92 lines
2.0 KiB
Go
92 lines
2.0 KiB
Go
package domainrouter
|
|
|
|
import (
|
|
"net/http"
|
|
"strings"
|
|
"sync"
|
|
"sync/atomic"
|
|
"time"
|
|
|
|
"github.com/rs/zerolog/log"
|
|
)
|
|
|
|
type Limiter struct {
|
|
current map[string]*atomic.Int64
|
|
max int
|
|
ticker *time.Ticker
|
|
refill int
|
|
m *sync.RWMutex
|
|
c chan string
|
|
}
|
|
|
|
func NewLimiter(maxRequests int, refills int, refillInterval time.Duration) Limiter {
|
|
return Limiter{
|
|
current: make(map[string]*atomic.Int64),
|
|
max: maxRequests,
|
|
ticker: time.NewTicker(refillInterval),
|
|
refill: refills,
|
|
m: &sync.RWMutex{},
|
|
c: make(chan string),
|
|
}
|
|
}
|
|
|
|
func (l *Limiter) Start() {
|
|
go l.Manage()
|
|
return
|
|
}
|
|
|
|
func (l *Limiter) Manage() {
|
|
for {
|
|
select {
|
|
case ip := <-l.c:
|
|
l.m.Lock()
|
|
if counter, ok := l.current[ip]; ok {
|
|
counter.Add(1)
|
|
} else {
|
|
counter := &atomic.Int64{}
|
|
l.current[ip] = counter
|
|
}
|
|
l.m.Unlock()
|
|
case <-l.ticker.C:
|
|
l.m.RLock()
|
|
for ip := range l.current {
|
|
n := l.current[ip].Add(int64(-l.refill))
|
|
if n < 0 {
|
|
l.current[ip].Store(0)
|
|
n = 0
|
|
}
|
|
log.Debug().Int64("bucket", n).Str("remote", ip).Msg("Updated limit")
|
|
}
|
|
l.m.RUnlock()
|
|
log.Debug().Msg("Refreshed Limits")
|
|
}
|
|
}
|
|
}
|
|
|
|
func (l *Limiter) RateLimiter(next http.Handler) http.Handler {
|
|
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
|
|
addr := strings.Split(r.RemoteAddr, ":")[0]
|
|
l.m.RLock()
|
|
count, ok := l.current[addr]
|
|
l.m.RUnlock()
|
|
if ok && int(count.Load()) >= l.max {
|
|
hj, ok := w.(http.Hijacker)
|
|
if !ok {
|
|
r.Body.Close()
|
|
log.Warn().Str("host", r.Host).Str("uri", r.RequestURI).Str("method", r.Method).Str("remote", addr).Msg("Rate limited")
|
|
return
|
|
}
|
|
conn, _, err := hj.Hijack()
|
|
if err != nil {
|
|
log.Error().Err(err).Str("host", r.Host).Str("uri", r.RequestURI).Str("method", r.Method).Str("remote", addr).Msg("Could not hijack connection")
|
|
}
|
|
|
|
log.Warn().Str("host", r.Host).Str("uri", r.RequestURI).Str("method", r.Method).Str("remote", addr).Msg("Rate limited")
|
|
conn.Close()
|
|
return
|
|
}
|
|
l.c <- addr
|
|
next.ServeHTTP(w, r)
|
|
})
|
|
}
|