part_of_check.go

func (acl *ACL) checkServer(ip string) bool {
	type Params struct {
		IP   string `url:"ip"`
		Name string `url:"name"`
	}

	ops := requestOps // To check laer
	if _, found := acl.rejected.Get(ip); found {
		log.Printf("In rejected %s", ip)
		return false
	}

	params := &Params{IP: ip, Name: configuration.Name}
	request, _ := sling.New().Base(configuration.Server).Get("/ip_enabled").QueryStruct(params).Request()

	// Avoid request storms to the server
	requestMutex.Lock()
	defer requestMutex.Unlock()

	if ops != requestOps { // Another thread made a request, check again locally
		if _, found := acl.authorized.Get(ip); found {
			return true
		}
	}

	resp, err := http.DefaultClient.Do(request)
	requestOps++

	if err == nil {
		defer resp.Body.Close()
		if resp.StatusCode == 200 {
			acl.add(ip, ACCESS_CLIENT, 3600) // One hour for IPs authorized from the server
			return true
		}
	}
	acl.rejected.Set(ip, true, cache.DefaultExpiration)
	return false
}