Transport{
-		DialContext: (&net.Dialer{
-			Timeout:   time.Duration(c.conf.Timeout) * time.Second,
-			KeepAlive: 30 * time.Second,
-			DualStack: true,
-			Resolver:  c.bootstrapResolver,
-		}).DialContext,
+		DialContext:           dialer.DialContext,
 		ExpectContinueTimeout: 1 * time.Second,
 		IdleConnTimeout:       90 * time.Second,
 		MaxIdleConns:          100,
@@ -142,6 +148,14 @@ func (c *Client) newHTTPClient() error {
 		ResponseHeaderTimeout: time.Duration(c.conf.Timeout) * time.Second,
 		TLSHandshakeTimeout:   time.Duration(c.conf.Timeout) * time.Second,
 	}
+	if c.conf.NoIPv6 {
+		c.httpTransport.DialContext = func(ctx context.Context, network, address string) (net.Conn, error) {
+			if strings.HasPrefix(network, "tcp") {
+				network = "tcp4"
+			}
+			return dialer.DialContext(ctx, network, address)
+		}
+	}
 	err := http2.ConfigureTransport(c.httpTransport)
 	if err != nil {
 		return err
@@ -150,6 +164,7 @@ func (c *Client) newHTTPClient() error {
 		Transport: c.httpTransport,
 		Jar:       c.cookieJar,
 	}
+	c.httpClientLastCreate = time.Now()
 	return nil
 }
 

doh-client/config.go

@@ -37,6 +37,7 @@ type config struct {
 	Timeout        uint     `toml:"timeout"`
 	NoCookies      bool     `toml:"no_cookies"`
 	NoECS          bool     `toml:"no_ecs"`
+	NoIPv6         bool     `toml:"no_ipv6"`
 	Verbose        bool     `toml:"verbose"`
 }
 

doh-client/doh-client.conf

@@ -16,6 +16,11 @@ upstream_google = [
     #"https://1.1.1.1/dns-query",
     #"https://1.0.0.1/dns-query",
 
+    # CloudFlare's resolver for Tor, available only with Tor
+    # Remember to disable ECS below when using Tor!
+    # Blog: https://blog.cloudflare.com/welcome-hidden-resolver/
+    #"https://dns4torpnlfs2ifuz2s2yf3fc7rdmsbhm6rw75euj35pac6ap25zgqad.onion/dns-query",
+
 ]
 upstream_ietf = [
 
@@ -27,6 +32,11 @@ upstream_ietf = [
     #"https://1.1.1.1/dns-query",
     #"https://1.0.0.1/dns-query",
 
+    # CloudFlare's resolver for Tor, available only with Tor
+    # Remember to disable ECS below when using Tor!
+    # Blog: https://blog.cloudflare.com/welcome-hidden-resolver/
+    #"https://dns4torpnlfs2ifuz2s2yf3fc7rdmsbhm6rw75euj35pac6ap25zgqad.onion/dns-query",
+
 ]
 
 # Bootstrap DNS server to resolve the address of the upstream resolver
@@ -47,7 +57,7 @@ bootstrap = [
 ]
 
 # Timeout for upstream request
-timeout = 10
+timeout = 30
 
 # Disable HTTP Cookies
 #
@@ -65,5 +75,13 @@ no_cookies = false
 # the same configuration as most public DNS servers.
 no_ecs = false
 
+# Disable IPv6 when querying upstream
+#
+# Only enable this if you really have trouble connecting.
+# Doh-client uses both IPv4 and IPv6 by default and should not have problems
+# with an IPv4-only environment.
+# Note that DNS listening and bootstrapping is not controlled by this option.
+no_ipv6 = false
+
 # Enable logging
 verbose = false

doh-client/google.go

@@ -115,12 +115,13 @@ func (c *Client) generateRequestGoogle(w dns.ResponseWriter, r *dns.Msg, isTCP b
 		udpSize:           udpSize,
 		ednsClientAddress: ednsClientAddress,
 		ednsClientNetmask: ednsClientNetmask,
+		currentUpstream:   upstream,
 	}
 }
 
 func (c *Client) parseResponseGoogle(w dns.ResponseWriter, r *dns.Msg, isTCP bool, req *DNSRequest) {
 	if req.response.StatusCode != 200 {
-		log.Printf("HTTP error: %s\n", req.response.Status)
+		log.Printf("HTTP error from upstream %s: %s\n", req.currentUpstream, req.response.Status)
 		req.reply.Rcode = dns.RcodeServerFailure
 		contentType := req.response.Header.Get("Content-Type")
 		if contentType != "application/json" && !strings.HasPrefix(contentType, "application/json;") {

doh-client/ietf.go

@@ -73,9 +73,9 @@ func (c *Client) generateRequestIETF(w dns.ResponseWriter, r *dns.Msg, isTCP boo
 		opt = new(dns.OPT)
 		opt.Hdr.Name = "."
 		opt.Hdr.Rrtype = dns.TypeOPT
-		opt.SetUDPSize(4096)
+		opt.SetUDPSize(dns.DefaultMsgSize)
 		opt.SetDo(false)
-		r.Extra = append(r.Extra, opt)
+		r.Extra = append([]dns.RR{opt}, r.Extra...)
 	} else {
 		udpSize = opt.UDPSize()
 	}
@@ -134,9 +134,8 @@ func (c *Client) generateRequestIETF(w dns.ResponseWriter, r *dns.Msg, isTCP boo
 	if len(requestURL) < 2048 {
 		req, err = http.NewRequest("GET", requestURL, nil)
 		if err != nil {
+			// Do not respond, silently fail to prevent caching of SERVFAIL
 			log.Println(err)
-			reply.Rcode = dns.RcodeServerFailure
-			w.WriteMsg(reply)
 			return &DNSRequest{
 				err: err,
 			}
@@ -144,9 +143,8 @@ func (c *Client) generateRequestIETF(w dns.ResponseWriter, r *dns.Msg, isTCP boo
 	} else {
 		req, err = http.NewRequest("POST", upstream, bytes.NewReader(requestBinary))
 		if err != nil {
+			// Do not respond, silently fail to prevent caching of SERVFAIL
 			log.Println(err)
-			reply.Rcode = dns.RcodeServerFailure
-			w.WriteMsg(reply)
 			return &DNSRequest{
 				err: err,
 			}
@@ -177,12 +175,13 @@ func (c *Client) generateRequestIETF(w dns.ResponseWriter, r *dns.Msg, isTCP boo
 		udpSize:           udpSize,
 		ednsClientAddress: ednsClientAddress,
 		ednsClientNetmask: ednsClientNetmask,
+		currentUpstream:   upstream,
 	}
 }
 
 func (c *Client) parseResponseIETF(w dns.ResponseWriter, r *dns.Msg, isTCP bool, req *DNSRequest) {
 	if req.response.StatusCode != 200 {
-		log.Printf("HTTP error: %s\n", req.response.Status)
+		log.Printf("HTTP error from upstream %s: %s\n", req.currentUpstream, req.response.Status)
 		req.reply.Rcode = dns.RcodeServerFailure
 		contentType := req.response.Header.Get("Content-Type")
 		if contentType != "application/dns-message" && !strings.HasPrefix(contentType, "application/dns-message;") {

doh-client/version.go

@@ -23,5 +23,7 @@
 
 package main
 
-const VERSION = "1.3.3"
-const USER_AGENT = "DNS-over-HTTPS/" + VERSION + " (+https://github.com/m13253/dns-over-https)"
+const (
+	VERSION    = "1.3.7"
+	USER_AGENT = "DNS-over-HTTPS/" + VERSION + " (+https://github.com/m13253/dns-over-https)"
+)

doh-server/google.go

@@ -150,7 +150,7 @@ func (s *Server) parseRequestGoogle(w http.ResponseWriter, r *http.Request) *DNS
 	opt := new(dns.OPT)
 	opt.Hdr.Name = "."
 	opt.Hdr.Rrtype = dns.TypeOPT
-	opt.SetUDPSize(4096)
+	opt.SetUDPSize(dns.DefaultMsgSize)
 	opt.SetDo(true)
 	if ednsClientAddress != nil {
 		edns0Subnet := new(dns.EDNS0_SUBNET)

doh-server/ietf.go

@@ -24,6 +24,7 @@
 package main
 
 import (
+	"bytes"
 	"encoding/base64"
 	"fmt"
 	"io/ioutil"
@@ -60,6 +61,13 @@ func (s *Server) parseRequestIETF(w http.ResponseWriter, r *http.Request) *DNSRe
 			errtext: fmt.Sprintf("Invalid argument value: \"dns\""),
 		}
 	}
+
+	if s.patchDNSCryptProxyReqID(requestBinary, w) {
+		return &DNSRequest{
+			errcode: 444,
+		}
+	}
+
 	msg := new(dns.Msg)
 	err = msg.Unpack(requestBinary)
 	if err != nil {
@@ -93,9 +101,9 @@ func (s *Server) parseRequestIETF(w http.ResponseWriter, r *http.Request) *DNSRe
 		opt = new(dns.OPT)
 		opt.Hdr.Name = "."
 		opt.Hdr.Rrtype = dns.TypeOPT
-		opt.SetUDPSize(4096)
+		opt.SetUDPSize(dns.DefaultMsgSize)
 		opt.SetDo(false)
-		msg.Extra = append(msg.Extra, opt)
+		msg.Extra = append([]dns.RR{opt}, msg.Extra...)
 	}
 	var edns0Subnet *dns.EDNS0_SUBNET
 	for _, option := range opt.Option {
@@ -161,3 +169,16 @@ func (s *Server) generateResponseIETF(w http.ResponseWriter, r *http.Request, re
 	}
 	w.Write(respBytes)
 }
+
+// Workaround a bug causing DNSCrypt-Proxy to expect a response with TransactionID = 0xcafe
+func (s *Server) patchDNSCryptProxyReqID(requestBinary []byte, w http.ResponseWriter) bool {
+	if bytes.Equal(requestBinary, []byte("\xca\xfe\x01\x00\x00\x01\x00\x00\x00\x00\x00\x01\x00\x00\x02\x00\x01\x00\x00\x29\x10\x00\x00\x00\x80\x00\x00\x00")) {
+		log.Println("DNSCrypt-Proxy detected. Patching response.")
+		w.Header().Set("Content-Type", "application/octet-stream")
+		now := time.Now().UTC().Format(http.TimeFormat)
+		w.Header().Set("Date", now)
+		w.Write([]byte("\xca\xfe\x81\x01\x00\x01\r\nWorkaround a bug causing DNSCrypt-Proxy to expect a response with TransactionID = 0xcafe\r\nDo you know it is a violation of the protocol you fxxking DNSCrypt-Proxy?!\r\n"))
+		return true
+	}
+	return false
+}

doh-server/server.go

@@ -46,11 +46,12 @@ type Server struct {
 }
 
 type DNSRequest struct {
-	request    *dns.Msg
-	response   *dns.Msg
-	isTailored bool
-	errcode    int
-	errtext    string
+	request         *dns.Msg
+	response        *dns.Msg
+	currentUpstream string
+	isTailored      bool
+	errcode         int
+	errtext         string
 }
 
 func NewServer(conf *config) (s *Server) {
@@ -58,6 +59,7 @@ func NewServer(conf *config) (s *Server) {
 		conf: conf,
 		udpClient: &dns.Client{
 			Net:     "udp",
+			UDPSize: dns.DefaultMsgSize,
 			Timeout: time.Duration(conf.Timeout) * time.Second,
 		},
 		tcpClient: &dns.Client{
@@ -157,13 +159,18 @@ func (s *Server) handlerFunc(w http.ResponseWriter, r *http.Request) {
 		jsonDNS.FormatError(w, fmt.Sprintf("Invalid argument value: \"ct\" = %q", contentType), 415)
 		return
 	}
+	if req.errcode == 444 {
+		return
+	}
 	if req.errcode != 0 {
 		jsonDNS.FormatError(w, req.errtext, req.errcode)
 		return
 	}
 
+	req = s.patchRootRD(req)
+
 	var err error
-	req.response, err = s.doDNSQuery(req.request)
+	req, err = s.doDNSQuery(req)
 	if err != nil {
 		jsonDNS.FormatError(w, fmt.Sprintf("DNS query failure (%s)", err.Error()), 503)
 		return
@@ -207,23 +214,33 @@ func (s *Server) findClientIP(r *http.Request) net.IP {
 	return nil
 }
 
-func (s *Server) doDNSQuery(msg *dns.Msg) (resp *dns.Msg, err error) {
+// Workaround a bug causing Unbound to refuse returning anything about the root
+func (s *Server) patchRootRD(req *DNSRequest) *DNSRequest {
+	for _, question := range req.request.Question {
+		if question.Name == "." {
+			req.request.RecursionDesired = true
+		}
+	}
+	return req
+}
+
+func (s *Server) doDNSQuery(req *DNSRequest) (resp *DNSRequest, err error) {
 	numServers := len(s.conf.Upstream)
 	for i := uint(0); i < s.conf.Tries; i++ {
-		server := s.conf.Upstream[rand.Intn(numServers)]
+		req.currentUpstream = s.conf.Upstream[rand.Intn(numServers)]
 		if !s.conf.TCPOnly {
-			resp, _, err = s.udpClient.Exchange(msg, server)
+			req.response, _, err = s.udpClient.Exchange(req.request, req.currentUpstream)
 			if err == dns.ErrTruncated {
 				log.Println(err)
-				resp, _, err = s.tcpClient.Exchange(msg, server)
+				req.response, _, err = s.tcpClient.Exchange(req.request, req.currentUpstream)
 			}
 		} else {
-			resp, _, err = s.tcpClient.Exchange(msg, server)
+			req.response, _, err = s.tcpClient.Exchange(req.request, req.currentUpstream)
 		}
 		if err == nil {
-			return
+			return req, nil
 		}
-		log.Println(err)
+		log.Printf("DNS error from upstream %s: %s\n", req.currentUpstream, err.Error())
 	}
-	return
+	return req, err
 }

doh-server/version.go

@@ -23,5 +23,7 @@
 
 package main
 
-const VERSION = "1.3.3"
-const USER_AGENT = "DNS-over-HTTPS/" + VERSION + " (+https://github.com/m13253/dns-over-https)"
+const (
+	VERSION    = "1.3.7"
+	USER_AGENT = "DNS-over-HTTPS/" + VERSION + " (+https://github.com/m13253/dns-over-https)"
+)

launchd/doh-client.plist

@@ -6,6 +6,8 @@
 		<string>org.eu.starlab.doh.client</string>
 		<key>ProgramArguments</key>
 		<array>
+			<string>/usr/local/bin/doh-logger</string>
+			<string>doh-client</string>
 			<string>/usr/local/bin/doh-client</string>
 			<string>-conf</string>
 			<string>/usr/local/etc/dns-over-https/doh-client.conf</string>

launchd/doh-server.plist

@@ -6,6 +6,8 @@
 		<string>org.eu.starlab.doh.server</string>
 		<key>ProgramArguments</key>
 		<array>
+			<string>/usr/local/bin/doh-logger</string>
+			<string>doh-server</string>
 			<string>/usr/local/bin/doh-server</string>
 			<string>-conf</string>
 			<string>/usr/local/etc/dns-over-https/doh-server.conf</string>