ntfy/server/visitor.go
2022-01-08 15:47:08 -05:00

87 lines
1.9 KiB
Go

package server
import (
"errors"
"golang.org/x/time/rate"
"heckel.io/ntfy/util"
"sync"
"time"
)
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
ip string
requests *rate.Limiter
subscriptions *util.Limiter
emails *rate.Limiter
seen time.Time
mu sync.Mutex
}
func newVisitor(conf *Config, ip string) *visitor {
return &visitor{
config: conf,
ip: ip,
requests: rate.NewLimiter(rate.Every(conf.VisitorRequestLimitReplenish), conf.VisitorRequestLimitBurst),
subscriptions: util.NewLimiter(int64(conf.VisitorSubscriptionLimit)),
emails: rate.NewLimiter(rate.Every(conf.VisitorEmailLimitReplenish), conf.VisitorEmailLimitBurst),
seen: time.Now(),
}
}
func (v *visitor) IP() string {
return v.ip
}
func (v *visitor) RequestAllowed() error {
if !v.requests.Allow() {
return errVisitorLimitReached
}
return nil
}
func (v *visitor) EmailAllowed() error {
if !v.emails.Allow() {
return errVisitorLimitReached
}
return nil
}
func (v *visitor) SubscriptionAllowed() error {
v.mu.Lock()
defer v.mu.Unlock()
if err := v.subscriptions.Add(1); err != nil {
return errVisitorLimitReached
}
return nil
}
func (v *visitor) RemoveSubscription() {
v.mu.Lock()
defer v.mu.Unlock()
v.subscriptions.Sub(1)
}
func (v *visitor) Keepalive() {
v.mu.Lock()
defer v.mu.Unlock()
v.seen = time.Now()
}
func (v *visitor) Stale() bool {
v.mu.Lock()
defer v.mu.Unlock()
return time.Since(v.seen) > visitorExpungeAfter
}