package home import ( "fmt" "net/http" "net/netip" "net/url" "runtime" "strings" "time" "github.com/AdguardTeam/AdGuardHome/internal/aghhttp" "github.com/AdguardTeam/AdGuardHome/internal/aghnet" "github.com/AdguardTeam/AdGuardHome/internal/dnsforward" "github.com/AdguardTeam/AdGuardHome/internal/version" "github.com/AdguardTeam/golibs/httphdr" "github.com/AdguardTeam/golibs/log" "github.com/AdguardTeam/golibs/mathutil" "github.com/AdguardTeam/golibs/netutil" "github.com/NYTimes/gziphandler" ) // appendDNSAddrs is a convenient helper for appending a formatted form of DNS // addresses to a slice of strings. func appendDNSAddrs(dst []string, addrs ...netip.Addr) (res []string) { for _, addr := range addrs { hostport := addr.String() if p := config.DNS.Port; p != defaultPortDNS { hostport = netutil.JoinHostPort(hostport, p) } dst = append(dst, hostport) } return dst } // appendDNSAddrsWithIfaces formats and appends all DNS addresses from src to // dst. It also adds the IP addresses of all network interfaces if src contains // an unspecified IP address. func appendDNSAddrsWithIfaces(dst []string, src []netip.Addr) (res []string, err error) { ifacesAdded := false for _, h := range src { if !h.IsUnspecified() { dst = appendDNSAddrs(dst, h) continue } else if ifacesAdded { continue } // Add addresses of all network interfaces for addresses like // "0.0.0.0" and "::". var ifaces []*aghnet.NetInterface ifaces, err = aghnet.GetValidNetInterfacesForWeb() if err != nil { return nil, fmt.Errorf("cannot get network interfaces: %w", err) } for _, iface := range ifaces { dst = appendDNSAddrs(dst, iface.Addresses...) } ifacesAdded = true } return dst, nil } // collectDNSAddresses returns the list of DNS addresses the server is listening // on, including the addresses on all interfaces in cases of unspecified IPs. func collectDNSAddresses() (addrs []string, err error) { if hosts := config.DNS.BindHosts; len(hosts) == 0 { addrs = appendDNSAddrs(addrs, netutil.IPv4Localhost()) } else { addrs, err = appendDNSAddrsWithIfaces(addrs, hosts) if err != nil { return nil, fmt.Errorf("collecting dns addresses: %w", err) } } de := getDNSEncryption() if de.https != "" { addrs = append(addrs, de.https) } if de.tls != "" { addrs = append(addrs, de.tls) } if de.quic != "" { addrs = append(addrs, de.quic) } return addrs, nil } // statusResponse is a response for /control/status endpoint. type statusResponse struct { Version string `json:"version"` Language string `json:"language"` DNSAddrs []string `json:"dns_addresses"` DNSPort uint16 `json:"dns_port"` HTTPPort uint16 `json:"http_port"` // ProtectionDisabledDuration is the duration of the protection pause in // milliseconds. ProtectionDisabledDuration int64 `json:"protection_disabled_duration"` ProtectionEnabled bool `json:"protection_enabled"` // TODO(e.burkov): Inspect if front-end doesn't requires this field as // openapi.yaml declares. IsDHCPAvailable bool `json:"dhcp_available"` IsRunning bool `json:"running"` } func handleStatus(w http.ResponseWriter, r *http.Request) { dnsAddrs, err := collectDNSAddresses() if err != nil { // Don't add a lot of formatting, since the error is already // wrapped by collectDNSAddresses. aghhttp.Error(r, w, http.StatusInternalServerError, "%s", err) return } var ( fltConf *dnsforward.Config protectionDisabledUntil *time.Time protectionEnabled bool ) if Context.dnsServer != nil { fltConf = &dnsforward.Config{} Context.dnsServer.WriteDiskConfig(fltConf) protectionEnabled, protectionDisabledUntil = Context.dnsServer.UpdatedProtectionStatus() } var resp statusResponse func() { config.RLock() defer config.RUnlock() var protectionDisabledDuration int64 if protectionDisabledUntil != nil { // Make sure that we don't send negative numbers to the frontend, // since enough time might have passed to make the difference less // than zero. protectionDisabledDuration = mathutil.Max( 0, time.Until(*protectionDisabledUntil).Milliseconds(), ) } resp = statusResponse{ Version: version.Version(), Language: config.Language, DNSAddrs: dnsAddrs, DNSPort: config.DNS.Port, HTTPPort: config.HTTPConfig.Address.Port(), ProtectionDisabledDuration: protectionDisabledDuration, ProtectionEnabled: protectionEnabled, IsRunning: isRunning(), } }() // IsDHCPAvailable field is now false by default for Windows. if runtime.GOOS != "windows" { resp.IsDHCPAvailable = Context.dhcpServer != nil } aghhttp.WriteJSONResponseOK(w, r, resp) } // ------------------------ // registration of handlers // ------------------------ func registerControlHandlers(web *webAPI) { Context.mux.HandleFunc( "/control/version.json", postInstall(optionalAuth(web.handleVersionJSON)), ) httpRegister(http.MethodPost, "/control/update", web.handleUpdate) httpRegister(http.MethodGet, "/control/status", handleStatus) httpRegister(http.MethodPost, "/control/i18n/change_language", handleI18nChangeLanguage) httpRegister(http.MethodGet, "/control/i18n/current_language", handleI18nCurrentLanguage) httpRegister(http.MethodGet, "/control/profile", handleGetProfile) httpRegister(http.MethodPut, "/control/profile/update", handlePutProfile) // No auth is necessary for DoH/DoT configurations Context.mux.HandleFunc("/apple/doh.mobileconfig", postInstall(handleMobileConfigDoH)) Context.mux.HandleFunc("/apple/dot.mobileconfig", postInstall(handleMobileConfigDoT)) RegisterAuthHandlers() } func httpRegister(method, url string, handler http.HandlerFunc) { if method == "" { // "/dns-query" handler doesn't need auth, gzip and isn't restricted by 1 HTTP method Context.mux.HandleFunc(url, postInstall(handler)) return } Context.mux.Handle(url, postInstallHandler(optionalAuthHandler(gziphandler.GzipHandler(ensureHandler(method, handler))))) } // ensure returns a wrapped handler that makes sure that the request has the // correct method as well as additional method and header checks. func ensure( method string, handler func(http.ResponseWriter, *http.Request), ) (wrapped func(http.ResponseWriter, *http.Request)) { return func(w http.ResponseWriter, r *http.Request) { start := time.Now() m, u := r.Method, r.URL log.Debug("started %s %s %s", m, r.Host, u) defer func() { log.Debug("finished %s %s %s in %s", m, r.Host, u, time.Since(start)) }() if m != method { aghhttp.Error(r, w, http.StatusMethodNotAllowed, "only method %s is allowed", method) return } if modifiesData(m) { if !ensureContentType(w, r) { return } Context.controlLock.Lock() defer Context.controlLock.Unlock() } handler(w, r) } } // modifiesData returns true if m is an HTTP method that can modify data. func modifiesData(m string) (ok bool) { return m == http.MethodPost || m == http.MethodPut || m == http.MethodDelete } // ensureContentType makes sure that the content type of a data-modifying // request is set correctly. If it is not, ensureContentType writes a response // to w, and ok is false. func ensureContentType(w http.ResponseWriter, r *http.Request) (ok bool) { const statusUnsup = http.StatusUnsupportedMediaType cType := r.Header.Get(httphdr.ContentType) if r.ContentLength == 0 { if cType == "" { return true } // Assume that browsers always send a content type when submitting HTML // forms and require no content type for requests with no body to make // sure that the request comes from JavaScript. aghhttp.Error(r, w, statusUnsup, "empty body with content-type %q not allowed", cType) return false } const wantCType = aghhttp.HdrValApplicationJSON if cType == wantCType { return true } aghhttp.Error(r, w, statusUnsup, "only content-type %s is allowed", wantCType) return false } func ensurePOST(handler func(http.ResponseWriter, *http.Request)) func(http.ResponseWriter, *http.Request) { return ensure(http.MethodPost, handler) } func ensureGET(handler func(http.ResponseWriter, *http.Request)) func(http.ResponseWriter, *http.Request) { return ensure(http.MethodGet, handler) } // Bridge between http.Handler object and Go function type httpHandler struct { handler func(http.ResponseWriter, *http.Request) } func (h *httpHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) { h.handler(w, r) } func ensureHandler(method string, handler func(http.ResponseWriter, *http.Request)) http.Handler { h := httpHandler{} h.handler = ensure(method, handler) return &h } // preInstall lets the handler run only if firstRun is true, no redirects func preInstall(handler func(http.ResponseWriter, *http.Request)) func(http.ResponseWriter, *http.Request) { return func(w http.ResponseWriter, r *http.Request) { if !Context.firstRun { // if it's not first run, don't let users access it (for example /install.html when configuration is done) http.Error(w, http.StatusText(http.StatusForbidden), http.StatusForbidden) return } handler(w, r) } } // preInstallStruct wraps preInstall into a struct that can be returned as an interface where necessary type preInstallHandlerStruct struct { handler http.Handler } func (p *preInstallHandlerStruct) ServeHTTP(w http.ResponseWriter, r *http.Request) { preInstall(p.handler.ServeHTTP)(w, r) } // preInstallHandler returns http.Handler interface for preInstall wrapper func preInstallHandler(handler http.Handler) http.Handler { return &preInstallHandlerStruct{handler} } // handleHTTPSRedirect redirects the request to HTTPS, if needed, and adds some // HTTPS-related headers. If proceed is true, the middleware must continue // handling the request. func handleHTTPSRedirect(w http.ResponseWriter, r *http.Request) (proceed bool) { web := Context.web if web.httpsServer.server == nil { return true } host, err := netutil.SplitHost(r.Host) if err != nil { aghhttp.Error(r, w, http.StatusBadRequest, "bad host: %s", err) return false } var ( forceHTTPS bool serveHTTP3 bool portHTTPS uint16 ) func() { config.RLock() defer config.RUnlock() serveHTTP3, portHTTPS = config.DNS.ServeHTTP3, config.TLS.PortHTTPS forceHTTPS = config.TLS.ForceHTTPS && config.TLS.Enabled && config.TLS.PortHTTPS != 0 }() respHdr := w.Header() // Let the browser know that server supports HTTP/3. // // See https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Alt-Svc. // // TODO(a.garipov): Consider adding a configurable max-age. Currently, the // default is 24 hours. if serveHTTP3 { altSvc := fmt.Sprintf(`h3=":%d"`, portHTTPS) respHdr.Set(httphdr.AltSvc, altSvc) } if forceHTTPS { if r.TLS == nil { u := httpsURL(r.URL, host, portHTTPS) http.Redirect(w, r, u.String(), http.StatusTemporaryRedirect) return false } // TODO(a.garipov): Consider adding a configurable max-age. Currently, // the default is 365 days. respHdr.Set(httphdr.StrictTransportSecurity, aghhttp.HdrValStrictTransportSecurity) } // Allow the frontend from the HTTP origin to send requests to the HTTPS // server. This can happen when the user has just set up HTTPS with // redirects. Prevent cache-related errors by setting the Vary header. // // See https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Access-Control-Allow-Origin. originURL := &url.URL{ Scheme: aghhttp.SchemeHTTP, Host: r.Host, } respHdr.Set(httphdr.AccessControlAllowOrigin, originURL.String()) respHdr.Set(httphdr.Vary, httphdr.Origin) return true } // httpsURL returns a copy of u for redirection to the HTTPS version, taking the // hostname and the HTTPS port into account. func httpsURL(u *url.URL, host string, portHTTPS uint16) (redirectURL *url.URL) { hostPort := host if portHTTPS != defaultPortHTTPS { hostPort = netutil.JoinHostPort(host, portHTTPS) } return &url.URL{ Scheme: aghhttp.SchemeHTTPS, Host: hostPort, Path: u.Path, RawQuery: u.RawQuery, } } // postInstall lets the handler to run only if firstRun is false. Otherwise, it // redirects to /install.html. It also enforces HTTPS if it is enabled and // configured and sets appropriate access control headers. func postInstall(handler func(http.ResponseWriter, *http.Request)) func(http.ResponseWriter, *http.Request) { return func(w http.ResponseWriter, r *http.Request) { path := r.URL.Path if Context.firstRun && !strings.HasPrefix(path, "/install.") && !strings.HasPrefix(path, "/assets/") { http.Redirect(w, r, "install.html", http.StatusFound) return } proceed := handleHTTPSRedirect(w, r) if proceed { handler(w, r) } } } type postInstallHandlerStruct struct { handler http.Handler } func (p *postInstallHandlerStruct) ServeHTTP(w http.ResponseWriter, r *http.Request) { postInstall(p.handler.ServeHTTP)(w, r) } func postInstallHandler(handler http.Handler) http.Handler { return &postInstallHandlerStruct{handler} }