all: support ipv6 for doh3 upstream bootstrap ip

We did it for doh, but the doh3 transport also needs to be changed.

config.go

@@ -2,6 +2,7 @@ package ctrld
 
 import (
 	"context"
+	"crypto/tls"
 	"net"
 	"net/http"
 	"net/url"
@@ -10,6 +11,8 @@ import (
 
 	"github.com/Control-D-Inc/ctrld/internal/dnsrcode"
 	"github.com/go-playground/validator/v10"
+	"github.com/lucas-clemente/quic-go"
+	"github.com/lucas-clemente/quic-go/http3"
 	"github.com/miekg/dns"
 	"github.com/spf13/viper"
 )
@@ -79,13 +82,14 @@ type NetworkConfig struct {
 
 // UpstreamConfig specifies configuration for upstreams that ctrld will forward requests to.
 type UpstreamConfig struct {
-	Name        string          `mapstructure:"name" toml:"name"`
+	Name              string              `mapstructure:"name" toml:"name"`
-	Type        string          `mapstructure:"type" toml:"type" validate:"oneof=doh doh3 dot doq os legacy"`
+	Type              string              `mapstructure:"type" toml:"type" validate:"oneof=doh doh3 dot doq os legacy"`
-	Endpoint    string          `mapstructure:"endpoint" toml:"endpoint" validate:"required_unless=Type os"`
+	Endpoint          string              `mapstructure:"endpoint" toml:"endpoint" validate:"required_unless=Type os"`
-	BootstrapIP string          `mapstructure:"bootstrap_ip" toml:"bootstrap_ip"`
+	BootstrapIP       string              `mapstructure:"bootstrap_ip" toml:"bootstrap_ip"`
-	Domain      string          `mapstructure:"-" toml:"-"`
+	Domain            string              `mapstructure:"-" toml:"-"`
-	Timeout     int             `mapstructure:"timeout" toml:"timeout" validate:"gte=0"`
+	Timeout           int                 `mapstructure:"timeout" toml:"timeout" validate:"gte=0"`
-	transport   *http.Transport `mapstructure:"-" toml:"-"`
+	transport         *http.Transport     `mapstructure:"-" toml:"-"`
+	http3RoundTripper *http3.RoundTripper `mapstructure:"-" toml:"-"`
 }
 
 // ListenerConfig specifies the networks configuration that ctrld will run on.
@@ -133,9 +137,15 @@ func (uc *UpstreamConfig) Init() {
 // SetupTransport initializes the network transport used to connect to upstream server.
 // For now, only DoH upstream is supported.
 func (uc *UpstreamConfig) SetupTransport() {
-	if uc.Type != resolverTypeDOH {
+	switch uc.Type {
-		return
+	case resolverTypeDOH:
+		uc.setupDOHTransport()
+	case resolverTypeDOH3:
+		uc.setupDOH3Transport()
 	}
+}
+
+func (uc *UpstreamConfig) setupDOHTransport() {
 	uc.transport = http.DefaultTransport.(*http.Transport).Clone()
 	uc.transport.DialContext = func(ctx context.Context, network, addr string) (net.Conn, error) {
 		dialer := &net.Dialer{
@@ -153,6 +163,40 @@ func (uc *UpstreamConfig) SetupTransport() {
 		return dialer.DialContext(ctx, network, addr)
 	}
 
+	uc.pingUpstream()
+}
+
+func (uc *UpstreamConfig) setupDOH3Transport() {
+	uc.http3RoundTripper = &http3.RoundTripper{}
+	uc.http3RoundTripper.Dial = func(ctx context.Context, addr string, tlsCfg *tls.Config, cfg *quic.Config) (quic.EarlyConnection, error) {
+		host := addr
+		ProxyLog.Debug().Msgf("debug dial context D0H3 %s - %s", addr, bootstrapDNS)
+		// if we have a bootstrap ip set, use it to avoid DNS lookup
+		if uc.BootstrapIP != "" {
+			if _, port, _ := net.SplitHostPort(addr); port != "" {
+				addr = net.JoinHostPort(uc.BootstrapIP, port)
+			}
+			ProxyLog.Debug().Msgf("sending doh3 request to: %s", addr)
+		}
+		remoteAddr, err := net.ResolveUDPAddr("udp", addr)
+		if err != nil {
+			return nil, err
+		}
+		localAddr := &net.UDPAddr{IP: net.IPv4zero, Port: 0}
+		if strings.Index(uc.BootstrapIP, ":") > -1 {
+			localAddr = &net.UDPAddr{IP: net.IPv6zero, Port: 0}
+		}
+		udpConn, err := net.ListenUDP("udp", localAddr)
+		if err != nil {
+			return nil, err
+		}
+		return quic.DialEarlyContext(ctx, udpConn, remoteAddr, host, tlsCfg, cfg)
+	}
+
+	uc.pingUpstream()
+}
+
+func (uc *UpstreamConfig) pingUpstream() {
 	// Warming up the transport by querying a test packet.
 	dnsResolver, err := NewResolver(uc)
 	if err != nil {

doh.go

@@ -2,52 +2,30 @@ package ctrld
 
 import (
 	"context"
-	"crypto/tls"
 	"encoding/base64"
 	"fmt"
 	"io"
-	"net"
 	"net/http"
 
-	"github.com/lucas-clemente/quic-go"
 	"github.com/lucas-clemente/quic-go/http3"
 	"github.com/miekg/dns"
 )
 
 func newDohResolver(uc *UpstreamConfig) *dohResolver {
 	r := &dohResolver{
-		endpoint:  uc.Endpoint,
+		endpoint:          uc.Endpoint,
-		isDoH3:    uc.Type == resolverTypeDOH3,
+		isDoH3:            uc.Type == resolverTypeDOH3,
-		transport: uc.transport,
+		transport:         uc.transport,
-	}
+		http3RoundTripper: uc.http3RoundTripper,
-	if r.isDoH3 {
-		r.doh3DialFunc = func(ctx context.Context, addr string, tlsCfg *tls.Config, cfg *quic.Config) (quic.EarlyConnection, error) {
-			host := addr
-			Log(ctx, ProxyLog.Debug(), "debug dial context D0H3 %s - %s", addr, bootstrapDNS)
-			// if we have a bootstrap ip set, use it to avoid DNS lookup
-			if uc.BootstrapIP != "" && addr == fmt.Sprintf("%s:443", uc.Domain) {
-				addr = fmt.Sprintf("%s:443", uc.BootstrapIP)
-				Log(ctx, ProxyLog.Debug(), "sending doh3 request to: %s", addr)
-			}
-			remoteAddr, err := net.ResolveUDPAddr("udp", addr)
-			if err != nil {
-				return nil, err
-			}
-			udpConn, err := net.ListenUDP("udp", &net.UDPAddr{IP: net.IPv4zero, Port: 0})
-			if err != nil {
-				return nil, err
-			}
-			return quic.DialEarlyContext(ctx, udpConn, remoteAddr, host, tlsCfg, cfg)
-		}
 	}
 	return r
 }
 
 type dohResolver struct {
-	endpoint     string
+	endpoint          string
-	isDoH3       bool
+	isDoH3            bool
-	doh3DialFunc func(ctx context.Context, addr string, tlsCfg *tls.Config, cfg *quic.Config) (quic.EarlyConnection, error)
+	transport         *http.Transport
-	transport    *http.Transport
+	http3RoundTripper *http3.RoundTripper
 }
 
 func (r *dohResolver) Resolve(ctx context.Context, msg *dns.Msg) (*dns.Msg, error) {
@@ -66,9 +44,7 @@ func (r *dohResolver) Resolve(ctx context.Context, msg *dns.Msg) (*dns.Msg, erro
 
 	c := http.Client{Transport: r.transport}
 	if r.isDoH3 {
-		c.Transport = &http3.RoundTripper{}
+		c.Transport = r.http3RoundTripper
-		c.Transport.(*http3.RoundTripper).Dial = r.doh3DialFunc
-		defer c.Transport.(*http3.RoundTripper).Close()
 	}
 	resp, err := c.Do(req)
 	if err != nil {