package home import ( "encoding/json" "fmt" "net" "net/http" "strconv" "strings" "github.com/AdguardTeam/AdGuardHome/dnsforward" "github.com/AdguardTeam/dnsproxy/upstream" "github.com/AdguardTeam/golibs/log" "github.com/AdguardTeam/golibs/utils" "github.com/NYTimes/gziphandler" "github.com/miekg/dns" ) var protocols = []string{"tls://", "https://", "tcp://", "sdns://"} // ---------------- // helper functions // ---------------- func returnOK(w http.ResponseWriter) { _, err := fmt.Fprintf(w, "OK\n") if err != nil { httpError(w, http.StatusInternalServerError, "Couldn't write body: %s", err) } } func httpError(w http.ResponseWriter, code int, format string, args ...interface{}) { text := fmt.Sprintf(format, args...) log.Info(text) http.Error(w, text, code) } // --------------- // dns run control // --------------- func writeAllConfigsAndReloadDNS() error { err := writeAllConfigs() if err != nil { log.Error("Couldn't write all configs: %s", err) return err } return reconfigureDNSServer() } func httpUpdateConfigReloadDNSReturnOK(w http.ResponseWriter, r *http.Request) { err := writeAllConfigsAndReloadDNS() if err != nil { httpError(w, http.StatusInternalServerError, "Couldn't write config file: %s", err) return } returnOK(w) } func addDNSAddress(dnsAddresses *[]string, addr string) { if config.DNS.Port != 53 { addr = fmt.Sprintf("%s:%d", addr, config.DNS.Port) } *dnsAddresses = append(*dnsAddresses, addr) } // 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 := 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) } if config.TLS.Enabled && len(config.TLS.ServerName) != 0 { if config.TLS.PortHTTPS != 0 { addr := config.TLS.ServerName if config.TLS.PortHTTPS != 443 { addr = fmt.Sprintf("%s:%d", addr, config.TLS.PortHTTPS) } addr = fmt.Sprintf("https://%s/dns-query", addr) dnsAddresses = append(dnsAddresses, addr) } if config.TLS.PortDNSOverTLS != 0 { addr := fmt.Sprintf("tls://%s:%d", config.TLS.ServerName, config.TLS.PortDNSOverTLS) dnsAddresses = append(dnsAddresses, addr) } } return dnsAddresses } func handleStatus(w http.ResponseWriter, r *http.Request) { data := map[string]interface{}{ "dns_addresses": getDNSAddresses(), "http_port": config.BindPort, "dns_port": config.DNS.Port, "protection_enabled": config.DNS.ProtectionEnabled, "running": isRunning(), "bootstrap_dns": config.DNS.BootstrapDNS, "upstream_dns": config.DNS.UpstreamDNS, "all_servers": config.DNS.AllServers, "version": versionString, "language": config.Language, } jsonVal, err := json.Marshal(data) if err != nil { httpError(w, http.StatusInternalServerError, "Unable to marshal status json: %s", err) return } w.Header().Set("Content-Type", "application/json") _, err = w.Write(jsonVal) if err != nil { httpError(w, http.StatusInternalServerError, "Unable to write response json: %s", err) return } } func handleProtectionEnable(w http.ResponseWriter, r *http.Request) { config.DNS.ProtectionEnabled = true httpUpdateConfigReloadDNSReturnOK(w, r) } func handleProtectionDisable(w http.ResponseWriter, r *http.Request) { config.DNS.ProtectionEnabled = false httpUpdateConfigReloadDNSReturnOK(w, r) } // ----------------------- // upstreams configuration // ----------------------- // TODO this struct will become unnecessary after config file rework type upstreamConfig struct { Upstreams []string `json:"upstream_dns"` // Upstreams BootstrapDNS []string `json:"bootstrap_dns"` // Bootstrap DNS AllServers bool `json:"all_servers"` // --all-servers param for dnsproxy } func handleSetUpstreamConfig(w http.ResponseWriter, r *http.Request) { newconfig := upstreamConfig{} err := json.NewDecoder(r.Body).Decode(&newconfig) if err != nil { httpError(w, http.StatusBadRequest, "Failed to parse new upstreams config json: %s", err) return } err = validateUpstreams(newconfig.Upstreams) if err != nil { httpError(w, http.StatusBadRequest, "wrong upstreams specification: %s", err) return } config.DNS.UpstreamDNS = defaultDNS if len(newconfig.Upstreams) > 0 { config.DNS.UpstreamDNS = newconfig.Upstreams } // bootstrap servers are plain DNS only. for _, host := range newconfig.BootstrapDNS { if err := checkPlainDNS(host); err != nil { httpError(w, http.StatusBadRequest, "%s can not be used as bootstrap dns cause: %s", host, err) return } } config.DNS.BootstrapDNS = defaultBootstrap if len(newconfig.BootstrapDNS) > 0 { config.DNS.BootstrapDNS = newconfig.BootstrapDNS } config.DNS.AllServers = newconfig.AllServers httpUpdateConfigReloadDNSReturnOK(w, r) } // validateUpstreams validates each upstream and returns an error if any upstream is invalid or if there are no default upstreams specified func validateUpstreams(upstreams []string) error { var defaultUpstreamFound bool for _, u := range upstreams { d, err := validateUpstream(u) if err != nil { return err } // Check this flag until default upstream will not be found if !defaultUpstreamFound { defaultUpstreamFound = d } } // Return error if there are no default upstreams if !defaultUpstreamFound { return fmt.Errorf("no default upstreams specified") } return nil } func validateUpstream(u string) (bool, error) { // Check if user tries to specify upstream for domain u, defaultUpstream, err := separateUpstream(u) if err != nil { return defaultUpstream, err } // The special server address '#' means "use the default servers" if u == "#" && !defaultUpstream { return defaultUpstream, nil } // Check if the upstream has a valid protocol prefix for _, proto := range protocols { if strings.HasPrefix(u, proto) { return defaultUpstream, nil } } // Return error if the upstream contains '://' without any valid protocol if strings.Contains(u, "://") { return defaultUpstream, fmt.Errorf("wrong protocol") } // Check if upstream is valid plain DNS return defaultUpstream, checkPlainDNS(u) } // separateUpstream returns upstream without specified domains and a bool flag that indicates if no domains were specified // error will be returned if upstream per domain specification is invalid func separateUpstream(upstream string) (string, bool, error) { defaultUpstream := true if strings.HasPrefix(upstream, "[/") { defaultUpstream = false // split domains and upstream string domainsAndUpstream := strings.Split(strings.TrimPrefix(upstream, "[/"), "/]") if len(domainsAndUpstream) != 2 { return "", defaultUpstream, fmt.Errorf("wrong DNS upstream per domain specification: %s", upstream) } // split domains list and validate each one for _, host := range strings.Split(domainsAndUpstream[0], "/") { if host != "" { if err := utils.IsValidHostname(host); err != nil { return "", defaultUpstream, err } } } upstream = domainsAndUpstream[1] } return upstream, defaultUpstream, nil } // checkPlainDNS checks if host is plain DNS func checkPlainDNS(upstream string) error { // Check if host is ip without port if net.ParseIP(upstream) != nil { return nil } // Check if host is ip with port ip, port, err := net.SplitHostPort(upstream) if err != nil { return err } if net.ParseIP(ip) == nil { return fmt.Errorf("%s is not a valid IP", ip) } _, err = strconv.ParseInt(port, 0, 64) if err != nil { return fmt.Errorf("%s is not a valid port: %s", port, err) } return nil } func handleTestUpstreamDNS(w http.ResponseWriter, r *http.Request) { upstreamConfig := upstreamConfig{} err := json.NewDecoder(r.Body).Decode(&upstreamConfig) if err != nil { httpError(w, http.StatusBadRequest, "Failed to read request body: %s", err) return } if len(upstreamConfig.Upstreams) == 0 { httpError(w, http.StatusBadRequest, "No servers specified") return } result := map[string]string{} for _, host := range upstreamConfig.Upstreams { err = checkDNS(host, upstreamConfig.BootstrapDNS) if err != nil { log.Info("%v", err) result[host] = err.Error() } else { result[host] = "OK" } } jsonVal, err := json.Marshal(result) if err != nil { httpError(w, http.StatusInternalServerError, "Unable to marshal status json: %s", err) return } w.Header().Set("Content-Type", "application/json") _, err = w.Write(jsonVal) if err != nil { httpError(w, http.StatusInternalServerError, "Couldn't write body: %s", err) } } func checkDNS(input string, bootstrap []string) error { // separate upstream from domains list input, defaultUpstream, err := separateUpstream(input) if err != nil { return fmt.Errorf("wrong upstream format: %s", err) } // No need to check this entrance if input == "#" && !defaultUpstream { return nil } if _, err := validateUpstream(input); err != nil { return fmt.Errorf("wrong upstream format: %s", err) } if len(bootstrap) == 0 { bootstrap = defaultBootstrap } log.Debug("Checking if DNS %s works...", input) u, err := upstream.AddressToUpstream(input, upstream.Options{Bootstrap: bootstrap, Timeout: dnsforward.DefaultTimeout}) if err != nil { return fmt.Errorf("failed to choose upstream for %s: %s", input, err) } req := dns.Msg{} req.Id = dns.Id() req.RecursionDesired = true req.Question = []dns.Question{ {Name: "google-public-dns-a.google.com.", Qtype: dns.TypeA, Qclass: dns.ClassINET}, } reply, err := u.Exchange(&req) if err != nil { return fmt.Errorf("couldn't communicate with DNS server %s: %s", input, err) } if len(reply.Answer) != 1 { return fmt.Errorf("DNS server %s returned wrong answer", input) } if t, ok := reply.Answer[0].(*dns.A); ok { if !net.IPv4(8, 8, 8, 8).Equal(t.A) { return fmt.Errorf("DNS server %s returned wrong answer: %v", input, t.A) } } log.Debug("DNS %s works OK", input) return nil } type profileJSON struct { Name string `json:"name"` } func handleGetProfile(w http.ResponseWriter, r *http.Request) { pj := profileJSON{} u := config.auth.GetCurrentUser(r) pj.Name = u.Name data, err := json.Marshal(pj) if err != nil { httpError(w, http.StatusInternalServerError, "json.Marshal: %s", err) return } _, _ = w.Write(data) } // -------------- // DNS-over-HTTPS // -------------- func handleDOH(w http.ResponseWriter, r *http.Request) { if r.TLS == nil { httpError(w, http.StatusNotFound, "Not Found") return } if !isRunning() { httpError(w, http.StatusInternalServerError, "DNS server is not running") return } config.dnsServer.ServeHTTP(w, r) } // ------------------------ // registration of handlers // ------------------------ func registerControlHandlers() { httpRegister(http.MethodGet, "/control/status", handleStatus) httpRegister(http.MethodPost, "/control/enable_protection", handleProtectionEnable) httpRegister(http.MethodPost, "/control/disable_protection", handleProtectionDisable) httpRegister(http.MethodPost, "/control/set_upstreams_config", handleSetUpstreamConfig) httpRegister(http.MethodPost, "/control/test_upstream_dns", handleTestUpstreamDNS) httpRegister(http.MethodPost, "/control/i18n/change_language", handleI18nChangeLanguage) httpRegister(http.MethodGet, "/control/i18n/current_language", handleI18nCurrentLanguage) http.HandleFunc("/control/version.json", postInstall(optionalAuth(handleGetVersionJSON))) httpRegister(http.MethodPost, "/control/update", handleUpdate) httpRegister(http.MethodGet, "/control/dhcp/status", handleDHCPStatus) httpRegister(http.MethodGet, "/control/dhcp/interfaces", handleDHCPInterfaces) httpRegister(http.MethodPost, "/control/dhcp/set_config", handleDHCPSetConfig) httpRegister(http.MethodPost, "/control/dhcp/find_active_dhcp", handleDHCPFindActiveServer) httpRegister(http.MethodPost, "/control/dhcp/add_static_lease", handleDHCPAddStaticLease) httpRegister(http.MethodPost, "/control/dhcp/remove_static_lease", handleDHCPRemoveStaticLease) httpRegister(http.MethodGet, "/control/access/list", handleAccessList) httpRegister(http.MethodPost, "/control/access/set", handleAccessSet) httpRegister("GET", "/control/profile", handleGetProfile) RegisterFilteringHandlers() RegisterTLSHandlers() RegisterClientsHandlers() RegisterBlockedServicesHandlers() RegisterAuthHandlers() http.HandleFunc("/dns-query", postInstall(handleDOH)) } func httpRegister(method string, url string, handler func(http.ResponseWriter, *http.Request)) { http.Handle(url, postInstallHandler(optionalAuthHandler(gziphandler.GzipHandler(ensureHandler(method, handler))))) }