Move captive portals config to a dedicated section

Add examples

dnscrypt-proxy/coldstart.go

@@ -59,11 +59,13 @@ func HandleCaptivePortalQuery(msg *dns.Msg, question *dns.Question, ips *Captive
 		}
 	} else if question.Qtype == dns.TypeAAAA {
 		for _, xip := range *ips {
-			if ip := xip.To16(); ip != nil {
-				rr := new(dns.AAAA)
-				rr.Hdr = dns.RR_Header{Name: question.Name, Rrtype: dns.TypeAAAA, Class: dns.ClassINET, Ttl: ttl}
-				rr.AAAA = ip
-				respMsg.Answer = append(respMsg.Answer, rr)
+			if xip.To4() == nil {
+				if ip := xip.To16(); ip != nil {
+					rr := new(dns.AAAA)
+					rr.Hdr = dns.RR_Header{Name: question.Name, Rrtype: dns.TypeAAAA, Class: dns.ClassINET, Ttl: ttl}
+					rr.AAAA = ip
+					respMsg.Answer = append(respMsg.Answer, rr)
+				}
 			}
 		}
 	} else if question.Qtype == dns.TypeHTTPS {
@@ -154,10 +156,10 @@ func addColdStartListener(proxy *Proxy, ipsMap *CaptivePortalMap, listenAddrStr
 }
 
 func ColdStart(proxy *Proxy) (*CaptivePortalHandler, error) {
-	if len(proxy.captivePortalFile) == 0 {
+	if len(proxy.captivePortalMapFile) == 0 {
 		return nil, nil
 	}
-	bin, err := ReadTextFile(proxy.captivePortalFile)
+	bin, err := ReadTextFile(proxy.captivePortalMapFile)
 	if err != nil {
 		dlog.Warn(err)
 		return nil, err

dnscrypt-proxy/config.go

@@ -70,7 +70,7 @@ type Config struct {
 	AllowIP                  AllowIPConfig               `toml:"allowed_ips"`
 	ForwardFile              string                      `toml:"forwarding_rules"`
 	CloakFile                string                      `toml:"cloaking_rules"`
-	CaptivePortalFile        string                      `toml:"captive_portal_handler"`
+	CaptivePortals           CaptivePortalsConfig        `toml:"captive_portals"`
 	StaticsConfig            map[string]StaticConfig     `toml:"static"`
 	SourcesConfig            map[string]SourceConfig     `toml:"sources"`
 	BrokenImplementations    BrokenImplementationsConfig `toml:"broken_implementations"`
@@ -272,6 +272,10 @@ type DNS64Config struct {
 	Resolvers []string `toml:"resolver"`
 }
 
+type CaptivePortalsConfig struct {
+	MapFile string `toml:"map_file"`
+}
+
 type ConfigFlags struct {
 	List                    *bool
 	ListAll                 *bool
@@ -579,7 +583,7 @@ func ConfigLoad(proxy *Proxy, flags *ConfigFlags) error {
 
 	proxy.forwardFile = config.ForwardFile
 	proxy.cloakFile = config.CloakFile
-	proxy.captivePortalFile = config.CaptivePortalFile
+	proxy.captivePortalMapFile = config.CaptivePortals.MapFile
 
 	allWeeklyRanges, err := ParseAllWeeklyRanges(config.AllWeeklyRanges)
 	if err != nil {

dnscrypt-proxy/example-captive-portal-handler.txt

@@ -1,7 +0,0 @@
-captive.apple.com               17.253.109.201,17.253.113.202
-connectivitycheck.gstatic.com   64.233.165.94
-connectivitycheck.android.com   172.217.20.110
-www.msftncsi.com                2.19.98.8,2.19.98.59
-dns.msftncsi.com                131.107.255.255
-www.msftconnecttest.com         13.107.4.52
-ipv4only.arpa                   192.0.0.170,192.0.0.171

dnscrypt-proxy/example-dnscrypt-proxy.toml

@@ -346,6 +346,7 @@ reject_ttl = 600
 # cloak_ttl = 600
 
 
+
 ###########################
 #        DNS cache        #
 ###########################
@@ -381,6 +382,20 @@ cache_neg_max_ttl = 600
 
 
 
+########################################
+#        Captive portal handling       #
+########################################
+
+[captive_portals]
+
+## A file that contains a set of names used by operating systems to
+## check for connectivity and captive portals, along with hard-coded
+## IP addresses to return.
+
+map_file = "example-captive-portals.txt"
+
+
+
 ##################################
 #        Local DoH server        #
 ##################################

dnscrypt-proxy/main.go

@@ -15,7 +15,7 @@ import (
 )
 
 const (
-	AppVersion            = "2.0.44"
+	AppVersion            = "2.0.45"
 	DefaultConfigFileName = "dnscrypt-proxy.toml"
 )
 

dnscrypt-proxy/plugin_captive_portal.go

@@ -19,6 +19,7 @@ func (plugin *PluginCaptivePortal) Description() string {
 
 func (plugin *PluginCaptivePortal) Init(proxy *Proxy) error {
 	plugin.captivePortalMap = proxy.captivePortalMap
+	dlog.Notice("Captive portals handler enabled")
 	return nil
 }
 

dnscrypt-proxy/proxy.go

@@ -44,7 +44,7 @@ type Proxy struct {
 	nxLogFormat                    string
 	localDoHCertFile               string
 	localDoHCertKeyFile            string
-	captivePortalFile              string
+	captivePortalMapFile           string
 	localDoHPath                   string
 	mainProto                      string
 	cloakFile                      string