ntfy/server/visitor.go
2022-12-20 21:18:33 -05:00

221 lines
6.3 KiB
Go

package server
import (
"errors"
"heckel.io/ntfy/auth"
"net/netip"
"sync"
"time"
"golang.org/x/time/rate"
"heckel.io/ntfy/util"
)
const (
// visitorExpungeAfter defines how long a visitor is active before it is removed from memory. This number
// has to be very high to prevent e-mail abuse, but it doesn't really affect the other limits anyway, since
// they are replenished faster (typically).
visitorExpungeAfter = 24 * time.Hour
)
var (
errVisitorLimitReached = errors.New("limit reached")
)
// visitor represents an API user, and its associated rate.Limiter used for rate limiting
type visitor struct {
config *Config
messageCache *messageCache
ip netip.Addr
user *auth.User
messages int64 // Number of messages sent
emails int64 // Number of emails sent
requestLimiter *rate.Limiter // Rate limiter for (almost) all requests (including messages)
emailsLimiter *rate.Limiter // Rate limiter for emails
subscriptionLimiter util.Limiter // Fixed limiter for active subscriptions (ongoing connections)
bandwidthLimiter util.Limiter
firebase time.Time // Next allowed Firebase message
seen time.Time
mu sync.Mutex
}
type visitorStats struct {
Basis string // "ip", "role" or "plan"
Messages int64
MessagesLimit int64
MessagesRemaining int64
Emails int64
EmailsLimit int64
EmailsRemaining int64
AttachmentTotalSize int64
AttachmentTotalSizeLimit int64
AttachmentTotalSizeRemaining int64
AttachmentFileSizeLimit int64
}
func newVisitor(conf *Config, messageCache *messageCache, ip netip.Addr, user *auth.User) *visitor {
var requestLimiter, emailsLimiter *rate.Limiter
var messages, emails int64
if user != nil {
messages = user.Stats.Messages
emails = user.Stats.Emails
}
if user != nil && user.Plan != nil {
requestLimiter = rate.NewLimiter(dailyLimitToRate(user.Plan.MessagesLimit), conf.VisitorRequestLimitBurst)
emailsLimiter = rate.NewLimiter(dailyLimitToRate(user.Plan.EmailsLimit), conf.VisitorEmailLimitBurst)
} else {
requestLimiter = rate.NewLimiter(rate.Every(conf.VisitorRequestLimitReplenish), conf.VisitorRequestLimitBurst)
emailsLimiter = rate.NewLimiter(rate.Every(conf.VisitorEmailLimitReplenish), conf.VisitorEmailLimitBurst)
}
return &visitor{
config: conf,
messageCache: messageCache,
ip: ip,
user: user,
messages: messages,
emails: emails,
requestLimiter: requestLimiter,
emailsLimiter: emailsLimiter,
subscriptionLimiter: util.NewFixedLimiter(int64(conf.VisitorSubscriptionLimit)),
bandwidthLimiter: util.NewBytesLimiter(conf.VisitorAttachmentDailyBandwidthLimit, 24*time.Hour),
firebase: time.Unix(0, 0),
seen: time.Now(),
}
}
func (v *visitor) RequestAllowed() error {
if !v.requestLimiter.Allow() {
return errVisitorLimitReached
}
return nil
}
func (v *visitor) FirebaseAllowed() error {
v.mu.Lock()
defer v.mu.Unlock()
if time.Now().Before(v.firebase) {
return errVisitorLimitReached
}
return nil
}
func (v *visitor) FirebaseTemporarilyDeny() {
v.mu.Lock()
defer v.mu.Unlock()
v.firebase = time.Now().Add(v.config.FirebaseQuotaExceededPenaltyDuration)
}
func (v *visitor) EmailAllowed() error {
if !v.emailsLimiter.Allow() {
return errVisitorLimitReached
}
return nil
}
func (v *visitor) SubscriptionAllowed() error {
v.mu.Lock()
defer v.mu.Unlock()
if err := v.subscriptionLimiter.Allow(1); err != nil {
return errVisitorLimitReached
}
return nil
}
func (v *visitor) RemoveSubscription() {
v.mu.Lock()
defer v.mu.Unlock()
v.subscriptionLimiter.Allow(-1)
}
func (v *visitor) Keepalive() {
v.mu.Lock()
defer v.mu.Unlock()
v.seen = time.Now()
}
func (v *visitor) BandwidthLimiter() util.Limiter {
return v.bandwidthLimiter
}
func (v *visitor) Stale() bool {
v.mu.Lock()
defer v.mu.Unlock()
return time.Since(v.seen) > visitorExpungeAfter
}
func (v *visitor) IncrMessages() {
v.mu.Lock()
defer v.mu.Unlock()
v.messages++
if v.user != nil {
v.user.Stats.Messages = v.messages
}
}
func (v *visitor) IncrEmails() {
v.mu.Lock()
defer v.mu.Unlock()
v.emails++
if v.user != nil {
v.user.Stats.Emails = v.emails
}
}
func (v *visitor) Stats() (*visitorStats, error) {
v.mu.Lock()
messages := v.messages
emails := v.emails
v.mu.Unlock()
stats := &visitorStats{}
if v.user != nil && v.user.Role == auth.RoleAdmin {
stats.Basis = "role"
stats.MessagesLimit = 0
stats.EmailsLimit = 0
stats.AttachmentTotalSizeLimit = 0
stats.AttachmentFileSizeLimit = 0
} else if v.user != nil && v.user.Plan != nil {
stats.Basis = "plan"
stats.MessagesLimit = v.user.Plan.MessagesLimit
stats.EmailsLimit = v.user.Plan.EmailsLimit
stats.AttachmentTotalSizeLimit = v.user.Plan.AttachmentTotalSizeLimit
stats.AttachmentFileSizeLimit = v.user.Plan.AttachmentFileSizeLimit
} else {
stats.Basis = "ip"
stats.MessagesLimit = replenishDurationToDailyLimit(v.config.VisitorRequestLimitReplenish)
stats.EmailsLimit = replenishDurationToDailyLimit(v.config.VisitorEmailLimitReplenish)
stats.AttachmentTotalSizeLimit = v.config.VisitorAttachmentTotalSizeLimit
stats.AttachmentFileSizeLimit = v.config.AttachmentFileSizeLimit
}
var attachmentsBytesUsed int64
var err error
if v.user != nil {
attachmentsBytesUsed, err = v.messageCache.AttachmentBytesUsedByUser(v.user.Name)
} else {
attachmentsBytesUsed, err = v.messageCache.AttachmentBytesUsedBySender(v.ip.String())
}
if err != nil {
return nil, err
}
stats.Messages = messages
stats.MessagesRemaining = zeroIfNegative(stats.MessagesLimit - stats.Messages)
stats.Emails = emails
stats.EmailsRemaining = zeroIfNegative(stats.EmailsLimit - stats.Emails)
stats.AttachmentTotalSize = attachmentsBytesUsed
stats.AttachmentTotalSizeRemaining = zeroIfNegative(stats.AttachmentTotalSizeLimit - stats.AttachmentTotalSize)
return stats, nil
}
func zeroIfNegative(value int64) int64 {
if value < 0 {
return 0
}
return value
}
func replenishDurationToDailyLimit(duration time.Duration) int64 {
return int64(24 * time.Hour / duration)
}
func dailyLimitToRate(limit int64) rate.Limit {
return rate.Limit(limit) * rate.Every(24*time.Hour)
}