fix #646

Includes a partially backwards-incompatible config change

irc/connection_limits/throttler.go

@@ -4,28 +4,9 @@
 package connection_limits
 
 import (
-	"fmt"
-	"net"
-	"sync"
 	"time"
-
-	"github.com/oragono/oragono/irc/utils"
 )
 
-// ThrottlerConfig controls the automated connection throttling.
-type ThrottlerConfig struct {
-	Enabled            bool
-	CidrLenIPv4        int           `yaml:"cidr-len-ipv4"`
-	CidrLenIPv6        int           `yaml:"cidr-len-ipv6"`
-	ConnectionsPerCidr int           `yaml:"max-connections"`
-	DurationString     string        `yaml:"duration"`
-	Duration           time.Duration `yaml:"duration-time"`
-	BanDurationString  string        `yaml:"ban-duration"`
-	BanDuration        time.Duration
-	BanMessage         string `yaml:"ban-message"`
-	Exempted           []string
-}
-
 // ThrottleDetails holds the connection-throttling details for a subnet/IP.
 type ThrottleDetails struct {
 	Start time.Time
@@ -68,111 +49,3 @@ func (g *GenericThrottle) touch(now time.Time) (throttled bool, remainingTime ti
 		return false, 0
 	}
 }
-
-// Throttler manages automated client connection throttling.
-type Throttler struct {
-	sync.RWMutex
-
-	enabled     bool
-	ipv4Mask    net.IPMask
-	ipv6Mask    net.IPMask
-	subnetLimit int
-	duration    time.Duration
-	population  map[string]ThrottleDetails
-
-	// used by the server to ban clients that go over this limit
-	banDuration time.Duration
-	banMessage  string
-
-	// exemptedNets holds networks that are exempt from limits
-	exemptedNets []net.IPNet
-}
-
-// ResetFor removes any existing count for the given address.
-func (ct *Throttler) ResetFor(addr net.IP) {
-	ct.Lock()
-	defer ct.Unlock()
-
-	if !ct.enabled {
-		return
-	}
-
-	// remove
-	addrString := addrToKey(addr, ct.ipv4Mask, ct.ipv6Mask)
-	delete(ct.population, addrString)
-}
-
-// AddClient introduces a new client connection if possible. If we can't, throws an error instead.
-func (ct *Throttler) AddClient(addr net.IP) error {
-	ct.Lock()
-	defer ct.Unlock()
-
-	if !ct.enabled {
-		return nil
-	}
-
-	// check exempted lists
-	if utils.IPInNets(addr, ct.exemptedNets) {
-		return nil
-	}
-
-	// check throttle
-	addrString := addrToKey(addr, ct.ipv4Mask, ct.ipv6Mask)
-
-	details := ct.population[addrString] // retrieve mutable throttle state from the map
-	// add in constant state to process the limiting operation
-	g := GenericThrottle{
-		ThrottleDetails: details,
-		Duration:        ct.duration,
-		Limit:           ct.subnetLimit,
-	}
-	throttled, _ := g.Touch()                     // actually check the limit
-	ct.population[addrString] = g.ThrottleDetails // store modified mutable state
-
-	if throttled {
-		return errTooManyClients
-	} else {
-		return nil
-	}
-}
-
-func (ct *Throttler) BanDuration() time.Duration {
-	ct.RLock()
-	defer ct.RUnlock()
-
-	return ct.banDuration
-}
-
-func (ct *Throttler) BanMessage() string {
-	ct.RLock()
-	defer ct.RUnlock()
-
-	return ct.banMessage
-}
-
-// ApplyConfig atomically applies a config update to a throttler
-func (ct *Throttler) ApplyConfig(config ThrottlerConfig) error {
-	// assemble exempted nets
-	exemptedNets, err := utils.ParseNetList(config.Exempted)
-	if err != nil {
-		return fmt.Errorf("Could not parse throttle exemption list: %v", err.Error())
-	}
-
-	ct.Lock()
-	defer ct.Unlock()
-
-	if ct.population == nil {
-		ct.population = make(map[string]ThrottleDetails)
-	}
-
-	ct.enabled = config.Enabled
-	ct.ipv4Mask = net.CIDRMask(config.CidrLenIPv4, 32)
-	ct.ipv6Mask = net.CIDRMask(config.CidrLenIPv6, 128)
-	ct.subnetLimit = config.ConnectionsPerCidr
-	ct.duration = config.Duration
-	ct.banDuration = config.BanDuration
-	ct.banMessage = config.BanMessage
-	ct.exemptedNets = exemptedNets
-
-	return nil
-}