275 lines
9.3 KiB
Go
275 lines
9.3 KiB
Go
package server
|
|
|
|
import (
|
|
"context"
|
|
"encoding/json"
|
|
"errors"
|
|
firebase "firebase.google.com/go/v4"
|
|
"firebase.google.com/go/v4/messaging"
|
|
"fmt"
|
|
"google.golang.org/api/option"
|
|
"heckel.io/ntfy/auth"
|
|
"heckel.io/ntfy/log"
|
|
"heckel.io/ntfy/util"
|
|
"strings"
|
|
)
|
|
|
|
const (
|
|
fcmMessageLimit = 4000
|
|
fcmApnsBodyMessageLimit = 100
|
|
)
|
|
|
|
var (
|
|
errFirebaseQuotaExceeded = errors.New("quota exceeded for Firebase messages to topic")
|
|
errFirebaseTemporarilyBanned = errors.New("visitor temporarily banned from using Firebase")
|
|
)
|
|
|
|
// firebaseClient is a generic client that formats and sends messages to Firebase.
|
|
// The actual Firebase implementation is implemented in firebaseSenderImpl, to make it testable.
|
|
type firebaseClient struct {
|
|
sender firebaseSender
|
|
auther auth.Auther
|
|
}
|
|
|
|
func newFirebaseClient(sender firebaseSender, auther auth.Auther) *firebaseClient {
|
|
return &firebaseClient{
|
|
sender: sender,
|
|
auther: auther,
|
|
}
|
|
}
|
|
|
|
func (c *firebaseClient) Send(v *visitor, m *message) error {
|
|
if err := v.FirebaseAllowed(); err != nil {
|
|
return errFirebaseTemporarilyBanned
|
|
}
|
|
fbm, err := toFirebaseMessage(m, c.auther)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
if log.IsTrace() {
|
|
log.Trace("%s Firebase message: %s", logMessagePrefix(v, m), util.MaybeMarshalJSON(fbm))
|
|
}
|
|
err = c.sender.Send(fbm)
|
|
if err == errFirebaseQuotaExceeded {
|
|
log.Warn("%s Firebase quota exceeded (likely for topic), temporarily denying Firebase access to visitor", logMessagePrefix(v, m))
|
|
v.FirebaseTemporarilyDeny()
|
|
}
|
|
return err
|
|
}
|
|
|
|
// firebaseSender is an interface that represents a client that can send to Firebase Cloud Messaging.
|
|
// In tests, this can be implemented with a mock.
|
|
type firebaseSender interface {
|
|
// Send sends a message to Firebase, or returns an error. It returns errFirebaseQuotaExceeded
|
|
// if a rate limit has reached.
|
|
Send(m *messaging.Message) error
|
|
}
|
|
|
|
// firebaseSenderImpl is a firebaseSender that actually talks to Firebase
|
|
type firebaseSenderImpl struct {
|
|
client *messaging.Client
|
|
}
|
|
|
|
func newFirebaseSender(credentialsFile string) (*firebaseSenderImpl, error) {
|
|
fb, err := firebase.NewApp(context.Background(), nil, option.WithCredentialsFile(credentialsFile))
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
client, err := fb.Messaging(context.Background())
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
return &firebaseSenderImpl{
|
|
client: client,
|
|
}, nil
|
|
}
|
|
|
|
func (c *firebaseSenderImpl) Send(m *messaging.Message) error {
|
|
_, err := c.client.Send(context.Background(), m)
|
|
if err != nil && messaging.IsQuotaExceeded(err) {
|
|
return errFirebaseQuotaExceeded
|
|
}
|
|
return err
|
|
}
|
|
|
|
// toFirebaseMessage converts a message to a Firebase message.
|
|
//
|
|
// Normal messages ("message"):
|
|
// - For Android, we can receive data messages from Firebase and process them as code, so we just send all fields
|
|
// in the "data" attribute. In the Android app, we then turn those into a notification and display it.
|
|
// - On iOS, we are not allowed to receive data-only messages, so we build messages with an "alert" (with title and
|
|
// message), and still send the rest of the data along in the "aps" attribute. We can then locally modify the
|
|
// message in the Notification Service Extension.
|
|
//
|
|
// Keepalive messages ("keepalive"):
|
|
// - On Android, we subscribe to the "~control" topic, which is used to restart the foreground service (if it died,
|
|
// e.g. after an app update). We send these keepalive messages regularly (see Config.FirebaseKeepaliveInterval).
|
|
// - On iOS, we subscribe to the "~poll" topic, which is used to poll all topics regularly. This is because iOS
|
|
// does not allow any background or scheduled activity at all.
|
|
//
|
|
// Poll request messages ("poll_request"):
|
|
// - Normal messages are turned into poll request messages if anonymous users are not allowed to read the message.
|
|
// On Android, this will trigger the app to poll the topic and thereby displaying new messages.
|
|
// - If UpstreamBaseURL is set, messages are forwarded as poll requests to an upstream server and then forwarded
|
|
// to Firebase here. This is mainly for iOS to support self-hosted servers.
|
|
func toFirebaseMessage(m *message, auther auth.Auther) (*messaging.Message, error) {
|
|
var data map[string]string // Mostly matches https://ntfy.sh/docs/subscribe/api/#json-message-format
|
|
var apnsConfig *messaging.APNSConfig
|
|
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,
|
|
}
|
|
apnsConfig = createAPNSBackgroundConfig(data)
|
|
case pollRequestEvent:
|
|
data = map[string]string{
|
|
"id": m.ID,
|
|
"time": fmt.Sprintf("%d", m.Time),
|
|
"event": m.Event,
|
|
"topic": m.Topic,
|
|
"message": m.Message,
|
|
"poll_id": m.PollID,
|
|
}
|
|
apnsConfig = createAPNSAlertConfig(m, data)
|
|
case messageEvent:
|
|
allowForward := true
|
|
if auther != nil {
|
|
allowForward = auther.Authorize(nil, m.Topic, auth.PermissionRead) == nil
|
|
}
|
|
if allowForward {
|
|
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, ","),
|
|
"click": m.Click,
|
|
"icon": m.Icon,
|
|
"title": m.Title,
|
|
"message": m.Message,
|
|
"encoding": m.Encoding,
|
|
}
|
|
if len(m.Actions) > 0 {
|
|
actions, err := json.Marshal(m.Actions)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
data["actions"] = string(actions)
|
|
}
|
|
if m.Attachment != nil {
|
|
data["attachment_name"] = m.Attachment.Name
|
|
data["attachment_type"] = m.Attachment.Type
|
|
data["attachment_size"] = fmt.Sprintf("%d", m.Attachment.Size)
|
|
data["attachment_expires"] = fmt.Sprintf("%d", m.Attachment.Expires)
|
|
data["attachment_url"] = m.Attachment.URL
|
|
}
|
|
apnsConfig = createAPNSAlertConfig(m, data)
|
|
} else {
|
|
// If anonymous read for a topic is not allowed, we cannot send the message along
|
|
// via Firebase. Instead, we send a "poll_request" message, asking the client to poll.
|
|
data = map[string]string{
|
|
"id": m.ID,
|
|
"time": fmt.Sprintf("%d", m.Time),
|
|
"event": pollRequestEvent,
|
|
"topic": m.Topic,
|
|
}
|
|
// TODO Handle APNS?
|
|
}
|
|
}
|
|
var androidConfig *messaging.AndroidConfig
|
|
if m.Priority >= 4 {
|
|
androidConfig = &messaging.AndroidConfig{
|
|
Priority: "high",
|
|
}
|
|
}
|
|
return maybeTruncateFCMMessage(&messaging.Message{
|
|
Topic: m.Topic,
|
|
Data: data,
|
|
Android: androidConfig,
|
|
APNS: apnsConfig,
|
|
}), nil
|
|
}
|
|
|
|
// maybeTruncateFCMMessage performs best-effort truncation of FCM messages.
|
|
// The docs say the limit is 4000 characters, but during testing it wasn't quite clear
|
|
// what fields matter; so we're just capping the serialized JSON to 4000 bytes.
|
|
func maybeTruncateFCMMessage(m *messaging.Message) *messaging.Message {
|
|
s, err := json.Marshal(m)
|
|
if err != nil {
|
|
return m
|
|
}
|
|
if len(s) > fcmMessageLimit {
|
|
over := len(s) - fcmMessageLimit + 16 // = len("truncated":"1",), sigh ...
|
|
message, ok := m.Data["message"]
|
|
if ok && len(message) > over {
|
|
m.Data["truncated"] = "1"
|
|
m.Data["message"] = message[:len(message)-over]
|
|
}
|
|
}
|
|
return m
|
|
}
|
|
|
|
// createAPNSAlertConfig creates an APNS config for iOS notifications that show up as an alert (only relevant for iOS).
|
|
// We must set the Alert struct ("alert"), and we need to set MutableContent ("mutable-content"), so the Notification Service
|
|
// Extension in iOS can modify the message.
|
|
func createAPNSAlertConfig(m *message, data map[string]string) *messaging.APNSConfig {
|
|
apnsData := make(map[string]interface{})
|
|
for k, v := range data {
|
|
apnsData[k] = v
|
|
}
|
|
return &messaging.APNSConfig{
|
|
Payload: &messaging.APNSPayload{
|
|
CustomData: apnsData,
|
|
Aps: &messaging.Aps{
|
|
MutableContent: true,
|
|
Alert: &messaging.ApsAlert{
|
|
Title: m.Title,
|
|
Body: maybeTruncateAPNSBodyMessage(m.Message),
|
|
},
|
|
},
|
|
},
|
|
}
|
|
}
|
|
|
|
// createAPNSBackgroundConfig creates an APNS config for a silent background message (only relevant for iOS). Apple only
|
|
// allows us to send 2-3 of these notifications per hour, and delivery not guaranteed. We use this only for the ~poll
|
|
// topic, which triggers the iOS app to poll all topics for changes.
|
|
//
|
|
// See https://developer.apple.com/documentation/usernotifications/setting_up_a_remote_notification_server/pushing_background_updates_to_your_app
|
|
func createAPNSBackgroundConfig(data map[string]string) *messaging.APNSConfig {
|
|
apnsData := make(map[string]interface{})
|
|
for k, v := range data {
|
|
apnsData[k] = v
|
|
}
|
|
return &messaging.APNSConfig{
|
|
Headers: map[string]string{
|
|
"apns-push-type": "background",
|
|
"apns-priority": "5",
|
|
},
|
|
Payload: &messaging.APNSPayload{
|
|
Aps: &messaging.Aps{
|
|
ContentAvailable: true,
|
|
},
|
|
CustomData: apnsData,
|
|
},
|
|
}
|
|
}
|
|
|
|
// maybeTruncateAPNSBodyMessage truncates the body for APNS.
|
|
//
|
|
// The "body" of the push notification can contain the entire message, which would count doubly for the overall length
|
|
// of the APNS payload. I set a limit of 100 characters before truncating the notification "body" with ellipsis.
|
|
// The message would not be changed (unless truncated for being too long). Note: if the payload is too large (>4KB),
|
|
// APNS will simply reject / discard the notification, meaning it will never arrive on the iOS device.
|
|
func maybeTruncateAPNSBodyMessage(s string) string {
|
|
if len(s) >= fcmApnsBodyMessageLimit {
|
|
over := len(s) - fcmApnsBodyMessageLimit + 3 // len("...")
|
|
return s[:len(s)-over] + "..."
|
|
}
|
|
return s
|
|
}
|