package home import ( "fmt" "net" "net/url" "os" "path/filepath" "strconv" "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/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{ ConfigModified: onConfigModified, HTTPRegister: httpRegister, FindClient: Context.clients.findMultiple, BaseDir: baseDir, RotationIvl: config.DNS.QueryLogInterval, MemSize: config.DNS.QueryLogMemSize, Enabled: config.DNS.QueryLogEnabled, FileEnabled: config.DNS.QueryLogFileEnabled, AnonymizeClientIP: config.DNS.AnonymizeClientIP, } Context.queryLog = querylog.New(conf) filterConf := config.DNS.DnsfilterConf filterConf.EtcHosts = Context.etcHosts filterConf.ConfigModified = onConfigModified filterConf.HTTPRegister = httpRegister Context.dnsFilter = dnsfilter.New(&filterConf, nil) p := dnsforward.DNSCreateParams{ DNSFilter: Context.dnsFilter, Stats: Context.stats, QueryLog: Context.queryLog, SubnetDetector: Context.subnetDetector, LocalDomain: config.DNS.LocalDomainName, } if Context.dhcpServer != nil { p.DHCPServer = Context.dhcpServer } Context.dnsServer, err = dnsforward.NewServer(p) if err != nil { closeDNSServer() return fmt.Errorf("dnsforward.NewServer: %w", err) } 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 = NewRDNS(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.IPFromAddr(d.Addr) if ip == nil { // This would be quite weird if we get here. return } if config.DNS.ResolveClients && !ip.IsLoopback() { Context.rdns.Begin(ip) } if !Context.subnetDetector.IsSpecialNetwork(ip) { Context.whois.Begin(ip) } } func ipsToTCPAddrs(ips []net.IP, port int) (tcpAddrs []*net.TCPAddr) { if ips == nil { return nil } tcpAddrs = make([]*net.TCPAddr, len(ips)) for i, ip := range ips { tcpAddrs[i] = &net.TCPAddr{ IP: ip, Port: port, } } return tcpAddrs } func ipsToUDPAddrs(ips []net.IP, port int) (udpAddrs []*net.UDPAddr) { if ips == nil { return nil } udpAddrs = make([]*net.UDPAddr, len(ips)) for i, ip := range ips { udpAddrs[i] = &net.UDPAddr{ IP: ip, Port: port, } } return udpAddrs } func generateServerConfig() (newConf dnsforward.ServerConfig, err error) { dnsConf := config.DNS hosts := dnsConf.BindHosts if len(hosts) == 0 { hosts = []net.IP{{127, 0, 0, 1}} } newConf = dnsforward.ServerConfig{ UDPListenAddrs: ipsToUDPAddrs(hosts, dnsConf.Port), TCPListenAddrs: ipsToTCPAddrs(hosts, dnsConf.Port), FilteringConfig: dnsConf.FilteringConfig, ConfigModified: onConfigModified, HTTPRegister: httpRegister, OnDNSRequest: onDNSRequest, } tlsConf := tlsConfigSettings{} Context.tls.WriteDiskConfig(&tlsConf) if tlsConf.Enabled { newConf.TLSConfig = tlsConf.TLSConfig newConf.TLSConfig.ServerName = tlsConf.ServerName if tlsConf.PortDNSOverTLS != 0 { newConf.TLSListenAddrs = ipsToTCPAddrs(hosts, tlsConf.PortDNSOverTLS) } if tlsConf.PortDNSOverQUIC != 0 { newConf.QUICListenAddrs = ipsToUDPAddrs(hosts, tlsConf.PortDNSOverQUIC) } if tlsConf.PortDNSCrypt != 0 { newConf.DNSCryptConfig, err = newDNSCrypt(hosts, tlsConf) if err != nil { // Don't wrap the error, because it's already // wrapped by newDNSCrypt. return dnsforward.ServerConfig{}, err } } } newConf.TLSv12Roots = Context.tlsRoots newConf.TLSCiphers = Context.tlsCiphers newConf.TLSAllowUnencryptedDOH = tlsConf.AllowUnencryptedDOH newConf.FilterHandler = applyAdditionalFiltering newConf.GetCustomUpstreamByClient = Context.clients.FindUpstreams newConf.ResolveClients = dnsConf.ResolveClients newConf.LocalPTRResolvers = dnsConf.LocalPTRResolvers return newConf, nil } func newDNSCrypt(hosts []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) } return dnsforward.DNSCryptConfig{ UDPListenAddrs: ipsToUDPAddrs(hosts, tlsConf.PortDNSCrypt), TCPListenAddrs: ipsToTCPAddrs(hosts, tlsConf.PortDNSCrypt), ResolverCert: cert, ProviderName: rc.ProviderName, 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 { hostname := tlsConf.ServerName if tlsConf.PortHTTPS != 0 { addr := hostname if tlsConf.PortHTTPS != 443 { addr = net.JoinHostPort(addr, strconv.Itoa(tlsConf.PortHTTPS)) } de.https = (&url.URL{ Scheme: "https", Host: addr, Path: "/dns-query", }).String() } if tlsConf.PortDNSOverTLS != 0 { de.tls = (&url.URL{ Scheme: "tls", Host: net.JoinHostPort(hostname, strconv.Itoa(tlsConf.PortDNSOverTLS)), }).String() } if tlsConf.PortDNSOverQUIC != 0 { de.quic = (&url.URL{ Scheme: "quic", Host: net.JoinHostPort(hostname, strconv.Itoa(int(tlsConf.PortDNSOverQUIC))), }).String() } } return de } // applyAdditionalFiltering adds additional client information and settings if // the client has them. func applyAdditionalFiltering(clientAddr net.IP, clientID string, setts *dnsfilter.FilteringSettings) { Context.dnsFilter.ApplyBlockedServices(setts, nil, true) if clientAddr == nil { return } setts.ClientIP = clientAddr c, ok := Context.clients.Find(clientID) if !ok { c, ok = Context.clients.Find(clientAddr.String()) if !ok { return } } log.Debug("using settings for client %s with ip %s and id %q", c.Name, clientAddr, clientID) 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 { config.Lock() defer config.Unlock() 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 for _, ip := range Context.stats.GetTopClientsIP(topClientsNumber) { if config.DNS.ResolveClients && !ip.IsLoopback() { Context.rdns.Begin(ip) } if !Context.subnetDetector.IsSpecialNetwork(ip) { Context.whois.Begin(ip) } } return nil } func reconfigureDNSServer() (err error) { var newConf dnsforward.ServerConfig newConf, err = generateServerConfig() 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() 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") }