package server import ( "bytes" "context" "embed" "encoding/json" "errors" firebase "firebase.google.com/go" "firebase.google.com/go/messaging" "fmt" "github.com/emersion/go-smtp" "google.golang.org/api/option" "heckel.io/ntfy/util" "html/template" "io" "log" "net" "net/http" "net/http/httptest" "regexp" "strconv" "strings" "sync" "time" ) // TODO add "max messages in a topic" limit // TODO implement "since=" // Server is the main server, providing the UI and API for ntfy type Server struct { config *Config httpServer *http.Server httpsServer *http.Server smtpServer *smtp.Server smtpBackend *smtpBackend topics map[string]*topic visitors map[string]*visitor firebase subscriber mailer mailer messages int64 cache cache closeChan chan bool mu sync.Mutex } // errHTTP is a generic HTTP error for any non-200 HTTP error type errHTTP struct { Code int `json:"code,omitempty"` HTTPCode int `json:"http"` Message string `json:"error"` Link string `json:"link,omitempty"` } func (e errHTTP) Error() string { return e.Message } func (e errHTTP) JSON() string { b, _ := json.Marshal(&e) return string(b) } type indexPage struct { Topic string CacheDuration time.Duration } type sinceTime time.Time func (t sinceTime) IsAll() bool { return t == sinceAllMessages } func (t sinceTime) IsNone() bool { return t == sinceNoMessages } func (t sinceTime) Time() time.Time { return time.Time(t) } var ( sinceAllMessages = sinceTime(time.Unix(0, 0)) sinceNoMessages = sinceTime(time.Unix(1, 0)) ) var ( topicRegex = regexp.MustCompile(`^[-_A-Za-z0-9]{1,64}$`) // No /! topicPathRegex = regexp.MustCompile(`^/[-_A-Za-z0-9]{1,64}$`) // Regex must match JS & Android app! jsonPathRegex = regexp.MustCompile(`^/[-_A-Za-z0-9]{1,64}(,[-_A-Za-z0-9]{1,64})*/json$`) ssePathRegex = regexp.MustCompile(`^/[-_A-Za-z0-9]{1,64}(,[-_A-Za-z0-9]{1,64})*/sse$`) rawPathRegex = regexp.MustCompile(`^/[-_A-Za-z0-9]{1,64}(,[-_A-Za-z0-9]{1,64})*/raw$`) publishPathRegex = regexp.MustCompile(`^/[-_A-Za-z0-9]{1,64}(,[-_A-Za-z0-9]{1,64})*/(publish|send|trigger)$`) staticRegex = regexp.MustCompile(`^/static/.+`) docsRegex = regexp.MustCompile(`^/docs(|/.*)$`) disallowedTopics = []string{"docs", "static"} templateFnMap = template.FuncMap{ "durationToHuman": util.DurationToHuman, } //go:embed "index.gohtml" indexSource string indexTemplate = template.Must(template.New("index").Funcs(templateFnMap).Parse(indexSource)) //go:embed "example.html" exampleSource string //go:embed static webStaticFs embed.FS webStaticFsCached = &util.CachingEmbedFS{ModTime: time.Now(), FS: webStaticFs} //go:embed docs docsStaticFs embed.FS docsStaticCached = &util.CachingEmbedFS{ModTime: time.Now(), FS: docsStaticFs} errHTTPNotFound = &errHTTP{40401, http.StatusNotFound, "page not found", ""} errHTTPTooManyRequestsLimitRequests = &errHTTP{42901, http.StatusTooManyRequests, "limit reached: too many requests, please be nice", "https://ntfy.sh/docs/publish/#limitations"} errHTTPTooManyRequestsLimitEmails = &errHTTP{42902, http.StatusTooManyRequests, "limit reached: too many emails, please be nice", "https://ntfy.sh/docs/publish/#limitations"} errHTTPTooManyRequestsLimitSubscriptions = &errHTTP{42903, http.StatusTooManyRequests, "limit reached: too many active subscriptions, please be nice", "https://ntfy.sh/docs/publish/#limitations"} errHTTPTooManyRequestsLimitGlobalTopics = &errHTTP{42904, http.StatusTooManyRequests, "limit reached: the total number of topics on the server has been reached, please contact the admin", "https://ntfy.sh/docs/publish/#limitations"} errHTTPBadRequestEmailDisabled = &errHTTP{40001, http.StatusBadRequest, "e-mail notifications are not enabled", "https://ntfy.sh/docs/config/#e-mail-notifications"} errHTTPBadRequestDelayNoCache = &errHTTP{40002, http.StatusBadRequest, "cannot disable cache for delayed message", ""} errHTTPBadRequestDelayNoEmail = &errHTTP{40003, http.StatusBadRequest, "delayed e-mail notifications are not supported", ""} errHTTPBadRequestDelayCannotParse = &errHTTP{40004, http.StatusBadRequest, "invalid delay parameter: unable to parse delay", "https://ntfy.sh/docs/publish/#scheduled-delivery"} errHTTPBadRequestDelayTooSmall = &errHTTP{40005, http.StatusBadRequest, "invalid delay parameter: too small, please refer to the docs", "https://ntfy.sh/docs/publish/#scheduled-delivery"} errHTTPBadRequestDelayTooLarge = &errHTTP{40006, http.StatusBadRequest, "invalid delay parameter: too large, please refer to the docs", "https://ntfy.sh/docs/publish/#scheduled-delivery"} errHTTPBadRequestPriorityInvalid = &errHTTP{40007, http.StatusBadRequest, "invalid priority parameter", "https://ntfy.sh/docs/publish/#message-priority"} errHTTPBadRequestSinceInvalid = &errHTTP{40008, http.StatusBadRequest, "invalid since parameter", "https://ntfy.sh/docs/subscribe/api/#fetch-cached-messages"} errHTTPBadRequestTopicInvalid = &errHTTP{40009, http.StatusBadRequest, "invalid topic: path invalid", ""} errHTTPBadRequestTopicDisallowed = &errHTTP{40010, http.StatusBadRequest, "invalid topic: topic name is disallowed", ""} errHTTPInternalError = &errHTTP{50001, http.StatusInternalServerError, "internal server error", ""} ) const ( firebaseControlTopic = "~control" // See Android if changed emptyMessageBody = "triggered" ) // New instantiates a new Server. It creates the cache and adds a Firebase // subscriber (if configured). func New(conf *Config) (*Server, error) { var firebaseSubscriber subscriber if conf.FirebaseKeyFile != "" { var err error firebaseSubscriber, err = createFirebaseSubscriber(conf) if err != nil { return nil, err } } var mailer mailer if conf.SMTPSenderAddr != "" { mailer = &smtpSender{config: conf} } cache, err := createCache(conf) if err != nil { return nil, err } topics, err := cache.Topics() if err != nil { return nil, err } return &Server{ config: conf, cache: cache, firebase: firebaseSubscriber, mailer: mailer, topics: topics, visitors: make(map[string]*visitor), }, nil } func createCache(conf *Config) (cache, error) { if conf.CacheDuration == 0 { return newNopCache(), nil } else if conf.CacheFile != "" { return newSqliteCache(conf.CacheFile) } return newMemCache(), nil } func createFirebaseSubscriber(conf *Config) (subscriber, error) { fb, err := firebase.NewApp(context.Background(), nil, option.WithCredentialsFile(conf.FirebaseKeyFile)) if err != nil { return nil, err } msg, err := fb.Messaging(context.Background()) if err != nil { return nil, err } return func(m *message) error { var data map[string]string // Matches https://ntfy.sh/docs/subscribe/api/#json-message-format switch m.Event { case keepaliveEvent, openEvent: data = map[string]string{ "id": m.ID, "time": fmt.Sprintf("%d", m.Time), "event": m.Event, "topic": m.Topic, } case messageEvent: data = map[string]string{ "id": m.ID, "time": fmt.Sprintf("%d", m.Time), "event": m.Event, "topic": m.Topic, "priority": fmt.Sprintf("%d", m.Priority), "tags": strings.Join(m.Tags, ","), "title": m.Title, "message": m.Message, } } _, err := msg.Send(context.Background(), &messaging.Message{ Topic: m.Topic, Data: data, }) return err }, nil } // Run executes the main server. It listens on HTTP (+ HTTPS, if configured), and starts // a manager go routine to print stats and prune messages. func (s *Server) Run() error { listenStr := fmt.Sprintf("%s/http", s.config.ListenHTTP) if s.config.ListenHTTPS != "" { listenStr += fmt.Sprintf(" %s/https", s.config.ListenHTTPS) } if s.config.SMTPServerListen != "" { listenStr += fmt.Sprintf(" %s/smtp", s.config.SMTPServerListen) } log.Printf("Listening on %s", listenStr) mux := http.NewServeMux() mux.HandleFunc("/", s.handle) errChan := make(chan error) s.mu.Lock() s.closeChan = make(chan bool) s.httpServer = &http.Server{Addr: s.config.ListenHTTP, Handler: mux} go func() { errChan <- s.httpServer.ListenAndServe() }() if s.config.ListenHTTPS != "" { s.httpsServer = &http.Server{Addr: s.config.ListenHTTP, Handler: mux} go func() { errChan <- s.httpsServer.ListenAndServeTLS(s.config.CertFile, s.config.KeyFile) }() } if s.config.SMTPServerListen != "" { go func() { errChan <- s.runSMTPServer() }() } s.mu.Unlock() go s.runManager() go s.runAtSender() go s.runFirebaseKeepliver() return <-errChan } // Stop stops HTTP (+HTTPS) server and all managers func (s *Server) Stop() { s.mu.Lock() defer s.mu.Unlock() if s.httpServer != nil { s.httpServer.Close() } if s.httpsServer != nil { s.httpsServer.Close() } if s.smtpServer != nil { s.smtpServer.Close() } close(s.closeChan) } func (s *Server) handle(w http.ResponseWriter, r *http.Request) { if err := s.handleInternal(w, r); err != nil { var e *errHTTP var ok bool if e, ok = err.(*errHTTP); !ok { e = errHTTPInternalError } log.Printf("[%s] %s - %d - %s", r.RemoteAddr, r.Method, e.HTTPCode, err.Error()) w.Header().Set("Content-Type", "application/json") w.Header().Set("Access-Control-Allow-Origin", "*") // CORS, allow cross-origin requests w.WriteHeader(e.HTTPCode) io.WriteString(w, e.JSON()+"\n") } } func (s *Server) handleInternal(w http.ResponseWriter, r *http.Request) error { if r.Method == http.MethodGet && r.URL.Path == "/" { return s.handleHome(w, r) } else if r.Method == http.MethodGet && r.URL.Path == "/example.html" { return s.handleExample(w, r) } else if r.Method == http.MethodHead && r.URL.Path == "/" { return s.handleEmpty(w, r) } else if r.Method == http.MethodGet && staticRegex.MatchString(r.URL.Path) { return s.handleStatic(w, r) } else if r.Method == http.MethodGet && docsRegex.MatchString(r.URL.Path) { return s.handleDocs(w, r) } else if r.Method == http.MethodOptions { return s.handleOptions(w, r) } else if r.Method == http.MethodGet && topicPathRegex.MatchString(r.URL.Path) { return s.handleTopic(w, r) } else if (r.Method == http.MethodPut || r.Method == http.MethodPost) && topicPathRegex.MatchString(r.URL.Path) { return s.withRateLimit(w, r, s.handlePublish) } else if r.Method == http.MethodGet && publishPathRegex.MatchString(r.URL.Path) { return s.withRateLimit(w, r, s.handlePublish) } else if r.Method == http.MethodGet && jsonPathRegex.MatchString(r.URL.Path) { return s.withRateLimit(w, r, s.handleSubscribeJSON) } else if r.Method == http.MethodGet && ssePathRegex.MatchString(r.URL.Path) { return s.withRateLimit(w, r, s.handleSubscribeSSE) } else if r.Method == http.MethodGet && rawPathRegex.MatchString(r.URL.Path) { return s.withRateLimit(w, r, s.handleSubscribeRaw) } return errHTTPNotFound } func (s *Server) handleHome(w http.ResponseWriter, r *http.Request) error { return indexTemplate.Execute(w, &indexPage{ Topic: r.URL.Path[1:], CacheDuration: s.config.CacheDuration, }) } func (s *Server) handleTopic(w http.ResponseWriter, r *http.Request) error { unifiedpush := readParam(r, "x-unifiedpush", "unifiedpush", "up") == "1" // see PUT/POST too! if unifiedpush { w.Header().Set("Content-Type", "application/json") w.Header().Set("Access-Control-Allow-Origin", "*") // CORS, allow cross-origin requests _, err := io.WriteString(w, `{"unifiedpush":{"version":1}}`+"\n") return err } return s.handleHome(w, r) } func (s *Server) handleEmpty(_ http.ResponseWriter, _ *http.Request) error { return nil } func (s *Server) handleExample(w http.ResponseWriter, _ *http.Request) error { _, err := io.WriteString(w, exampleSource) return err } func (s *Server) handleStatic(w http.ResponseWriter, r *http.Request) error { http.FileServer(http.FS(webStaticFsCached)).ServeHTTP(w, r) return nil } func (s *Server) handleDocs(w http.ResponseWriter, r *http.Request) error { http.FileServer(http.FS(docsStaticCached)).ServeHTTP(w, r) return nil } func (s *Server) handlePublish(w http.ResponseWriter, r *http.Request, v *visitor) error { t, err := s.topicFromPath(r.URL.Path) if err != nil { return err } reader := io.LimitReader(r.Body, int64(s.config.MessageLimit)) b, err := io.ReadAll(reader) if err != nil { return err } m := newDefaultMessage(t.ID, strings.TrimSpace(string(b))) cache, firebase, email, err := s.parsePublishParams(r, m) if err != nil { return err } if email != "" { if err := v.EmailAllowed(); err != nil { return errHTTPTooManyRequestsLimitEmails } } if s.mailer == nil && email != "" { return errHTTPBadRequestEmailDisabled } if m.Message == "" { m.Message = emptyMessageBody } delayed := m.Time > time.Now().Unix() if !delayed { if err := t.Publish(m); err != nil { return err } } if s.firebase != nil && firebase && !delayed { go func() { if err := s.firebase(m); err != nil { log.Printf("Unable to publish to Firebase: %v", err.Error()) } }() } if s.mailer != nil && email != "" && !delayed { go func() { if err := s.mailer.Send(v.ip, email, m); err != nil { log.Printf("Unable to send email: %v", err.Error()) } }() } if cache { if err := s.cache.AddMessage(m); err != nil { return err } } w.Header().Set("Content-Type", "application/json") w.Header().Set("Access-Control-Allow-Origin", "*") // CORS, allow cross-origin requests if err := json.NewEncoder(w).Encode(m); err != nil { return err } s.inc(&s.messages) return nil } func (s *Server) parsePublishParams(r *http.Request, m *message) (cache bool, firebase bool, email string, err error) { cache = readParam(r, "x-cache", "cache") != "no" firebase = readParam(r, "x-firebase", "firebase") != "no" email = readParam(r, "x-email", "x-e-mail", "email", "e-mail", "mail", "e") m.Title = readParam(r, "x-title", "title", "t") messageStr := readParam(r, "x-message", "message", "m") if messageStr != "" { m.Message = messageStr } m.Priority, err = util.ParsePriority(readParam(r, "x-priority", "priority", "prio", "p")) if err != nil { return false, false, "", errHTTPBadRequestPriorityInvalid } tagsStr := readParam(r, "x-tags", "tags", "tag", "ta") if tagsStr != "" { m.Tags = make([]string, 0) for _, s := range util.SplitNoEmpty(tagsStr, ",") { m.Tags = append(m.Tags, strings.TrimSpace(s)) } } delayStr := readParam(r, "x-delay", "delay", "x-at", "at", "x-in", "in") if delayStr != "" { if !cache { return false, false, "", errHTTPBadRequestDelayNoCache } if email != "" { return false, false, "", errHTTPBadRequestDelayNoEmail // we cannot store the email address (yet) } delay, err := util.ParseFutureTime(delayStr, time.Now()) if err != nil { return false, false, "", errHTTPBadRequestDelayCannotParse } else if delay.Unix() < time.Now().Add(s.config.MinDelay).Unix() { return false, false, "", errHTTPBadRequestDelayTooSmall } else if delay.Unix() > time.Now().Add(s.config.MaxDelay).Unix() { return false, false, "", errHTTPBadRequestDelayTooLarge } m.Time = delay.Unix() } unifiedpush := readParam(r, "x-unifiedpush", "unifiedpush", "up") == "1" // see GET too! if unifiedpush { firebase = false } return cache, firebase, email, nil } func readParam(r *http.Request, names ...string) string { for _, name := range names { value := r.Header.Get(name) if value != "" { return strings.TrimSpace(value) } } for _, name := range names { value := r.URL.Query().Get(strings.ToLower(name)) if value != "" { return strings.TrimSpace(value) } } return "" } func (s *Server) handleSubscribeJSON(w http.ResponseWriter, r *http.Request, v *visitor) error { encoder := func(msg *message) (string, error) { var buf bytes.Buffer if err := json.NewEncoder(&buf).Encode(&msg); err != nil { return "", err } return buf.String(), nil } return s.handleSubscribe(w, r, v, "json", "application/x-ndjson", encoder) } func (s *Server) handleSubscribeSSE(w http.ResponseWriter, r *http.Request, v *visitor) error { encoder := func(msg *message) (string, error) { var buf bytes.Buffer if err := json.NewEncoder(&buf).Encode(&msg); err != nil { return "", err } if msg.Event != messageEvent { return fmt.Sprintf("event: %s\ndata: %s\n", msg.Event, buf.String()), nil // Browser's .onmessage() does not fire on this! } return fmt.Sprintf("data: %s\n", buf.String()), nil } return s.handleSubscribe(w, r, v, "sse", "text/event-stream", encoder) } func (s *Server) handleSubscribeRaw(w http.ResponseWriter, r *http.Request, v *visitor) error { encoder := func(msg *message) (string, error) { if msg.Event == messageEvent { // only handle default events return strings.ReplaceAll(msg.Message, "\n", " ") + "\n", nil } return "\n", nil // "keepalive" and "open" events just send an empty line } return s.handleSubscribe(w, r, v, "raw", "text/plain", encoder) } func (s *Server) handleSubscribe(w http.ResponseWriter, r *http.Request, v *visitor, format string, contentType string, encoder messageEncoder) error { if err := v.SubscriptionAllowed(); err != nil { return errHTTPTooManyRequestsLimitSubscriptions } defer v.RemoveSubscription() topicsStr := strings.TrimSuffix(r.URL.Path[1:], "/"+format) // Hack topicIDs := util.SplitNoEmpty(topicsStr, ",") topics, err := s.topicsFromIDs(topicIDs...) if err != nil { return err } poll := readParam(r, "x-poll", "poll", "po") == "1" scheduled := readParam(r, "x-scheduled", "scheduled", "sched") == "1" since, err := parseSince(r, poll) if err != nil { return err } messageFilter, titleFilter, priorityFilter, tagsFilter, err := parseQueryFilters(r) if err != nil { return err } var wlock sync.Mutex sub := func(msg *message) error { if !passesQueryFilter(msg, messageFilter, titleFilter, priorityFilter, tagsFilter) { return nil } m, err := encoder(msg) if err != nil { return err } wlock.Lock() defer wlock.Unlock() if _, err := w.Write([]byte(m)); err != nil { return err } if fl, ok := w.(http.Flusher); ok { fl.Flush() } return nil } w.Header().Set("Access-Control-Allow-Origin", "*") // CORS, allow cross-origin requests w.Header().Set("Content-Type", contentType+"; charset=utf-8") // Android/Volley client needs charset! if poll { return s.sendOldMessages(topics, since, scheduled, sub) } subscriberIDs := make([]int, 0) for _, t := range topics { subscriberIDs = append(subscriberIDs, t.Subscribe(sub)) } defer func() { for i, subscriberID := range subscriberIDs { topics[i].Unsubscribe(subscriberID) // Order! } }() if err := sub(newOpenMessage(topicsStr)); err != nil { // Send out open message return err } if err := s.sendOldMessages(topics, since, scheduled, sub); err != nil { return err } for { select { case <-r.Context().Done(): return nil case <-time.After(s.config.KeepaliveInterval): v.Keepalive() if err := sub(newKeepaliveMessage(topicsStr)); err != nil { // Send keepalive message return err } } } } func parseQueryFilters(r *http.Request) (messageFilter string, titleFilter string, priorityFilter []int, tagsFilter []string, err error) { messageFilter = readParam(r, "x-message", "message", "m") titleFilter = readParam(r, "x-title", "title", "t") tagsFilter = util.SplitNoEmpty(readParam(r, "x-tags", "tags", "tag", "ta"), ",") priorityFilter = make([]int, 0) for _, p := range util.SplitNoEmpty(readParam(r, "x-priority", "priority", "prio", "p"), ",") { priority, err := util.ParsePriority(p) if err != nil { return "", "", nil, nil, err } priorityFilter = append(priorityFilter, priority) } return } func passesQueryFilter(msg *message, messageFilter string, titleFilter string, priorityFilter []int, tagsFilter []string) bool { if msg.Event != messageEvent { return true // filters only apply to messages } if messageFilter != "" && msg.Message != messageFilter { return false } if titleFilter != "" && msg.Title != titleFilter { return false } messagePriority := msg.Priority if messagePriority == 0 { messagePriority = 3 // For query filters, default priority (3) is the same as "not set" (0) } if len(priorityFilter) > 0 && !util.InIntList(priorityFilter, messagePriority) { return false } if len(tagsFilter) > 0 && !util.InStringListAll(msg.Tags, tagsFilter) { return false } return true } func (s *Server) sendOldMessages(topics []*topic, since sinceTime, scheduled bool, sub subscriber) error { if since.IsNone() { return nil } for _, t := range topics { messages, err := s.cache.Messages(t.ID, since, scheduled) if err != nil { return err } for _, m := range messages { if err := sub(m); err != nil { return err } } } return nil } // parseSince returns a timestamp identifying the time span from which cached messages should be received. // // Values in the "since=..." parameter can be either a unix timestamp or a duration (e.g. 12h), or // "all" for all messages. func parseSince(r *http.Request, poll bool) (sinceTime, error) { since := readParam(r, "x-since", "since", "si") if since == "" { if poll { return sinceAllMessages, nil } return sinceNoMessages, nil } if since == "all" { return sinceAllMessages, nil } else if s, err := strconv.ParseInt(since, 10, 64); err == nil { return sinceTime(time.Unix(s, 0)), nil } else if d, err := time.ParseDuration(since); err == nil { return sinceTime(time.Now().Add(-1 * d)), nil } return sinceNoMessages, errHTTPBadRequestSinceInvalid } func (s *Server) handleOptions(w http.ResponseWriter, _ *http.Request) error { w.Header().Set("Access-Control-Allow-Origin", "*") // CORS, allow cross-origin requests w.Header().Set("Access-Control-Allow-Methods", "GET, PUT, POST") return nil } func (s *Server) topicFromPath(path string) (*topic, error) { parts := strings.Split(path, "/") if len(parts) < 2 { return nil, errHTTPBadRequestTopicInvalid } topics, err := s.topicsFromIDs(parts[1]) if err != nil { return nil, err } return topics[0], nil } func (s *Server) topicsFromIDs(ids ...string) ([]*topic, error) { s.mu.Lock() defer s.mu.Unlock() topics := make([]*topic, 0) for _, id := range ids { if util.InStringList(disallowedTopics, id) { return nil, errHTTPBadRequestTopicDisallowed } if _, ok := s.topics[id]; !ok { if len(s.topics) >= s.config.GlobalTopicLimit { return nil, errHTTPTooManyRequestsLimitGlobalTopics } s.topics[id] = newTopic(id) } topics = append(topics, s.topics[id]) } return topics, nil } func (s *Server) updateStatsAndPrune() { s.mu.Lock() defer s.mu.Unlock() // Expire visitors from rate visitors map for ip, v := range s.visitors { if v.Stale() { delete(s.visitors, ip) } } // Prune message cache olderThan := time.Now().Add(-1 * s.config.CacheDuration) if err := s.cache.Prune(olderThan); err != nil { log.Printf("error pruning cache: %s", err.Error()) } // Prune old topics, remove subscriptions without subscribers var subscribers, messages int for _, t := range s.topics { subs := t.Subscribers() msgs, err := s.cache.MessageCount(t.ID) if err != nil { log.Printf("cannot get stats for topic %s: %s", t.ID, err.Error()) continue } if msgs == 0 && subs == 0 { delete(s.topics, t.ID) continue } subscribers += subs messages += msgs } // Mail mailSuccess, mailFailure := s.smtpBackend.Counts() // Print stats log.Printf("Stats: %d message(s) published, %d in cache, %d successful mails, %d failed, %d topic(s) active, %d subscriber(s), %d visitor(s)", s.messages, messages, mailSuccess, mailFailure, len(s.topics), subscribers, len(s.visitors)) } func (s *Server) runSMTPServer() error { sub := func(m *message) error { url := fmt.Sprintf("%s/%s", s.config.BaseURL, m.Topic) req, err := http.NewRequest("PUT", url, strings.NewReader(m.Message)) if err != nil { return err } if m.Title != "" { req.Header.Set("Title", m.Title) } rr := httptest.NewRecorder() s.handle(rr, req) if rr.Code != http.StatusOK { return errors.New("error: " + rr.Body.String()) } return nil } s.smtpBackend = newMailBackend(s.config, sub) s.smtpServer = smtp.NewServer(s.smtpBackend) s.smtpServer.Addr = s.config.SMTPServerListen s.smtpServer.Domain = s.config.SMTPServerDomain s.smtpServer.ReadTimeout = 10 * time.Second s.smtpServer.WriteTimeout = 10 * time.Second s.smtpServer.MaxMessageBytes = 2 * s.config.MessageLimit s.smtpServer.MaxRecipients = 1 s.smtpServer.AllowInsecureAuth = true return s.smtpServer.ListenAndServe() } func (s *Server) runManager() { for { select { case <-time.After(s.config.ManagerInterval): s.updateStatsAndPrune() case <-s.closeChan: return } } } func (s *Server) runAtSender() { for { select { case <-time.After(s.config.AtSenderInterval): if err := s.sendDelayedMessages(); err != nil { log.Printf("error sending scheduled messages: %s", err.Error()) } case <-s.closeChan: return } } } func (s *Server) runFirebaseKeepliver() { if s.firebase == nil { return } for { select { case <-time.After(s.config.FirebaseKeepaliveInterval): if err := s.firebase(newKeepaliveMessage(firebaseControlTopic)); err != nil { log.Printf("error sending Firebase keepalive message: %s", err.Error()) } case <-s.closeChan: return } } } func (s *Server) sendDelayedMessages() error { s.mu.Lock() defer s.mu.Unlock() messages, err := s.cache.MessagesDue() if err != nil { return err } for _, m := range messages { t, ok := s.topics[m.Topic] // If no subscribers, just mark message as published if ok { if err := t.Publish(m); err != nil { log.Printf("unable to publish message %s to topic %s: %v", m.ID, m.Topic, err.Error()) } if s.firebase != nil { if err := s.firebase(m); err != nil { log.Printf("unable to publish to Firebase: %v", err.Error()) } } // TODO delayed email sending } if err := s.cache.MarkPublished(m); err != nil { return err } } return nil } func (s *Server) withRateLimit(w http.ResponseWriter, r *http.Request, handler func(w http.ResponseWriter, r *http.Request, v *visitor) error) error { v := s.visitor(r) if err := v.RequestAllowed(); err != nil { return errHTTPTooManyRequestsLimitRequests } return handler(w, r, v) } // visitor creates or retrieves a rate.Limiter for the given visitor. // This function was taken from https://www.alexedwards.net/blog/how-to-rate-limit-http-requests (MIT). func (s *Server) visitor(r *http.Request) *visitor { s.mu.Lock() defer s.mu.Unlock() remoteAddr := r.RemoteAddr ip, _, err := net.SplitHostPort(remoteAddr) if err != nil { ip = remoteAddr // This should not happen in real life; only in tests. } if s.config.BehindProxy && r.Header.Get("X-Forwarded-For") != "" { ip = r.Header.Get("X-Forwarded-For") } v, exists := s.visitors[ip] if !exists { s.visitors[ip] = newVisitor(s.config, ip) return s.visitors[ip] } v.Keepalive() return v } func (s *Server) inc(counter *int64) { s.mu.Lock() defer s.mu.Unlock() *counter++ }