AdGuardHome/home/dns.go

302 lines
7.3 KiB
Go

package home
import (
"fmt"
"net"
"os"
"path/filepath"
"github.com/AdguardTeam/AdGuardHome/dnsfilter"
"github.com/AdguardTeam/AdGuardHome/dnsforward"
"github.com/AdguardTeam/AdGuardHome/querylog"
"github.com/AdguardTeam/AdGuardHome/stats"
"github.com/AdguardTeam/dnsproxy/proxy"
"github.com/AdguardTeam/dnsproxy/upstream"
"github.com/AdguardTeam/golibs/log"
"github.com/joomcode/errorx"
)
// Called by other modules when configuration is changed
func onConfigModified() {
_ = config.write()
}
// initDNSServer creates an instance of the dnsforward.Server
// Please note that we must do it even if we don't start it
// so that we had access to the query log and the stats
func initDNSServer() error {
baseDir := config.getDataDir()
err := os.MkdirAll(baseDir, 0755)
if err != nil {
return fmt.Errorf("Cannot create DNS data dir at %s: %s", baseDir, err)
}
statsConf := stats.Config{
Filename: filepath.Join(baseDir, "stats.db"),
LimitDays: config.DNS.StatsInterval,
ConfigModified: onConfigModified,
HTTPRegister: httpRegister,
}
Context.stats, err = stats.New(statsConf)
if err != nil {
return fmt.Errorf("Couldn't initialize statistics module")
}
conf := querylog.Config{
Enabled: config.DNS.QueryLogEnabled,
BaseDir: baseDir,
Interval: config.DNS.QueryLogInterval,
MemSize: config.DNS.QueryLogMemSize,
ConfigModified: onConfigModified,
HTTPRegister: httpRegister,
}
Context.queryLog = querylog.New(conf)
filterConf := config.DNS.DnsfilterConf
bindhost := config.DNS.BindHost
if config.DNS.BindHost == "0.0.0.0" {
bindhost = "127.0.0.1"
}
filterConf.ResolverAddress = fmt.Sprintf("%s:%d", bindhost, config.DNS.Port)
filterConf.ConfigModified = onConfigModified
filterConf.HTTPRegister = httpRegister
Context.dnsFilter = dnsfilter.New(&filterConf, nil)
Context.dnsServer = dnsforward.NewServer(Context.dnsFilter, Context.stats, Context.queryLog)
dnsConfig := generateServerConfig()
err = Context.dnsServer.Prepare(&dnsConfig)
if err != nil {
closeDNSServer()
return fmt.Errorf("dnsServer.Prepare: %s", err)
}
sessFilename := filepath.Join(baseDir, "sessions.db")
config.auth = InitAuth(sessFilename, config.Users, config.WebSessionTTLHours*60*60)
if config.auth == nil {
closeDNSServer()
return fmt.Errorf("Couldn't initialize Auth module")
}
config.Users = nil
Context.rdns = InitRDNS(Context.dnsServer, &Context.clients)
Context.whois = initWhois(&Context.clients)
initFiltering()
return nil
}
func isRunning() bool {
return Context.dnsServer != nil && Context.dnsServer.IsRunning()
}
// nolint (gocyclo)
// Return TRUE if IP is within public Internet IP range
func isPublicIP(ip net.IP) bool {
ip4 := ip.To4()
if ip4 != nil {
switch ip4[0] {
case 0:
return false //software
case 10:
return false //private network
case 127:
return false //loopback
case 169:
if ip4[1] == 254 {
return false //link-local
}
case 172:
if ip4[1] >= 16 && ip4[1] <= 31 {
return false //private network
}
case 192:
if (ip4[1] == 0 && ip4[2] == 0) || //private network
(ip4[1] == 0 && ip4[2] == 2) || //documentation
(ip4[1] == 88 && ip4[2] == 99) || //reserved
(ip4[1] == 168) { //private network
return false
}
case 198:
if (ip4[1] == 18 || ip4[2] == 19) || //private network
(ip4[1] == 51 || ip4[2] == 100) { //documentation
return false
}
case 203:
if ip4[1] == 0 && ip4[2] == 113 { //documentation
return false
}
case 224:
if ip4[1] == 0 && ip4[2] == 0 { //multicast
return false
}
case 255:
if ip4[1] == 255 && ip4[2] == 255 && ip4[3] == 255 { //subnet
return false
}
}
} else {
if ip.IsLoopback() || ip.IsLinkLocalMulticast() || ip.IsLinkLocalUnicast() {
return false
}
}
return true
}
func onDNSRequest(d *proxy.DNSContext) {
ip := dnsforward.GetIPString(d.Addr)
if ip == "" {
// This would be quite weird if we get here
return
}
ipAddr := net.ParseIP(ip)
if !ipAddr.IsLoopback() {
Context.rdns.Begin(ip)
}
if isPublicIP(ipAddr) {
Context.whois.Begin(ip)
}
}
func generateServerConfig() dnsforward.ServerConfig {
newconfig := dnsforward.ServerConfig{
UDPListenAddr: &net.UDPAddr{IP: net.ParseIP(config.DNS.BindHost), Port: config.DNS.Port},
TCPListenAddr: &net.TCPAddr{IP: net.ParseIP(config.DNS.BindHost), Port: config.DNS.Port},
FilteringConfig: config.DNS.FilteringConfig,
ConfigModified: onConfigModified,
HTTPRegister: httpRegister,
OnDNSRequest: onDNSRequest,
}
if config.TLS.Enabled {
newconfig.TLSConfig = config.TLS.TLSConfig
if config.TLS.PortDNSOverTLS != 0 {
newconfig.TLSListenAddr = &net.TCPAddr{IP: net.ParseIP(config.DNS.BindHost), Port: config.TLS.PortDNSOverTLS}
}
}
newconfig.FilterHandler = applyAdditionalFiltering
newconfig.GetUpstreamsByClient = getUpstreamsByClient
return newconfig
}
func getUpstreamsByClient(clientAddr string) []upstream.Upstream {
return Context.clients.FindUpstreams(clientAddr)
}
// If a client has his own settings, apply them
func applyAdditionalFiltering(clientAddr string, setts *dnsfilter.RequestFilteringSettings) {
ApplyBlockedServices(setts, config.DNS.BlockedServices)
if len(clientAddr) == 0 {
return
}
c, ok := Context.clients.Find(clientAddr)
if !ok {
return
}
log.Debug("Using settings for client with IP %s", clientAddr)
if c.UseOwnBlockedServices {
ApplyBlockedServices(setts, c.BlockedServices)
}
if !c.UseOwnSettings {
return
}
setts.FilteringEnabled = c.FilteringEnabled
setts.SafeSearchEnabled = c.SafeSearchEnabled
setts.SafeBrowsingEnabled = c.SafeBrowsingEnabled
setts.ParentalEnabled = c.ParentalEnabled
}
func startDNSServer() error {
if isRunning() {
return fmt.Errorf("unable to start forwarding DNS server: Already running")
}
enableFilters(false)
err := Context.dnsServer.Start()
if err != nil {
return errorx.Decorate(err, "Couldn't start forwarding DNS server")
}
Context.dnsFilter.Start()
startFiltering()
Context.stats.Start()
Context.queryLog.Start()
const topClientsNumber = 100 // the number of clients to get
topClients := Context.stats.GetTopClientsIP(topClientsNumber)
for _, ip := range topClients {
ipAddr := net.ParseIP(ip)
if !ipAddr.IsLoopback() {
Context.rdns.Begin(ip)
}
if isPublicIP(ipAddr) {
Context.whois.Begin(ip)
}
}
return nil
}
func reconfigureDNSServer() error {
newconfig := generateServerConfig()
err := Context.dnsServer.Reconfigure(&newconfig)
if err != nil {
return errorx.Decorate(err, "Couldn't start forwarding DNS server")
}
return nil
}
func stopDNSServer() error {
if !isRunning() {
return nil
}
err := Context.dnsServer.Stop()
if err != nil {
return errorx.Decorate(err, "Couldn't stop forwarding DNS server")
}
closeDNSServer()
return nil
}
func closeDNSServer() {
// DNS forward module must be closed BEFORE stats or queryLog because it depends on them
if Context.dnsServer != nil {
Context.dnsServer.Close()
Context.dnsServer = nil
}
if Context.dnsFilter != nil {
Context.dnsFilter.Close()
Context.dnsFilter = nil
}
if Context.stats != nil {
Context.stats.Close()
Context.stats = nil
}
if Context.queryLog != nil {
Context.queryLog.Close()
Context.queryLog = nil
}
if config.auth != nil {
config.auth.Close()
config.auth = nil
}
log.Debug("Closed all DNS modules")
}