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Merge pull request #151 from slingamn/limits_refactor.3

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refactor connection limits and throttling
This commit is contained in:
Daniel Oaks 2017-10-10 09:36:30 +10:00 committed by GitHub
commit 79325d333e
6 changed files with 182 additions and 144 deletions
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4
irc/client.go
View File

@ -542,9 +542,7 @@ func (client *Client) destroy() {
ipaddr := client.IP()
// this check shouldn't be required but eh
if ipaddr != nil {
client.server.connectionLimitsMutex.Lock()
client.server.connectionLimits.RemoveClient(ipaddr)
client.server.connectionLimitsMutex.Unlock()
client.server.connectionLimiter.RemoveClient(ipaddr)
}
// alert monitors

56
irc/config.go
View File

@ -15,6 +15,7 @@ import (
"time"
"code.cloudfoundry.org/bytefmt"
"github.com/oragono/oragono/irc/connection_limits"
"github.com/oragono/oragono/irc/custime"
"github.com/oragono/oragono/irc/logger"
"github.com/oragono/oragono/irc/passwd"
@ -108,29 +109,6 @@ func (conf *OperConfig) PasswordBytes() []byte {
return bytes
}
// ConnectionLimitsConfig controls the automated connection limits.
type ConnectionLimitsConfig struct {
Enabled bool
CidrLenIPv4 int `yaml:"cidr-len-ipv4"`
CidrLenIPv6 int `yaml:"cidr-len-ipv6"`
IPsPerCidr int `yaml:"ips-per-subnet"`
Exempted []string
}
// ConnectionThrottleConfig controls the automated connection throttling.
type ConnectionThrottleConfig 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
}
// LineLenConfig controls line lengths.
type LineLenConfig struct {
Tags int
@ -173,19 +151,19 @@ type Config struct {
Server struct {
PassConfig
Password string
Name string
Listen []string
TLSListeners map[string]*TLSListenConfig `yaml:"tls-listeners"`
STS STSConfig
CheckIdent bool `yaml:"check-ident"`
MOTD string
MOTDFormatting bool `yaml:"motd-formatting"`
ProxyAllowedFrom []string `yaml:"proxy-allowed-from"`
MaxSendQString string `yaml:"max-sendq"`
MaxSendQBytes uint64
ConnectionLimits ConnectionLimitsConfig `yaml:"connection-limits"`
ConnectionThrottle ConnectionThrottleConfig `yaml:"connection-throttling"`
Password string
Name string
Listen []string
TLSListeners map[string]*TLSListenConfig `yaml:"tls-listeners"`
STS STSConfig
CheckIdent bool `yaml:"check-ident"`
MOTD string
MOTDFormatting bool `yaml:"motd-formatting"`
ProxyAllowedFrom []string `yaml:"proxy-allowed-from"`
MaxSendQString string `yaml:"max-sendq"`
MaxSendQBytes uint64
ConnectionLimiter connection_limits.LimiterConfig `yaml:"connection-limits"`
ConnectionThrottler connection_limits.ThrottlerConfig `yaml:"connection-throttling"`
}
Datastore struct {
@ -405,12 +383,12 @@ func LoadConfig(filename string) (config *Config, err error) {
return nil, fmt.Errorf("STS port is incorrect, should be 0 if disabled: %d", config.Server.STS.Port)
}
}
if config.Server.ConnectionThrottle.Enabled {
config.Server.ConnectionThrottle.Duration, err = time.ParseDuration(config.Server.ConnectionThrottle.DurationString)
if config.Server.ConnectionThrottler.Enabled {
config.Server.ConnectionThrottler.Duration, err = time.ParseDuration(config.Server.ConnectionThrottler.DurationString)
if err != nil {
return nil, fmt.Errorf("Could not parse connection-throttle duration: %s", err.Error())
}
config.Server.ConnectionThrottle.BanDuration, err = time.ParseDuration(config.Server.ConnectionThrottle.BanDurationString)
config.Server.ConnectionThrottler.BanDuration, err = time.ParseDuration(config.Server.ConnectionThrottler.BanDurationString)
if err != nil {
return nil, fmt.Errorf("Could not parse connection-throttle ban-duration: %s", err.Error())
}

71
irc/connection_limits.go → irc/connection_limits/limiter.go
View File

@ -1,20 +1,32 @@
// Copyright (c) 2016-2017 Daniel Oaks <daniel@danieloaks.net>
// released under the MIT license
package irc
package connection_limits
import (
"errors"
"fmt"
"net"
"sync"
)
// LimiterConfig controls the automated connection limits.
type LimiterConfig struct {
Enabled bool
CidrLenIPv4 int `yaml:"cidr-len-ipv4"`
CidrLenIPv6 int `yaml:"cidr-len-ipv6"`
IPsPerCidr int `yaml:"ips-per-subnet"`
Exempted []string
}
var (
errTooManyClients = errors.New("Too many clients in subnet")
)
// ConnectionLimits manages the automated client connection limits.
type ConnectionLimits struct {
// Limiter manages the automated client connection limits.
type Limiter struct {
sync.Mutex
enabled bool
ipv4Mask net.IPMask
ipv6Mask net.IPMask
@ -30,7 +42,7 @@ type ConnectionLimits struct {
}
// maskAddr masks the given IPv4/6 address with our cidr limit masks.
func (cl *ConnectionLimits) maskAddr(addr net.IP) net.IP {
func (cl *Limiter) maskAddr(addr net.IP) net.IP {
if addr.To4() == nil {
// IPv6 addr
addr = addr.Mask(cl.ipv6Mask)
@ -44,7 +56,10 @@ func (cl *ConnectionLimits) maskAddr(addr net.IP) net.IP {
// AddClient adds a client to our population if possible. If we can't, throws an error instead.
// 'force' is used to add already-existing clients (i.e. ones that are already on the network).
func (cl *ConnectionLimits) AddClient(addr net.IP, force bool) error {
func (cl *Limiter) AddClient(addr net.IP, force bool) error {
cl.Lock()
defer cl.Unlock()
if !cl.enabled {
return nil
}
@ -74,7 +89,10 @@ func (cl *ConnectionLimits) AddClient(addr net.IP, force bool) error {
}
// RemoveClient removes the given address from our population
func (cl *ConnectionLimits) RemoveClient(addr net.IP) {
func (cl *Limiter) RemoveClient(addr net.IP) {
cl.Lock()
defer cl.Unlock()
if !cl.enabled {
return
}
@ -88,35 +106,48 @@ func (cl *ConnectionLimits) RemoveClient(addr net.IP) {
}
}
// NewConnectionLimits returns a new connection limit handler.
func NewConnectionLimits(config ConnectionLimitsConfig) (*ConnectionLimits, error) {
var cl ConnectionLimits
cl.enabled = config.Enabled
// NewLimiter returns a new connection limit handler.
// The handler is functional, but disabled; it can be enabled via `ApplyConfig`.
func NewLimiter() *Limiter {
var cl Limiter
// initialize empty population; all other state is configurable
cl.population = make(map[string]int)
cl.exemptedIPs = make(map[string]bool)
cl.ipv4Mask = net.CIDRMask(config.CidrLenIPv4, 32)
cl.ipv6Mask = net.CIDRMask(config.CidrLenIPv6, 128)
// subnetLimit is explicitly NOT capped at a minimum of one.
// this is so that CL config can be used to allow ONLY clients from exempted IPs/nets
cl.subnetLimit = config.IPsPerCidr
return &cl
}
// ApplyConfig atomically applies a config update to a connection limit handler
func (cl *Limiter) ApplyConfig(config LimiterConfig) error {
// assemble exempted nets
exemptedIPs := make(map[string]bool)
var exemptedNets []net.IPNet
for _, cidr := range config.Exempted {
ipaddr := net.ParseIP(cidr)
_, netaddr, err := net.ParseCIDR(cidr)
if ipaddr == nil && err != nil {
return nil, fmt.Errorf("Could not parse exempted IP/network [%s]", cidr)
return fmt.Errorf("Could not parse exempted IP/network [%s]", cidr)
}
if ipaddr != nil {
cl.exemptedIPs[ipaddr.String()] = true
exemptedIPs[ipaddr.String()] = true
} else {
cl.exemptedNets = append(cl.exemptedNets, *netaddr)
exemptedNets = append(exemptedNets, *netaddr)
}
}
return &cl, nil
cl.Lock()
defer cl.Unlock()
cl.enabled = config.Enabled
cl.ipv4Mask = net.CIDRMask(config.CidrLenIPv4, 32)
cl.ipv6Mask = net.CIDRMask(config.CidrLenIPv6, 128)
// subnetLimit is explicitly NOT capped at a minimum of one.
// this is so that CL config can be used to allow ONLY clients from exempted IPs/nets
cl.subnetLimit = config.IPsPerCidr
cl.exemptedIPs = exemptedIPs
cl.exemptedNets = exemptedNets
return nil
}

99
irc/connection_throttling.go → irc/connection_limits/throttler.go
View File

@ -1,22 +1,39 @@
// Copyright (c) 2016-2017 Daniel Oaks <daniel@danieloaks.net>
// released under the MIT license
package irc
package connection_limits
import (
"fmt"
"net"
"sync"
"time"
)
// 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
ClientCount int
}
// ConnectionThrottle manages automated client connection throttling.
type ConnectionThrottle struct {
// Throttler manages automated client connection throttling.
type Throttler struct {
sync.RWMutex
enabled bool
ipv4Mask net.IPMask
ipv6Mask net.IPMask
@ -25,9 +42,8 @@ type ConnectionThrottle struct {
population map[string]ThrottleDetails
// used by the server to ban clients that go over this limit
BanDuration time.Duration
BanMessage string
BanMessageBytes []byte
banDuration time.Duration
banMessage string
// exemptedIPs holds IPs that are exempt from limits
exemptedIPs map[string]bool
@ -36,7 +52,7 @@ type ConnectionThrottle struct {
}
// maskAddr masks the given IPv4/6 address with our cidr limit masks.
func (ct *ConnectionThrottle) maskAddr(addr net.IP) net.IP {
func (ct *Throttler) maskAddr(addr net.IP) net.IP {
if addr.To4() == nil {
// IPv6 addr
addr = addr.Mask(ct.ipv6Mask)
@ -49,7 +65,10 @@ func (ct *ConnectionThrottle) maskAddr(addr net.IP) net.IP {
}
// ResetFor removes any existing count for the given address.
func (ct *ConnectionThrottle) ResetFor(addr net.IP) {
func (ct *Throttler) ResetFor(addr net.IP) {
ct.Lock()
defer ct.Unlock()
if !ct.enabled {
return
}
@ -61,7 +80,10 @@ func (ct *ConnectionThrottle) ResetFor(addr net.IP) {
}
// AddClient introduces a new client connection if possible. If we can't, throws an error instead.
func (ct *ConnectionThrottle) AddClient(addr net.IP) error {
func (ct *Throttler) AddClient(addr net.IP) error {
ct.Lock()
defer ct.Unlock()
if !ct.enabled {
return nil
}
@ -97,38 +119,63 @@ func (ct *ConnectionThrottle) AddClient(addr net.IP) error {
return nil
}
// NewConnectionThrottle returns a new client connection throttler.
func NewConnectionThrottle(config ConnectionThrottleConfig) (*ConnectionThrottle, error) {
var ct ConnectionThrottle
ct.enabled = config.Enabled
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
}
// NewThrottler returns a new client connection throttler.
// The throttler is functional, but disabled; it can be enabled via `ApplyConfig`.
func NewThrottler() *Throttler {
var ct Throttler
// initialize empty population; all other state is configurable
ct.population = make(map[string]ThrottleDetails)
ct.exemptedIPs = make(map[string]bool)
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
return &ct
}
// ApplyConfig atomically applies a config update to a throttler
func (ct *Throttler) ApplyConfig(config ThrottlerConfig) error {
// assemble exempted nets
exemptedIPs := make(map[string]bool)
var exemptedNets []net.IPNet
for _, cidr := range config.Exempted {
ipaddr := net.ParseIP(cidr)
_, netaddr, err := net.ParseCIDR(cidr)
if ipaddr == nil && err != nil {
return nil, fmt.Errorf("Could not parse exempted IP/network [%s]", cidr)
return fmt.Errorf("Could not parse exempted IP/network [%s]", cidr)
}
if ipaddr != nil {
ct.exemptedIPs[ipaddr.String()] = true
exemptedIPs[ipaddr.String()] = true
} else {
ct.exemptedNets = append(ct.exemptedNets, *netaddr)
exemptedNets = append(exemptedNets, *netaddr)
}
}
return &ct, nil
ct.Lock()
defer ct.Unlock()
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.exemptedIPs = exemptedIPs
ct.exemptedNets = exemptedNets
return nil
}

94
irc/server.go
View File

@ -24,6 +24,7 @@ import (
"github.com/goshuirc/irc-go/ircfmt"
"github.com/goshuirc/irc-go/ircmsg"
"github.com/oragono/oragono/irc/caps"
"github.com/oragono/oragono/irc/connection_limits"
"github.com/oragono/oragono/irc/isupport"
"github.com/oragono/oragono/irc/logger"
"github.com/oragono/oragono/irc/passwd"
@ -86,10 +87,8 @@ type Server struct {
commands chan Command
configFilename string
configurableStateMutex sync.RWMutex // generic protection for server state modified by rehash()
connectionLimits *ConnectionLimits
connectionLimitsMutex sync.Mutex // used when affecting the connection limiter, to make sure rehashing doesn't make things go out-of-whack
connectionThrottle *ConnectionThrottle
connectionThrottleMutex sync.Mutex // used when affecting the connection limiter, to make sure rehashing doesn't make things go out-of-whack
connectionLimiter *connection_limits.Limiter
connectionThrottler *connection_limits.Throttler
ctime time.Time
defaultChannelModes Modes
dlines *DLineManager
@ -145,19 +144,21 @@ func NewServer(config *Config, logger *logger.Manager) (*Server, error) {
// initialize data structures
server := &Server{
accounts: make(map[string]*ClientAccount),
channels: *NewChannelNameMap(),
clients: NewClientLookupSet(),
commands: make(chan Command),
listeners: make(map[string]*ListenerWrapper),
logger: logger,
monitorManager: NewMonitorManager(),
newConns: make(chan clientConn),
registeredChannels: make(map[string]*RegisteredChannel),
rehashSignal: make(chan os.Signal, 1),
signals: make(chan os.Signal, len(ServerExitSignals)),
snomasks: NewSnoManager(),
whoWas: NewWhoWasList(config.Limits.WhowasEntries),
accounts: make(map[string]*ClientAccount),
channels: *NewChannelNameMap(),
clients: NewClientLookupSet(),
commands: make(chan Command),
connectionLimiter: connection_limits.NewLimiter(),
connectionThrottler: connection_limits.NewThrottler(),
listeners: make(map[string]*ListenerWrapper),
logger: logger,
monitorManager: NewMonitorManager(),
newConns: make(chan clientConn),
registeredChannels: make(map[string]*RegisteredChannel),
rehashSignal: make(chan os.Signal, 1),
signals: make(chan os.Signal, len(ServerExitSignals)),
snomasks: NewSnoManager(),
whoWas: NewWhoWasList(config.Limits.WhowasEntries),
}
if err := server.applyConfig(config, true); err != nil {
@ -297,36 +298,38 @@ func (server *Server) checkBans(ipaddr net.IP) (banned bool, message string) {
// check DLINEs
isBanned, info := server.dlines.CheckIP(ipaddr)
if isBanned {
server.logger.Info("localconnect-ip", fmt.Sprintf("Client from %v rejected by d-line", ipaddr))
return true, info.BanMessage("You are banned from this server (%s)")
}
// check connection limits
server.connectionLimitsMutex.Lock()
err := server.connectionLimits.AddClient(ipaddr, false)
server.connectionLimitsMutex.Unlock()
err := server.connectionLimiter.AddClient(ipaddr, false)
if err != nil {
// too many connections from one client, tell the client and close the connection
server.logger.Info("localconnect-ip", fmt.Sprintf("Client from %v rejected for connection limit", ipaddr))
return true, "Too many clients from your network"
}
// check connection throttle
server.connectionThrottleMutex.Lock()
err = server.connectionThrottle.AddClient(ipaddr)
server.connectionThrottleMutex.Unlock()
err = server.connectionThrottler.AddClient(ipaddr)
if err != nil {
// too many connections too quickly from client, tell them and close the connection
duration := server.connectionThrottler.BanDuration()
length := &IPRestrictTime{
Duration: server.connectionThrottle.BanDuration,
Expires: time.Now().Add(server.connectionThrottle.BanDuration),
Duration: duration,
Expires: time.Now().Add(duration),
}
server.dlines.AddIP(ipaddr, length, server.connectionThrottle.BanMessage, "Exceeded automated connection throttle")
server.dlines.AddIP(ipaddr, length, server.connectionThrottler.BanMessage(), "Exceeded automated connection throttle")
// they're DLINE'd for 15 minutes or whatever, so we can reset the connection throttle now,
// and once their temporary DLINE is finished they can fill up the throttler again
server.connectionThrottle.ResetFor(ipaddr)
server.connectionThrottler.ResetFor(ipaddr)
// this might not show up properly on some clients, but our objective here is just to close it out before it has a load impact on us
return true, server.connectionThrottle.BanMessage
server.logger.Info(
"localconnect-ip",
fmt.Sprintf("Client from %v exceeded connection throttle, d-lining for %v", ipaddr, duration))
return true, server.connectionThrottler.BanMessage()
}
return false, ""
@ -1229,18 +1232,6 @@ func (server *Server) applyConfig(config *Config, initial bool) error {
return fmt.Errorf("Server name isn't valid [%s]: %s", config.Server.Name, err.Error())
}
// confirm connectionLimits are fine
connectionLimits, err := NewConnectionLimits(config.Server.ConnectionLimits)
if err != nil {
return fmt.Errorf("Error rehashing config file connection-limits: %s", err.Error())
}
// confirm connectionThrottler is fine
connectionThrottle, err := NewConnectionThrottle(config.Server.ConnectionThrottle)
if err != nil {
return fmt.Errorf("Error rehashing config file connection-throttle: %s", err.Error())
}
// confirm operator stuff all exists and is fine
operclasses, err := config.OperatorClasses()
if err != nil {
@ -1272,22 +1263,15 @@ func (server *Server) applyConfig(config *Config, initial bool) error {
// apply new PROXY command restrictions
server.proxyAllowedFrom = config.Server.ProxyAllowedFrom
// apply new connectionlimits
server.connectionLimitsMutex.Lock()
server.connectionLimits = connectionLimits
server.connectionThrottleMutex.Lock()
server.connectionThrottle = connectionThrottle
server.clients.ByNickMutex.RLock()
for _, client := range server.clients.ByNick {
ipaddr := client.IP()
if ipaddr != nil {
server.connectionLimits.AddClient(ipaddr, true)
}
err = server.connectionLimiter.ApplyConfig(config.Server.ConnectionLimiter)
if err != nil {
return err
}
err = server.connectionThrottler.ApplyConfig(config.Server.ConnectionThrottler)
if err != nil {
return err
}
server.clients.ByNickMutex.RUnlock()
server.connectionThrottleMutex.Unlock()
server.connectionLimitsMutex.Unlock()
// setup new and removed caps
addedCaps := caps.NewSet()

2
oragono.yaml
View File

@ -71,7 +71,7 @@ server:
# maximum number of connections per subnet
connection-limits:
# whether to throttle limits or not
# whether to enforce connection limits or not
enabled: true
# how wide the cidr should be for IPv4