package server import ( "bytes" "context" "embed" // required for go:embed "encoding/json" firebase "firebase.google.com/go" "firebase.google.com/go/messaging" "fmt" "google.golang.org/api/option" "heckel.io/ntfy/util" "html/template" "io" "log" "net" "net/http" "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 topics map[string]*topic visitors map[string]*visitor firebase subscriber messages int64 cache cache mu sync.Mutex } // errHTTP is a generic HTTP error for any non-200 HTTP error type errHTTP struct { Code int Status string } func (e errHTTP) Error() string { return fmt.Sprintf("http: %s", e.Status) } 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}$`) // Regex must match JS & Android app! jsonRegex = regexp.MustCompile(`^/[-_A-Za-z0-9]{1,64}(,[-_A-Za-z0-9]{1,64})*/json$`) sseRegex = regexp.MustCompile(`^/[-_A-Za-z0-9]{1,64}(,[-_A-Za-z0-9]{1,64})*/sse$`) rawRegex = regexp.MustCompile(`^/[-_A-Za-z0-9]{1,64}(,[-_A-Za-z0-9]{1,64})*/raw$`) sendRegex = 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} errHTTPBadRequest = &errHTTP{http.StatusBadRequest, http.StatusText(http.StatusBadRequest)} errHTTPNotFound = &errHTTP{http.StatusNotFound, http.StatusText(http.StatusNotFound)} errHTTPTooManyRequests = &errHTTP{http.StatusTooManyRequests, http.StatusText(http.StatusTooManyRequests)} ) const ( firebaseControlTopic = "~control" // See Android if changed ) // 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 } } 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, 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 { go s.runManager() go s.runAtSender() go s.runFirebaseKeepliver() listenStr := fmt.Sprintf("%s/http", s.config.ListenHTTP) if s.config.ListenHTTPS != "" { listenStr += fmt.Sprintf(" %s/https", s.config.ListenHTTPS) } log.Printf("Listening on %s", listenStr) http.HandleFunc("/", s.handle) errChan := make(chan error) go func() { errChan <- http.ListenAndServe(s.config.ListenHTTP, nil) }() if s.config.ListenHTTPS != "" { go func() { errChan <- http.ListenAndServeTLS(s.config.ListenHTTPS, s.config.CertFile, s.config.KeyFile, nil) }() } return <-errChan } func (s *Server) handle(w http.ResponseWriter, r *http.Request) { if err := s.handleInternal(w, r); err != nil { if e, ok := err.(*errHTTP); ok { s.fail(w, r, e.Code, e) } else { s.fail(w, r, http.StatusInternalServerError, err) } } } 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 && topicRegex.MatchString(r.URL.Path) { return s.handleHome(w, r) } else if (r.Method == http.MethodPut || r.Method == http.MethodPost) && topicRegex.MatchString(r.URL.Path) { return s.withRateLimit(w, r, s.handlePublish) } else if r.Method == http.MethodGet && sendRegex.MatchString(r.URL.Path) { return s.withRateLimit(w, r, s.handlePublish) } else if r.Method == http.MethodGet && jsonRegex.MatchString(r.URL.Path) { return s.withRateLimit(w, r, s.handleSubscribeJSON) } else if r.Method == http.MethodGet && sseRegex.MatchString(r.URL.Path) { return s.withRateLimit(w, r, s.handleSubscribeSSE) } else if r.Method == http.MethodGet && rawRegex.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) 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, _ *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, err := s.parseParams(r, m) if err != nil { return err } if m.Message == "" { m.Message = "triggered" } 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 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) parseParams(r *http.Request, m *message) (cache bool, firebase bool, err error) { cache = readParam(r, "x-cache", "cache") != "no" firebase = readParam(r, "x-firebase", "firebase") != "no" 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, errHTTPBadRequest } 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, errHTTPBadRequest } delay, err := util.ParseFutureTime(delayStr, time.Now()) if err != nil { return false, false, errHTTPBadRequest } else if delay.Unix() < time.Now().Add(s.config.MinDelay).Unix() { return false, false, errHTTPBadRequest } else if delay.Unix() > time.Now().Add(s.config.MaxDelay).Unix() { return false, false, errHTTPBadRequest } m.Time = delay.Unix() } return cache, firebase, 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.AddSubscription(); err != nil { return errHTTPTooManyRequests } 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, err = util.ParsePriority(readParam(r, "x-priority", "priority", "prio", "p")) return // may be err! } 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 priorityFilter > 0 && messagePriority != priorityFilter { 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, errHTTPBadRequest } 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, errHTTPBadRequest } 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, errHTTPBadRequest } if _, ok := s.topics[id]; !ok { if len(s.topics) >= s.config.GlobalTopicLimit { return nil, errHTTPTooManyRequests } 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 } // Print stats log.Printf("Stats: %d message(s) published, %d topic(s) active, %d subscriber(s), %d message(s) buffered, %d visitor(s)", s.messages, len(s.topics), subscribers, messages, len(s.visitors)) } func (s *Server) runManager() { func() { ticker := time.NewTicker(s.config.ManagerInterval) for { <-ticker.C s.updateStatsAndPrune() } }() } func (s *Server) runAtSender() { ticker := time.NewTicker(s.config.AtSenderInterval) for { <-ticker.C if err := s.sendDelayedMessages(); err != nil { log.Printf("error sending scheduled messages: %s", err.Error()) } } } func (s *Server) runFirebaseKeepliver() { if s.firebase == nil { return } ticker := time.NewTicker(s.config.FirebaseKeepaliveInterval) for { <-ticker.C if err := s.firebase(newKeepaliveMessage(firebaseControlTopic)); err != nil { log.Printf("error sending Firebase keepalive message: %s", err.Error()) } } } 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()) } } } 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 err } 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) return s.visitors[ip] } v.seen = time.Now() return v } func (s *Server) inc(counter *int64) { s.mu.Lock() defer s.mu.Unlock() *counter++ } func (s *Server) fail(w http.ResponseWriter, r *http.Request, code int, err error) { log.Printf("[%s] %s - %d - %s", r.RemoteAddr, r.Method, code, err.Error()) w.WriteHeader(code) _, _ = io.WriteString(w, fmt.Sprintf("%s\n", http.StatusText(code))) }