package home import ( "fmt" "net" "net/netip" "net/url" "os" "path/filepath" "time" "github.com/AdguardTeam/AdGuardHome/internal/aghalg" "github.com/AdguardTeam/AdGuardHome/internal/aghhttp" "github.com/AdguardTeam/AdGuardHome/internal/aghnet" "github.com/AdguardTeam/AdGuardHome/internal/client" "github.com/AdguardTeam/AdGuardHome/internal/dnsforward" "github.com/AdguardTeam/AdGuardHome/internal/filtering" "github.com/AdguardTeam/AdGuardHome/internal/querylog" "github.com/AdguardTeam/AdGuardHome/internal/stats" "github.com/AdguardTeam/golibs/errors" "github.com/AdguardTeam/golibs/log" "github.com/AdguardTeam/golibs/netutil" "github.com/ameshkov/dnscrypt/v2" yaml "gopkg.in/yaml.v3" ) // Default listening ports. const ( defaultPortDNS uint16 = 53 defaultPortHTTP uint16 = 80 defaultPortHTTPS uint16 = 443 defaultPortQUIC uint16 = 853 defaultPortTLS uint16 = 853 ) // Called by other modules when configuration is changed func onConfigModified() { err := config.write() if err != nil { log.Error("writing config: %s", err) } } // initDNS updates all the fields of the [Context] needed to initialize the DNS // server and initializes it at last. It also must not be called unless // [config] and [Context] are initialized. func initDNS() (err error) { anonymizer := config.anonymizer() statsDir, querylogDir, err := checkStatsAndQuerylogDirs(&Context, config) if err != nil { return err } statsConf := stats.Config{ Filename: filepath.Join(statsDir, "stats.db"), Limit: config.Stats.Interval.Duration, ConfigModified: onConfigModified, HTTPRegister: httpRegister, Enabled: config.Stats.Enabled, ShouldCountClient: Context.clients.shouldCountClient, } engine, err := aghnet.NewIgnoreEngine(config.Stats.Ignored) if err != nil { return fmt.Errorf("statistics: ignored list: %w", err) } statsConf.Ignored = engine Context.stats, err = stats.New(statsConf) if err != nil { return fmt.Errorf("init stats: %w", err) } conf := querylog.Config{ Anonymizer: anonymizer, ConfigModified: onConfigModified, HTTPRegister: httpRegister, FindClient: Context.clients.findMultiple, BaseDir: querylogDir, AnonymizeClientIP: config.DNS.AnonymizeClientIP, RotationIvl: config.QueryLog.Interval.Duration, MemSize: config.QueryLog.MemSize, Enabled: config.QueryLog.Enabled, FileEnabled: config.QueryLog.FileEnabled, } engine, err = aghnet.NewIgnoreEngine(config.QueryLog.Ignored) if err != nil { return fmt.Errorf("querylog: ignored list: %w", err) } conf.Ignored = engine Context.queryLog, err = querylog.New(conf) if err != nil { return fmt.Errorf("init querylog: %w", err) } Context.filters, err = filtering.New(config.Filtering, nil) if err != nil { // Don't wrap the error, since it's informative enough as is. return err } tlsConf := &tlsConfigSettings{} Context.tls.WriteDiskConfig(tlsConf) return initDNSServer( Context.filters, Context.stats, Context.queryLog, Context.dhcpServer, anonymizer, httpRegister, tlsConf, ) } // initDNSServer initializes the [context.dnsServer]. To only use the internal // proxy, none of the arguments are required, but tlsConf still must not be nil, // in other cases all the arguments also must not be nil. It also must not be // called unless [config] and [Context] are initialized. func initDNSServer( filters *filtering.DNSFilter, sts stats.Interface, qlog querylog.QueryLog, dhcpSrv dnsforward.DHCP, anonymizer *aghnet.IPMut, httpReg aghhttp.RegisterFunc, tlsConf *tlsConfigSettings, ) (err error) { Context.dnsServer, err = dnsforward.NewServer(dnsforward.DNSCreateParams{ DNSFilter: filters, Stats: sts, QueryLog: qlog, PrivateNets: parseSubnetSet(config.DNS.PrivateNets), Anonymizer: anonymizer, DHCPServer: dhcpSrv, EtcHosts: Context.etcHosts, LocalDomain: config.DHCP.LocalDomainName, }) defer func() { if err != nil { closeDNSServer() } }() if err != nil { return fmt.Errorf("dnsforward.NewServer: %w", err) } Context.clients.clientChecker = Context.dnsServer dnsConf, err := newServerConfig(&config.DNS, config.Clients.Sources, tlsConf, httpReg) if err != nil { return fmt.Errorf("newServerConfig: %w", err) } // Try to prepare the server with disabled private RDNS resolution if it // failed to prepare as is. See TODO on [dnsforward.PrivateRDNSError]. err = Context.dnsServer.Prepare(dnsConf) if privRDNSErr := (&dnsforward.PrivateRDNSError{}); errors.As(err, &privRDNSErr) { log.Info("WARNING: %s; trying to disable private RDNS resolution", err) dnsConf.UsePrivateRDNS = false err = Context.dnsServer.Prepare(dnsConf) } if err != nil { return fmt.Errorf("dnsServer.Prepare: %w", err) } return nil } // parseSubnetSet parses a slice of subnets. If the slice is empty, it returns // a subnet set that matches all locally served networks, see // [netutil.IsLocallyServed]. func parseSubnetSet(nets []netutil.Prefix) (s netutil.SubnetSet) { switch len(nets) { case 0: // Use an optimized function-based matcher. return netutil.SubnetSetFunc(netutil.IsLocallyServed) case 1: return nets[0].Prefix default: return netutil.SliceSubnetSet(netutil.UnembedPrefixes(nets)) } } func isRunning() bool { return Context.dnsServer != nil && Context.dnsServer.IsRunning() } func ipsToTCPAddrs(ips []netip.Addr, port uint16) (tcpAddrs []*net.TCPAddr) { if ips == nil { return nil } tcpAddrs = make([]*net.TCPAddr, 0, len(ips)) for _, ip := range ips { tcpAddrs = append(tcpAddrs, net.TCPAddrFromAddrPort(netip.AddrPortFrom(ip, port))) } return tcpAddrs } func ipsToUDPAddrs(ips []netip.Addr, port uint16) (udpAddrs []*net.UDPAddr) { if ips == nil { return nil } udpAddrs = make([]*net.UDPAddr, 0, len(ips)) for _, ip := range ips { udpAddrs = append(udpAddrs, net.UDPAddrFromAddrPort(netip.AddrPortFrom(ip, port))) } return udpAddrs } // newServerConfig converts values from the configuration file into the internal // DNS server configuration. All arguments must not be nil. func newServerConfig( dnsConf *dnsConfig, clientSrcConf *clientSourcesConfig, tlsConf *tlsConfigSettings, httpReg aghhttp.RegisterFunc, ) (newConf *dnsforward.ServerConfig, err error) { hosts := aghalg.CoalesceSlice(dnsConf.BindHosts, []netip.Addr{netutil.IPv4Localhost()}) fwdConf := dnsConf.Config fwdConf.FilterHandler = applyAdditionalFiltering fwdConf.ClientsContainer = &Context.clients newConf = &dnsforward.ServerConfig{ UDPListenAddrs: ipsToUDPAddrs(hosts, dnsConf.Port), TCPListenAddrs: ipsToTCPAddrs(hosts, dnsConf.Port), Config: fwdConf, TLSConfig: newDNSTLSConfig(tlsConf, hosts), TLSAllowUnencryptedDoH: tlsConf.AllowUnencryptedDoH, UpstreamTimeout: dnsConf.UpstreamTimeout.Duration, TLSv12Roots: Context.tlsRoots, ConfigModified: onConfigModified, HTTPRegister: httpReg, LocalPTRResolvers: dnsConf.PrivateRDNSResolvers, UseDNS64: dnsConf.UseDNS64, DNS64Prefixes: dnsConf.DNS64Prefixes, UsePrivateRDNS: dnsConf.UsePrivateRDNS, ServeHTTP3: dnsConf.ServeHTTP3, UseHTTP3Upstreams: dnsConf.UseHTTP3Upstreams, ServePlainDNS: dnsConf.ServePlainDNS, } var initialAddresses []netip.Addr // Context.stats may be nil here if initDNSServer is called from // [cmdlineUpdate]. if sts := Context.stats; sts != nil { const initialClientsNum = 100 initialAddresses = Context.stats.TopClientsIP(initialClientsNum) } // Do not set DialContext, PrivateSubnets, and UsePrivateRDNS, because they // are set by [dnsforward.Server.Prepare]. newConf.AddrProcConf = &client.DefaultAddrProcConfig{ Exchanger: Context.dnsServer, AddressUpdater: &Context.clients, InitialAddresses: initialAddresses, CatchPanics: true, UseRDNS: clientSrcConf.RDNS, UseWHOIS: clientSrcConf.WHOIS, } newConf.DNSCryptConfig, err = newDNSCryptConfig(tlsConf, hosts) if err != nil { // Don't wrap the error, because it's already wrapped by // newDNSCryptConfig. return nil, err } return newConf, nil } // newDNSTLSConfig converts values from the configuration file into the internal // TLS settings for the DNS server. tlsConf must not be nil. func newDNSTLSConfig(conf *tlsConfigSettings, addrs []netip.Addr) (dnsConf dnsforward.TLSConfig) { if !conf.Enabled { return dnsforward.TLSConfig{} } dnsConf = conf.TLSConfig dnsConf.ServerName = conf.ServerName if conf.PortHTTPS != 0 { dnsConf.HTTPSListenAddrs = ipsToTCPAddrs(addrs, conf.PortHTTPS) } if conf.PortDNSOverTLS != 0 { dnsConf.TLSListenAddrs = ipsToTCPAddrs(addrs, conf.PortDNSOverTLS) } if conf.PortDNSOverQUIC != 0 { dnsConf.QUICListenAddrs = ipsToUDPAddrs(addrs, conf.PortDNSOverQUIC) } return dnsConf } // newDNSCryptConfig converts values from the configuration file into the // internal DNSCrypt settings for the DNS server. conf must not be nil. func newDNSCryptConfig( conf *tlsConfigSettings, addrs []netip.Addr, ) (dnsCryptConf dnsforward.DNSCryptConfig, err error) { if !conf.Enabled || conf.PortDNSCrypt == 0 { return dnsforward.DNSCryptConfig{}, nil } if conf.DNSCryptConfigFile == "" { return dnsforward.DNSCryptConfig{}, errors.Error("no dnscrypt_config_file") } f, err := os.Open(conf.DNSCryptConfigFile) if err != nil { return dnsforward.DNSCryptConfig{}, fmt.Errorf("opening dnscrypt config: %w", err) } defer func() { err = errors.WithDeferred(err, f.Close()) }() rc := &dnscrypt.ResolverConfig{} err = yaml.NewDecoder(f).Decode(rc) if err != nil { return dnsforward.DNSCryptConfig{}, fmt.Errorf("decoding dnscrypt config: %w", err) } cert, err := rc.CreateCert() if err != nil { return dnsforward.DNSCryptConfig{}, fmt.Errorf("creating dnscrypt cert: %w", err) } return dnsforward.DNSCryptConfig{ ResolverCert: cert, ProviderName: rc.ProviderName, UDPListenAddrs: ipsToUDPAddrs(addrs, conf.PortDNSCrypt), TCPListenAddrs: ipsToTCPAddrs(addrs, conf.PortDNSCrypt), Enabled: true, }, nil } type dnsEncryption struct { https string tls string quic string } func getDNSEncryption() (de dnsEncryption) { tlsConf := tlsConfigSettings{} Context.tls.WriteDiskConfig(&tlsConf) if !tlsConf.Enabled || len(tlsConf.ServerName) == 0 { return dnsEncryption{} } hostname := tlsConf.ServerName if tlsConf.PortHTTPS != 0 { addr := hostname if p := tlsConf.PortHTTPS; p != defaultPortHTTPS { addr = netutil.JoinHostPort(addr, p) } de.https = (&url.URL{ Scheme: "https", Host: addr, Path: "/dns-query", }).String() } if p := tlsConf.PortDNSOverTLS; p != 0 { de.tls = (&url.URL{ Scheme: "tls", Host: netutil.JoinHostPort(hostname, p), }).String() } if p := tlsConf.PortDNSOverQUIC; p != 0 { de.quic = (&url.URL{ Scheme: "quic", Host: netutil.JoinHostPort(hostname, p), }).String() } return de } // applyAdditionalFiltering adds additional client information and settings if // the client has them. func applyAdditionalFiltering(clientIP netip.Addr, clientID string, setts *filtering.Settings) { // pref is a prefix for logging messages around the scope. const pref = "applying filters" Context.filters.ApplyBlockedServices(setts) log.Debug("%s: looking for client with ip %s and clientid %q", pref, clientIP, clientID) if !clientIP.IsValid() { return } setts.ClientIP = clientIP c, ok := Context.clients.find(clientID) if !ok { c, ok = Context.clients.find(clientIP.String()) if !ok { log.Debug("%s: no clients with ip %s and clientid %q", pref, clientIP, clientID) return } } log.Debug("%s: using settings for client %q (%s; %q)", pref, c.Name, clientIP, clientID) if c.UseOwnBlockedServices { // TODO(e.burkov): Get rid of this crutch. setts.ServicesRules = nil svcs := c.BlockedServices.IDs if !c.BlockedServices.Schedule.Contains(time.Now()) { Context.filters.ApplyBlockedServicesList(setts, svcs) log.Debug("%s: services for client %q set: %s", pref, c.Name, svcs) } } setts.ClientName = c.Name setts.ClientTags = c.Tags if !c.UseOwnSettings { return } setts.FilteringEnabled = c.FilteringEnabled setts.SafeSearchEnabled = c.SafeSearchConf.Enabled setts.ClientSafeSearch = c.SafeSearch setts.SafeBrowsingEnabled = c.SafeBrowsingEnabled setts.ParentalEnabled = c.ParentalEnabled } func startDNSServer() error { config.RLock() defer config.RUnlock() if isRunning() { return fmt.Errorf("unable to start forwarding DNS server: Already running") } Context.filters.EnableFilters(false) Context.clients.Start() err := Context.dnsServer.Start() if err != nil { return fmt.Errorf("couldn't start forwarding DNS server: %w", err) } Context.filters.Start() Context.stats.Start() Context.queryLog.Start() return nil } func reconfigureDNSServer() (err error) { tlsConf := &tlsConfigSettings{} Context.tls.WriteDiskConfig(tlsConf) newConf, err := newServerConfig(&config.DNS, config.Clients.Sources, tlsConf, httpRegister) if err != nil { return fmt.Errorf("generating forwarding dns server config: %w", err) } err = Context.dnsServer.Reconfigure(newConf) if err != nil { return fmt.Errorf("starting forwarding dns server: %w", err) } return nil } func stopDNSServer() (err error) { if !isRunning() { return nil } err = Context.dnsServer.Stop() if err != nil { return fmt.Errorf("stopping forwarding dns server: %w", err) } err = Context.clients.close() if err != nil { return fmt.Errorf("closing clients container: %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.filters != nil { Context.filters.Close() } if Context.stats != nil { err := Context.stats.Close() if err != nil { log.Debug("closing stats: %s", err) } } if Context.queryLog != nil { Context.queryLog.Close() } log.Debug("all dns modules are closed") } // checkStatsAndQuerylogDirs checks and returns directory paths to store // statistics and query log. func checkStatsAndQuerylogDirs( ctx *homeContext, conf *configuration, ) (statsDir, querylogDir string, err error) { baseDir := ctx.getDataDir() statsDir = conf.Stats.DirPath if statsDir == "" { statsDir = baseDir } else { err = checkDir(statsDir) if err != nil { return "", "", fmt.Errorf("statistics: custom directory: %w", err) } } querylogDir = conf.QueryLog.DirPath if querylogDir == "" { querylogDir = baseDir } else { err = checkDir(querylogDir) if err != nil { return "", "", fmt.Errorf("querylog: custom directory: %w", err) } } return statsDir, querylogDir, nil } // checkDir checks if the path is a directory. It's used to check for // misconfiguration at startup. func checkDir(path string) (err error) { var fi os.FileInfo if fi, err = os.Stat(path); err != nil { // Don't wrap the error, since it's informative enough as is. return err } if !fi.IsDir() { return fmt.Errorf("%q is not a directory", path) } return nil }