// Package home contains AdGuard Home's HTTP API methods. package home import ( "context" "crypto/tls" "crypto/x509" "fmt" "io/fs" "net" "net/http" "net/http/pprof" "net/url" "os" "os/signal" "path/filepath" "runtime" "sync" "syscall" "time" "github.com/AdguardTeam/AdGuardHome/internal/aghalg" "github.com/AdguardTeam/AdGuardHome/internal/aghnet" "github.com/AdguardTeam/AdGuardHome/internal/aghos" "github.com/AdguardTeam/AdGuardHome/internal/dhcpd" "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/AdGuardHome/internal/updater" "github.com/AdguardTeam/AdGuardHome/internal/version" "github.com/AdguardTeam/golibs/errors" "github.com/AdguardTeam/golibs/log" "github.com/AdguardTeam/golibs/netutil" "gopkg.in/natefinch/lumberjack.v2" ) const ( // Used in config to indicate that syslog or eventlog (win) should be used for logger output configSyslog = "syslog" ) // Global context type homeContext struct { // Modules // -- clients clientsContainer // per-client-settings module stats stats.Interface // statistics module queryLog querylog.QueryLog // query log module dnsServer *dnsforward.Server // DNS module rdns *RDNS // rDNS module whois *WHOIS // WHOIS module dnsFilter *filtering.DNSFilter // DNS filtering module dhcpServer *dhcpd.Server // DHCP module auth *Auth // HTTP authentication module filters Filtering // DNS filtering module web *Web // Web (HTTP, HTTPS) module tls *TLSMod // TLS module // etcHosts is an IP-hostname pairs set taken from system configuration // (e.g. /etc/hosts) files. etcHosts *aghnet.HostsContainer // hostsWatcher is the watcher to detect changes in the hosts files. hostsWatcher aghos.FSWatcher updater *updater.Updater // mux is our custom http.ServeMux. mux *http.ServeMux // Runtime properties // -- configFilename string // Config filename (can be overridden via the command line arguments) workDir string // Location of our directory, used to protect against CWD being somewhere else firstRun bool // if set to true, don't run any services except HTTP web interface, and serve only first-run html pidFileName string // PID file name. Empty if no PID file was created. disableUpdate bool // If set, don't check for updates controlLock sync.Mutex tlsRoots *x509.CertPool // list of root CAs for TLSv1.2 tlsCiphers []uint16 // list of TLS ciphers to use transport *http.Transport client *http.Client appSignalChannel chan os.Signal // Channel for receiving OS signals by the console app // runningAsService flag is set to true when options are passed from the service runner runningAsService bool } // getDataDir returns path to the directory where we store databases and filters func (c *homeContext) getDataDir() string { return filepath.Join(c.workDir, dataDir) } // Context - a global context object var Context homeContext // Main is the entry point func Main(clientBuildFS fs.FS) { // config can be specified, which reads options from there, but other command line flags have to override config values // therefore, we must do it manually instead of using a lib args := loadOptions() Context.appSignalChannel = make(chan os.Signal) signal.Notify(Context.appSignalChannel, syscall.SIGINT, syscall.SIGTERM, syscall.SIGHUP, syscall.SIGQUIT) go func() { for { sig := <-Context.appSignalChannel log.Info("Received signal %q", sig) switch sig { case syscall.SIGHUP: Context.clients.Reload() Context.tls.Reload() default: cleanup(context.Background()) cleanupAlways() os.Exit(0) } } }() if args.serviceControlAction != "" { handleServiceControlAction(args, clientBuildFS) return } // run the protection run(args, clientBuildFS) } func setupContext(args options) { Context.runningAsService = args.runningAsService Context.disableUpdate = args.disableUpdate || version.Channel() == version.ChannelDevelopment Context.firstRun = detectFirstRun() if Context.firstRun { log.Info("This is the first time AdGuard Home is launched") checkPermissions() } initConfig() Context.tlsRoots = LoadSystemRootCAs() Context.tlsCiphers = InitTLSCiphers() Context.transport = &http.Transport{ DialContext: customDialContext, Proxy: getHTTPProxy, TLSClientConfig: &tls.Config{ RootCAs: Context.tlsRoots, MinVersion: tls.VersionTLS12, }, } Context.client = &http.Client{ Timeout: time.Minute * 5, Transport: Context.transport, } if !Context.firstRun { // Do the upgrade if necessary. err := upgradeConfig() fatalOnError(err) if err = parseConfig(); err != nil { log.Error("parsing configuration file: %s", err) os.Exit(1) } if args.checkConfig { log.Info("configuration file is ok") os.Exit(0) } if !args.noEtcHosts && config.Clients.Sources.HostsFile { err = setupHostsContainer() fatalOnError(err) } } Context.mux = http.NewServeMux() } // logIfUnsupported logs a formatted warning if the error is one of the // unsupported errors and returns nil. If err is nil, logIfUnsupported returns // nil. Otherwise, it returns err. func logIfUnsupported(msg string, err error) (outErr error) { if errors.As(err, new(*aghos.UnsupportedError)) { log.Debug(msg, err) return nil } return err } // configureOS sets the OS-related configuration. func configureOS(conf *configuration) (err error) { osConf := conf.OSConfig if osConf == nil { return nil } if osConf.Group != "" { err = aghos.SetGroup(osConf.Group) err = logIfUnsupported("warning: setting group", err) if err != nil { return fmt.Errorf("setting group: %w", err) } log.Info("group set to %s", osConf.Group) } if osConf.User != "" { err = aghos.SetUser(osConf.User) err = logIfUnsupported("warning: setting user", err) if err != nil { return fmt.Errorf("setting user: %w", err) } log.Info("user set to %s", osConf.User) } if osConf.RlimitNoFile != 0 { err = aghos.SetRlimit(osConf.RlimitNoFile) err = logIfUnsupported("warning: setting rlimit", err) if err != nil { return fmt.Errorf("setting rlimit: %w", err) } log.Info("rlimit_nofile set to %d", osConf.RlimitNoFile) } return nil } // setupHostsContainer initializes the structures to keep up-to-date the hosts // provided by the OS. func setupHostsContainer() (err error) { Context.hostsWatcher, err = aghos.NewOSWritesWatcher() if err != nil { return fmt.Errorf("initing hosts watcher: %w", err) } Context.etcHosts, err = aghnet.NewHostsContainer( filtering.SysHostsListID, aghos.RootDirFS(), Context.hostsWatcher, aghnet.DefaultHostsPaths()..., ) if err != nil { cerr := Context.hostsWatcher.Close() if errors.Is(err, aghnet.ErrNoHostsPaths) && cerr == nil { log.Info("warning: initing hosts container: %s", err) return nil } return errors.WithDeferred(fmt.Errorf("initing hosts container: %w", err), cerr) } return nil } func setupConfig(args options) (err error) { config.DHCP.WorkDir = Context.workDir config.DHCP.HTTPRegister = httpRegister config.DHCP.ConfigModified = onConfigModified Context.dhcpServer, err = dhcpd.Create(config.DHCP) if Context.dhcpServer == nil || err != nil { // TODO(a.garipov): There are a lot of places in the code right // now which assume that the DHCP server can be nil despite this // condition. Inspect them and perhaps rewrite them to use // Enabled() instead. return fmt.Errorf("initing dhcp: %w", err) } Context.updater = updater.NewUpdater(&updater.Config{ Client: Context.client, Version: version.Version(), Channel: version.Channel(), GOARCH: runtime.GOARCH, GOOS: runtime.GOOS, GOARM: version.GOARM(), GOMIPS: version.GOMIPS(), WorkDir: Context.workDir, ConfName: config.getConfigFilename(), }) var arpdb aghnet.ARPDB if config.Clients.Sources.ARP { arpdb = aghnet.NewARPDB() } Context.clients.Init(config.Clients.Persistent, Context.dhcpServer, Context.etcHosts, arpdb) if args.bindPort != 0 { tcpPorts := aghalg.UniqChecker[tcpPort]{} addPorts(tcpPorts, tcpPort(args.bindPort), tcpPort(config.BetaBindPort)) udpPorts := aghalg.UniqChecker[udpPort]{} addPorts(udpPorts, udpPort(config.DNS.Port)) if config.TLS.Enabled { addPorts( tcpPorts, tcpPort(config.TLS.PortHTTPS), tcpPort(config.TLS.PortDNSOverTLS), tcpPort(config.TLS.PortDNSCrypt), ) addPorts(udpPorts, udpPort(config.TLS.PortDNSOverQUIC)) } if err = tcpPorts.Validate(); err != nil { return fmt.Errorf("validating tcp ports: %w", err) } else if err = udpPorts.Validate(); err != nil { return fmt.Errorf("validating udp ports: %w", err) } config.BindPort = args.bindPort } // override bind host/port from the console if args.bindHost != nil { config.BindHost = args.bindHost } if len(args.pidFile) != 0 && writePIDFile(args.pidFile) { Context.pidFileName = args.pidFile } return nil } func initWeb(args options, clientBuildFS fs.FS) (web *Web, err error) { var clientFS, clientBetaFS fs.FS if args.localFrontend { log.Info("warning: using local frontend files") clientFS = os.DirFS("build/static") clientBetaFS = os.DirFS("build2/static") } else { clientFS, err = fs.Sub(clientBuildFS, "build/static") if err != nil { return nil, fmt.Errorf("getting embedded client subdir: %w", err) } clientBetaFS, err = fs.Sub(clientBuildFS, "build2/static") if err != nil { return nil, fmt.Errorf("getting embedded beta client subdir: %w", err) } } webConf := webConfig{ firstRun: Context.firstRun, BindHost: config.BindHost, BindPort: config.BindPort, BetaBindPort: config.BetaBindPort, ReadTimeout: readTimeout, ReadHeaderTimeout: readHdrTimeout, WriteTimeout: writeTimeout, clientFS: clientFS, clientBetaFS: clientBetaFS, } web = CreateWeb(&webConf) if web == nil { return nil, fmt.Errorf("initializing web: %w", err) } return web, nil } func fatalOnError(err error) { if err != nil { log.Fatal(err) } } // run configures and starts AdGuard Home. func run(args options, clientBuildFS fs.FS) { var err error // configure config filename initConfigFilename(args) // configure working dir and config path initWorkingDir(args) // configure log level and output configureLogger(args) // Print the first message after logger is configured. log.Println(version.Full()) log.Debug("current working directory is %s", Context.workDir) if args.runningAsService { log.Info("AdGuard Home is running as a service") } setupContext(args) err = configureOS(config) fatalOnError(err) // clients package uses filtering package's static data (filtering.BlockedSvcKnown()), // so we have to initialize filtering's static data first, // but also avoid relying on automatic Go init() function filtering.InitModule() err = setupConfig(args) fatalOnError(err) if !Context.firstRun { // Save the updated config err = config.write() fatalOnError(err) if config.DebugPProf { mux := http.NewServeMux() mux.HandleFunc("/debug/pprof/", pprof.Index) mux.HandleFunc("/debug/pprof/cmdline", pprof.Cmdline) mux.HandleFunc("/debug/pprof/profile", pprof.Profile) mux.HandleFunc("/debug/pprof/symbol", pprof.Symbol) mux.HandleFunc("/debug/pprof/trace", pprof.Trace) go func() { log.Info("pprof: listening on localhost:6060") lerr := http.ListenAndServe("localhost:6060", mux) log.Error("Error while running the pprof server: %s", lerr) }() } } err = os.MkdirAll(Context.getDataDir(), 0o755) if err != nil { log.Fatalf("Cannot create DNS data dir at %s: %s", Context.getDataDir(), err) } sessFilename := filepath.Join(Context.getDataDir(), "sessions.db") GLMode = args.glinetMode var arl *authRateLimiter if config.AuthAttempts > 0 && config.AuthBlockMin > 0 { arl = newAuthRateLimiter( time.Duration(config.AuthBlockMin)*time.Minute, config.AuthAttempts, ) } else { log.Info("authratelimiter is disabled") } Context.auth = InitAuth( sessFilename, config.Users, config.WebSessionTTLHours*60*60, arl, ) if Context.auth == nil { log.Fatalf("Couldn't initialize Auth module") } config.Users = nil Context.tls = tlsCreate(config.TLS) if Context.tls == nil { log.Fatalf("Can't initialize TLS module") } Context.web, err = initWeb(args, clientBuildFS) fatalOnError(err) if !Context.firstRun { err = initDNSServer() fatalOnError(err) Context.tls.Start() go func() { serr := startDNSServer() if serr != nil { closeDNSServer() fatalOnError(serr) } }() if Context.dhcpServer != nil { err = Context.dhcpServer.Start() if err != nil { log.Error("starting dhcp server: %s", err) } } } Context.web.Start() // wait indefinitely for other go-routines to complete their job select {} } // StartMods initializes and starts the DNS server after installation. func StartMods() error { err := initDNSServer() if err != nil { return err } Context.tls.Start() err = startDNSServer() if err != nil { closeDNSServer() return err } return nil } // Check if the current user permissions are enough to run AdGuard Home func checkPermissions() { log.Info("Checking if AdGuard Home has necessary permissions") if ok, err := aghnet.CanBindPrivilegedPorts(); !ok || err != nil { log.Fatal("This is the first launch of AdGuard Home. You must run it as Administrator.") } // We should check if AdGuard Home is able to bind to port 53 err := aghnet.CheckPort("tcp", net.IP{127, 0, 0, 1}, defaultPortDNS) if err != nil { if errors.Is(err, os.ErrPermission) { log.Fatal(`Permission check failed. AdGuard Home is not allowed to bind to privileged ports (for instance, port 53). Please note, that this is crucial for a server to be able to use privileged ports. You have two options: 1. Run AdGuard Home with root privileges 2. On Linux you can grant the CAP_NET_BIND_SERVICE capability: https://github.com/AdguardTeam/AdGuardHome/wiki/Getting-Started#running-without-superuser`) } log.Info( "AdGuard failed to bind to port 53: %s\n\n"+ "Please note, that this is crucial for a DNS server to be able to use that port.", err, ) } log.Info("AdGuard Home can bind to port 53") } // Write PID to a file func writePIDFile(fn string) bool { data := fmt.Sprintf("%d", os.Getpid()) err := os.WriteFile(fn, []byte(data), 0o644) if err != nil { log.Error("Couldn't write PID to file %s: %v", fn, err) return false } return true } func initConfigFilename(args options) { // config file path can be overridden by command-line arguments: if args.configFilename != "" { Context.configFilename = args.configFilename } else { // Default config file name Context.configFilename = "AdGuardHome.yaml" } } // initWorkingDir initializes the workDir // if no command-line arguments specified, we use the directory where our binary file is located func initWorkingDir(args options) { execPath, err := os.Executable() if err != nil { panic(err) } if args.workDir != "" { // If there is a custom config file, use it's directory as our working dir Context.workDir = args.workDir } else { Context.workDir = filepath.Dir(execPath) } workDir, err := filepath.EvalSymlinks(Context.workDir) if err != nil { panic(err) } Context.workDir = workDir } // configureLogger configures logger level and output func configureLogger(args options) { ls := getLogSettings() // command-line arguments can override config settings if args.verbose || config.Verbose { ls.Verbose = true } if args.logFile != "" { ls.File = args.logFile } else if config.File != "" { ls.File = config.File } // Handle default log settings overrides ls.Compress = config.Compress ls.LocalTime = config.LocalTime ls.MaxBackups = config.MaxBackups ls.MaxSize = config.MaxSize ls.MaxAge = config.MaxAge // log.SetLevel(log.INFO) - default if ls.Verbose { log.SetLevel(log.DEBUG) } // Make sure that we see the microseconds in logs, as networking stuff can // happen pretty quickly. log.SetFlags(log.LstdFlags | log.Lmicroseconds) if args.runningAsService && ls.File == "" && runtime.GOOS == "windows" { // When running as a Windows service, use eventlog by default if nothing // else is configured. Otherwise, we'll simply lose the log output. ls.File = configSyslog } // logs are written to stdout (default) if ls.File == "" { return } if ls.File == configSyslog { // Use syslog where it is possible and eventlog on Windows err := aghos.ConfigureSyslog(serviceName) if err != nil { log.Fatalf("cannot initialize syslog: %s", err) } } else { logFilePath := filepath.Join(Context.workDir, ls.File) if filepath.IsAbs(ls.File) { logFilePath = ls.File } _, err := os.OpenFile(logFilePath, os.O_WRONLY|os.O_CREATE|os.O_APPEND, 0o644) if err != nil { log.Fatalf("cannot create a log file: %s", err) } log.SetOutput(&lumberjack.Logger{ Filename: logFilePath, Compress: ls.Compress, // disabled by default LocalTime: ls.LocalTime, MaxBackups: ls.MaxBackups, MaxSize: ls.MaxSize, // megabytes MaxAge: ls.MaxAge, // days }) } } // cleanup stops and resets all the modules. func cleanup(ctx context.Context) { log.Info("stopping AdGuard Home") if Context.web != nil { Context.web.Close(ctx) Context.web = nil } if Context.auth != nil { Context.auth.Close() Context.auth = nil } err := stopDNSServer() if err != nil { log.Error("stopping dns server: %s", err) } if Context.dhcpServer != nil { err = Context.dhcpServer.Stop() if err != nil { log.Error("stopping dhcp server: %s", err) } } if Context.etcHosts != nil { // Currently Context.hostsWatcher is only used in Context.etcHosts and // needs closing only in case of the successful initialization of // Context.etcHosts. if err = Context.hostsWatcher.Close(); err != nil { log.Error("closing hosts watcher: %s", err) } if err = Context.etcHosts.Close(); err != nil { log.Error("closing hosts container: %s", err) } } if Context.tls != nil { Context.tls.Close() Context.tls = nil } } // This function is called before application exits func cleanupAlways() { if len(Context.pidFileName) != 0 { _ = os.Remove(Context.pidFileName) } log.Info("Stopped") } func exitWithError() { os.Exit(64) } // loadOptions reads command line arguments and initializes configuration func loadOptions() options { o, f, err := parse(os.Args[0], os.Args[1:]) if err != nil { log.Error(err.Error()) _ = printHelp(os.Args[0]) exitWithError() } else if f != nil { err = f() if err != nil { log.Error(err.Error()) exitWithError() } else { os.Exit(0) } } return o } // printWebAddrs prints addresses built from proto, addr, and an appropriate // port. At least one address is printed with the value of port. If the value // of betaPort is 0, the second address is not printed. Output example: // // Go to http://127.0.0.1:80 // Go to http://127.0.0.1:3000 (BETA) func printWebAddrs(proto, addr string, port, betaPort int) { const ( hostMsg = "Go to %s://%s" hostBetaMsg = hostMsg + " (BETA)" ) log.Printf(hostMsg, proto, netutil.JoinHostPort(addr, port)) if betaPort == 0 { return } log.Printf(hostBetaMsg, proto, netutil.JoinHostPort(addr, config.BetaBindPort)) } // printHTTPAddresses prints the IP addresses which user can use to access the // admin interface. proto is either schemeHTTP or schemeHTTPS. func printHTTPAddresses(proto string) { tlsConf := tlsConfigSettings{} if Context.tls != nil { Context.tls.WriteDiskConfig(&tlsConf) } port := config.BindPort if proto == schemeHTTPS { port = tlsConf.PortHTTPS } // TODO(e.burkov): Inspect and perhaps merge with the previous condition. if proto == schemeHTTPS && tlsConf.ServerName != "" { printWebAddrs(proto, tlsConf.ServerName, tlsConf.PortHTTPS, 0) return } bindhost := config.BindHost if !bindhost.IsUnspecified() { printWebAddrs(proto, bindhost.String(), port, config.BetaBindPort) return } ifaces, err := aghnet.GetValidNetInterfacesForWeb() if err != nil { log.Error("web: getting iface ips: %s", err) // That's weird, but we'll ignore it. // // TODO(e.burkov): Find out when it happens. printWebAddrs(proto, bindhost.String(), port, config.BetaBindPort) return } for _, iface := range ifaces { for _, addr := range iface.Addresses { printWebAddrs(proto, addr.String(), config.BindPort, config.BetaBindPort) } } } // ------------------- // first run / install // ------------------- func detectFirstRun() bool { configfile := Context.configFilename if !filepath.IsAbs(configfile) { configfile = filepath.Join(Context.workDir, Context.configFilename) } _, err := os.Stat(configfile) return errors.Is(err, os.ErrNotExist) } // Connect to a remote server resolving hostname using our own DNS server. // // TODO(e.burkov): This messy logic should be decomposed and clarified. func customDialContext(ctx context.Context, network, addr string) (conn net.Conn, err error) { log.Tracef("network:%v addr:%v", network, addr) host, port, err := net.SplitHostPort(addr) if err != nil { return nil, err } dialer := &net.Dialer{ Timeout: time.Minute * 5, } if net.ParseIP(host) != nil || config.DNS.Port == 0 { return dialer.DialContext(ctx, network, addr) } addrs, err := Context.dnsServer.Resolve(host) log.Debug("dnsServer.Resolve: %s: %v", host, addrs) if err != nil { return nil, err } if len(addrs) == 0 { return nil, fmt.Errorf("couldn't lookup host: %s", host) } var dialErrs []error for _, a := range addrs { addr = net.JoinHostPort(a.String(), port) conn, err = dialer.DialContext(ctx, network, addr) if err != nil { dialErrs = append(dialErrs, err) continue } return conn, err } return nil, errors.List(fmt.Sprintf("couldn't dial to %s", addr), dialErrs...) } func getHTTPProxy(_ *http.Request) (*url.URL, error) { if config.ProxyURL == "" { return nil, nil } return url.Parse(config.ProxyURL) } // jsonError is a generic JSON error response. // // TODO(a.garipov): Merge together with the implementations in .../dhcpd and // other packages after refactoring the web handler registering. type jsonError struct { // Message is the error message, an opaque string. Message string `json:"message"` }