AdGuardHome/internal/home/dns.go

400 lines
9.7 KiB
Go

package home
import (
"fmt"
"net"
"os"
"path/filepath"
"github.com/AdguardTeam/AdGuardHome/internal/agherr"
"github.com/AdguardTeam/AdGuardHome/internal/dnsfilter"
"github.com/AdguardTeam/AdGuardHome/internal/dnsforward"
"github.com/AdguardTeam/AdGuardHome/internal/querylog"
"github.com/AdguardTeam/AdGuardHome/internal/stats"
"github.com/AdguardTeam/AdGuardHome/internal/util"
"github.com/AdguardTeam/dnsproxy/proxy"
"github.com/AdguardTeam/golibs/log"
"github.com/ameshkov/dnscrypt/v2"
yaml "gopkg.in/yaml.v2"
)
// 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 {
var err error
baseDir := Context.getDataDir()
statsConf := stats.Config{
Filename: filepath.Join(baseDir, "stats.db"),
LimitDays: config.DNS.StatsInterval,
AnonymizeClientIP: config.DNS.AnonymizeClientIP,
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,
FileEnabled: config.DNS.QueryLogFileEnabled,
BaseDir: baseDir,
Interval: config.DNS.QueryLogInterval,
MemSize: config.DNS.QueryLogMemSize,
AnonymizeClientIP: config.DNS.AnonymizeClientIP,
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.AutoHosts = &Context.autoHosts
filterConf.ConfigModified = onConfigModified
filterConf.HTTPRegister = httpRegister
Context.dnsFilter = dnsfilter.New(&filterConf, nil)
p := dnsforward.DNSCreateParams{
DNSFilter: Context.dnsFilter,
Stats: Context.stats,
QueryLog: Context.queryLog,
}
if Context.dhcpServer != nil {
p.DHCPServer = Context.dhcpServer
}
Context.dnsServer = dnsforward.NewServer(p)
Context.clients.dnsServer = Context.dnsServer
dnsConfig, err := generateServerConfig()
if err != nil {
closeDNSServer()
return fmt.Errorf("generateServerConfig: %w", err)
}
err = Context.dnsServer.Prepare(&dnsConfig)
if err != nil {
closeDNSServer()
return fmt.Errorf("dnsServer.Prepare: %w", err)
}
Context.rdns = InitRDNS(Context.dnsServer, &Context.clients)
Context.whois = initWhois(&Context.clients)
Context.filters.Init()
return nil
}
func isRunning() bool {
return Context.dnsServer != nil && Context.dnsServer.IsRunning()
}
func onDNSRequest(d *proxy.DNSContext) {
ip := dnsforward.IPStringFromAddr(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 !Context.ipDetector.detectSpecialNetwork(ipAddr) {
Context.whois.Begin(ip)
}
}
func generateServerConfig() (newconfig dnsforward.ServerConfig, err error) {
bindHost := net.ParseIP(config.DNS.BindHost)
newconfig = dnsforward.ServerConfig{
UDPListenAddr: &net.UDPAddr{IP: bindHost, Port: config.DNS.Port},
TCPListenAddr: &net.TCPAddr{IP: bindHost, Port: config.DNS.Port},
FilteringConfig: config.DNS.FilteringConfig,
ConfigModified: onConfigModified,
HTTPRegister: httpRegister,
OnDNSRequest: onDNSRequest,
}
tlsConf := tlsConfigSettings{}
Context.tls.WriteDiskConfig(&tlsConf)
if tlsConf.Enabled {
newconfig.TLSConfig = tlsConf.TLSConfig
if tlsConf.PortDNSOverTLS != 0 {
newconfig.TLSListenAddr = &net.TCPAddr{
IP: bindHost,
Port: tlsConf.PortDNSOverTLS,
}
}
if tlsConf.PortDNSOverQUIC != 0 {
newconfig.QUICListenAddr = &net.UDPAddr{
IP: bindHost,
Port: int(tlsConf.PortDNSOverQUIC),
}
}
if tlsConf.PortDNSCrypt != 0 {
newconfig.DNSCryptConfig, err = newDNSCrypt(bindHost, tlsConf)
if err != nil {
// Don't wrap the error, because it's already
// wrapped by newDNSCrypt.
return dnsforward.ServerConfig{}, err
}
}
}
newconfig.TLSv12Roots = Context.tlsRoots
newconfig.TLSCiphers = Context.tlsCiphers
newconfig.TLSAllowUnencryptedDOH = tlsConf.AllowUnencryptedDOH
newconfig.FilterHandler = applyAdditionalFiltering
newconfig.GetCustomUpstreamByClient = Context.clients.FindUpstreams
return newconfig, nil
}
func newDNSCrypt(bindHost net.IP, tlsConf tlsConfigSettings) (dnscc dnsforward.DNSCryptConfig, err error) {
if tlsConf.DNSCryptConfigFile == "" {
return dnscc, agherr.Error("no dnscrypt_config_file")
}
f, err := os.Open(tlsConf.DNSCryptConfigFile)
if err != nil {
return dnscc, fmt.Errorf("opening dnscrypt config: %w", err)
}
defer f.Close()
rc := &dnscrypt.ResolverConfig{}
err = yaml.NewDecoder(f).Decode(rc)
if err != nil {
return dnscc, fmt.Errorf("decoding dnscrypt config: %w", err)
}
cert, err := rc.CreateCert()
if err != nil {
return dnscc, fmt.Errorf("creating dnscrypt cert: %w", err)
}
udpAddr := &net.UDPAddr{
IP: bindHost,
Port: tlsConf.PortDNSCrypt,
}
tcpAddr := &net.TCPAddr{
IP: bindHost,
Port: tlsConf.PortDNSCrypt,
}
return dnsforward.DNSCryptConfig{
UDPListenAddr: udpAddr,
TCPListenAddr: tcpAddr,
ResolverCert: cert,
ProviderName: rc.ProviderName,
Enabled: true,
}, nil
}
type dnsEncryption struct {
https string
tls string
quic string
}
func getDNSEncryption() dnsEncryption {
dnsEncryption := dnsEncryption{}
tlsConf := tlsConfigSettings{}
Context.tls.WriteDiskConfig(&tlsConf)
if tlsConf.Enabled && len(tlsConf.ServerName) != 0 {
if tlsConf.PortHTTPS != 0 {
addr := tlsConf.ServerName
if tlsConf.PortHTTPS != 443 {
addr = fmt.Sprintf("%s:%d", addr, tlsConf.PortHTTPS)
}
addr = fmt.Sprintf("https://%s/dns-query", addr)
dnsEncryption.https = addr
}
if tlsConf.PortDNSOverTLS != 0 {
addr := fmt.Sprintf("tls://%s:%d", tlsConf.ServerName, tlsConf.PortDNSOverTLS)
dnsEncryption.tls = addr
}
if tlsConf.PortDNSOverQUIC != 0 {
addr := fmt.Sprintf("quic://%s:%d", tlsConf.ServerName, tlsConf.PortDNSOverQUIC)
dnsEncryption.quic = addr
}
}
return dnsEncryption
}
// Get the list of DNS addresses the server is listening on
func getDNSAddresses() []string {
dnsAddresses := []string{}
if config.DNS.BindHost == "0.0.0.0" {
ifaces, e := util.GetValidNetInterfacesForWeb()
if e != nil {
log.Error("Couldn't get network interfaces: %v", e)
return []string{}
}
for _, iface := range ifaces {
for _, addr := range iface.Addresses {
addDNSAddress(&dnsAddresses, addr)
}
}
} else {
addDNSAddress(&dnsAddresses, config.DNS.BindHost)
}
dnsEncryption := getDNSEncryption()
if dnsEncryption.https != "" {
dnsAddresses = append(dnsAddresses, dnsEncryption.https)
}
if dnsEncryption.tls != "" {
dnsAddresses = append(dnsAddresses, dnsEncryption.tls)
}
if dnsEncryption.quic != "" {
dnsAddresses = append(dnsAddresses, dnsEncryption.quic)
}
return dnsAddresses
}
// If a client has his own settings, apply them
func applyAdditionalFiltering(clientAddr string, setts *dnsfilter.RequestFilteringSettings) {
Context.dnsFilter.ApplyBlockedServices(setts, nil, true)
if len(clientAddr) == 0 {
return
}
setts.ClientIP = clientAddr
c, ok := Context.clients.Find(clientAddr)
if !ok {
return
}
log.Debug("Using settings for client %s with IP %s", c.Name, clientAddr)
if c.UseOwnBlockedServices {
Context.dnsFilter.ApplyBlockedServices(setts, c.BlockedServices, false)
}
setts.ClientName = c.Name
setts.ClientTags = c.Tags
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)
Context.clients.Start()
err := Context.dnsServer.Start()
if err != nil {
return fmt.Errorf("couldn't start forwarding DNS server: %w", err)
}
Context.dnsFilter.Start()
Context.filters.Start()
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 !Context.ipDetector.detectSpecialNetwork(ipAddr) {
Context.whois.Begin(ip)
}
}
return nil
}
func reconfigureDNSServer() (err error) {
var newconfig dnsforward.ServerConfig
newconfig, err = generateServerConfig()
if err != nil {
return fmt.Errorf("generating forwarding dns server config: %w", err)
}
err = Context.dnsServer.Reconfigure(&newconfig)
if err != nil {
return fmt.Errorf("starting forwarding dns server: %w", err)
}
return nil
}
func stopDNSServer() error {
if !isRunning() {
return nil
}
err := Context.dnsServer.Stop()
if err != nil {
return fmt.Errorf("couldn't stop forwarding DNS server: %w", err)
}
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
}
Context.filters.Close()
log.Debug("Closed all DNS modules")
}