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Merge pull request #1445 from slingamn/flatiptypes.5

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introduce "flat ip" representations
This commit is contained in:
Shivaram Lingamneni 2020-12-08 20:50:31 -08:00 committed by GitHub
commit 58edabf5c3
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14 changed files with 535 additions and 137 deletions
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1
Makefile
View File

@ -25,6 +25,7 @@ test:
cd irc/cloaks && go test . && go vet .
cd irc/connection_limits && go test . && go vet .
cd irc/email && go test . && go vet .
cd irc/flatip && go test . && go vet .
cd irc/history && go test . && go vet .
cd irc/isupport && go test . && go vet .
cd irc/migrations && go test . && go vet .

3
default.yaml
View File

@ -247,9 +247,6 @@ server:
window: 10m
# maximum number of new connections per IP/CIDR within the given duration
max-connections-per-window: 32
# how long to ban offenders for. after banning them, the number of connections is
# reset, which lets you use /UNDLINE to unban people
throttle-ban-duration: 10m
# how wide the CIDR should be for IPv4 (a /32 is a fully specified IPv4 address)
cidr-len-ipv4: 32

3
irc/client.go
View File

@ -21,6 +21,7 @@ import (
ident "github.com/oragono/go-ident"
"github.com/oragono/oragono/irc/caps"
"github.com/oragono/oragono/irc/connection_limits"
"github.com/oragono/oragono/irc/flatip"
"github.com/oragono/oragono/irc/history"
"github.com/oragono/oragono/irc/modes"
"github.com/oragono/oragono/irc/sno"
@ -1477,7 +1478,7 @@ func (client *Client) destroy(session *Session) {
if session.proxiedIP != nil {
ip = session.proxiedIP
}
client.server.connectionLimiter.RemoveClient(ip)
client.server.connectionLimiter.RemoveClient(flatip.FromNetIP(ip))
source = ip.String()
}
client.server.logger.Info("connect-ip", fmt.Sprintf("disconnecting session of %s from %s", details.nick, source))

102
irc/connection_limits/limiter.go
View File

@ -4,12 +4,13 @@
package connection_limits
import (
"crypto/md5"
"errors"
"fmt"
"net"
"sync"
"time"
"github.com/oragono/oragono/irc/flatip"
"github.com/oragono/oragono/irc/utils"
)
@ -26,10 +27,15 @@ type CustomLimitConfig struct {
// tuples the key-value pair of a CIDR and its custom limit/throttle values
type customLimit struct {
name string
name [16]byte
maxConcurrent int
maxPerWindow int
nets []net.IPNet
nets []flatip.IPNet
}
type limiterKey struct {
maskedIP flatip.IP
prefixLen uint8 // 0 for the fake nets we generate for custom limits
}
// LimiterConfig controls the automated connection limits.
@ -41,8 +47,7 @@ type rawLimiterConfig struct {
Throttle bool
Window time.Duration
MaxPerWindow int `yaml:"max-connections-per-window"`
BanDuration time.Duration `yaml:"throttle-ban-duration"`
MaxPerWindow int `yaml:"max-connections-per-window"`
CidrLenIPv4 int `yaml:"cidr-len-ipv4"`
CidrLenIPv6 int `yaml:"cidr-len-ipv6"`
@ -55,9 +60,7 @@ type rawLimiterConfig struct {
type LimiterConfig struct {
rawLimiterConfig
ipv4Mask net.IPMask
ipv6Mask net.IPMask
exemptedNets []net.IPNet
exemptedNets []flatip.IPNet
customLimits []customLimit
}
@ -69,15 +72,19 @@ func (config *LimiterConfig) UnmarshalYAML(unmarshal func(interface{}) error) (e
}
func (config *LimiterConfig) postprocess() (err error) {
config.exemptedNets, err = utils.ParseNetList(config.Exempted)
exemptedNets, err := utils.ParseNetList(config.Exempted)
if err != nil {
return fmt.Errorf("Could not parse limiter exemption list: %v", err.Error())
}
config.exemptedNets = make([]flatip.IPNet, len(exemptedNets))
for i, exempted := range exemptedNets {
config.exemptedNets[i] = flatip.FromNetIPNet(exempted)
}
for identifier, customLimitConf := range config.CustomLimits {
nets := make([]net.IPNet, len(customLimitConf.Nets))
nets := make([]flatip.IPNet, len(customLimitConf.Nets))
for i, netStr := range customLimitConf.Nets {
normalizedNet, err := utils.NormalizedNetFromString(netStr)
normalizedNet, err := flatip.ParseToNormalizedNet(netStr)
if err != nil {
return fmt.Errorf("Bad net %s in custom-limits block %s: %w", netStr, identifier, err)
}
@ -86,23 +93,20 @@ func (config *LimiterConfig) postprocess() (err error) {
if len(customLimitConf.Nets) == 0 {
// see #1421: this is the legacy config format where the
// dictionary key of the block is a CIDR string
normalizedNet, err := utils.NormalizedNetFromString(identifier)
normalizedNet, err := flatip.ParseToNormalizedNet(identifier)
if err != nil {
return fmt.Errorf("Custom limit block %s has no defined nets", identifier)
}
nets = []net.IPNet{normalizedNet}
nets = []flatip.IPNet{normalizedNet}
}
config.customLimits = append(config.customLimits, customLimit{
maxConcurrent: customLimitConf.MaxConcurrent,
maxPerWindow: customLimitConf.MaxPerWindow,
name: "*" + identifier,
name: md5.Sum([]byte(identifier)),
nets: nets,
})
}
config.ipv4Mask = net.CIDRMask(config.CidrLenIPv4, 32)
config.ipv6Mask = net.CIDRMask(config.CidrLenIPv6, 128)
return nil
}
@ -113,53 +117,56 @@ type Limiter struct {
config *LimiterConfig
// IP/CIDR -> count of clients connected from there:
limiter map[string]int
limiter map[limiterKey]int
// IP/CIDR -> throttle state:
throttler map[string]ThrottleDetails
throttler map[limiterKey]ThrottleDetails
}
// addrToKey canonicalizes `addr` to a string key, and returns
// the relevant connection limit and throttle max-per-window values
func (cl *Limiter) addrToKey(addr net.IP) (key string, limit int, throttle int) {
// `key` will be a CIDR string like "8.8.8.8/32" or "2001:0db8::/32"
func (cl *Limiter) addrToKey(addr flatip.IP) (key limiterKey, limit int, throttle int) {
for _, custom := range cl.config.customLimits {
for _, net := range custom.nets {
if net.Contains(addr) {
return custom.name, custom.maxConcurrent, custom.maxPerWindow
return limiterKey{maskedIP: custom.name, prefixLen: 0}, custom.maxConcurrent, custom.maxPerWindow
}
}
}
var ipNet net.IPNet
addrv4 := addr.To4()
if addrv4 != nil {
ipNet = net.IPNet{
IP: addrv4.Mask(cl.config.ipv4Mask),
Mask: cl.config.ipv4Mask,
}
var prefixLen int
if addr.IsIPv4() {
prefixLen = cl.config.CidrLenIPv4
addr = addr.Mask(prefixLen, 32)
prefixLen += 96
} else {
ipNet = net.IPNet{
IP: addr.Mask(cl.config.ipv6Mask),
Mask: cl.config.ipv6Mask,
}
prefixLen = cl.config.CidrLenIPv6
addr = addr.Mask(prefixLen, 128)
}
return ipNet.String(), cl.config.MaxConcurrent, cl.config.MaxPerWindow
return limiterKey{maskedIP: addr, prefixLen: uint8(prefixLen)}, cl.config.MaxConcurrent, cl.config.MaxPerWindow
}
// AddClient adds a client to our population if possible. If we can't, throws an error instead.
func (cl *Limiter) AddClient(addr net.IP) error {
func (cl *Limiter) AddClient(addr flatip.IP) error {
cl.Lock()
defer cl.Unlock()
// we don't track populations for exempted addresses or nets - this is by design
if utils.IPInNets(addr, cl.config.exemptedNets) {
if flatip.IPInNets(addr, cl.config.exemptedNets) {
return nil
}
addrString, maxConcurrent, maxPerWindow := cl.addrToKey(addr)
// XXX check throttle first; if we checked limit first and then checked throttle,
// we'd have to decrement the limit on an unsuccessful throttle check
// check limiter
var count int
if cl.config.Count {
count = cl.limiter[addrString] + 1
if count > maxConcurrent {
return ErrLimitExceeded
}
}
if cl.config.Throttle {
details := cl.throttler[addrString] // retrieve mutable throttle state from the map
// add in constant state to process the limiting operation
@ -171,16 +178,13 @@ func (cl *Limiter) AddClient(addr net.IP) error {
throttled, _ := g.Touch() // actually check the limit
cl.throttler[addrString] = g.ThrottleDetails // store modified mutable state
if throttled {
// back out the limiter add
return ErrThrottleExceeded
}
}
// now check limiter
// success, record in limiter
if cl.config.Count {
count := cl.limiter[addrString] + 1
if count > maxConcurrent {
return ErrLimitExceeded
}
cl.limiter[addrString] = count
}
@ -188,11 +192,11 @@ func (cl *Limiter) AddClient(addr net.IP) error {
}
// RemoveClient removes the given address from our population
func (cl *Limiter) RemoveClient(addr net.IP) {
func (cl *Limiter) RemoveClient(addr flatip.IP) {
cl.Lock()
defer cl.Unlock()
if !cl.config.Count || utils.IPInNets(addr, cl.config.exemptedNets) {
if !cl.config.Count || flatip.IPInNets(addr, cl.config.exemptedNets) {
return
}
@ -206,11 +210,11 @@ func (cl *Limiter) RemoveClient(addr net.IP) {
}
// ResetThrottle resets the throttle count for an IP
func (cl *Limiter) ResetThrottle(addr net.IP) {
func (cl *Limiter) ResetThrottle(addr flatip.IP) {
cl.Lock()
defer cl.Unlock()
if !cl.config.Throttle || utils.IPInNets(addr, cl.config.exemptedNets) {
if !cl.config.Throttle || flatip.IPInNets(addr, cl.config.exemptedNets) {
return
}
@ -224,10 +228,10 @@ func (cl *Limiter) ApplyConfig(config *LimiterConfig) {
defer cl.Unlock()
if cl.limiter == nil {
cl.limiter = make(map[string]int)
cl.limiter = make(map[limiterKey]int)
}
if cl.throttler == nil {
cl.throttler = make(map[string]ThrottleDetails)
cl.throttler = make(map[limiterKey]ThrottleDetails)
}
cl.config = config

25
irc/connection_limits/limiter_test.go
View File

@ -4,15 +4,17 @@
package connection_limits
import (
"net"
"crypto/md5"
"testing"
"time"
"github.com/oragono/oragono/irc/flatip"
)
func easyParseIP(ipstr string) (result net.IP) {
result = net.ParseIP(ipstr)
if result == nil {
panic(ipstr)
func easyParseIP(ipstr string) (result flatip.IP) {
result, err := flatip.ParseIP(ipstr)
if err != nil {
panic(err)
}
return
}
@ -47,18 +49,23 @@ func TestKeying(t *testing.T) {
var limiter Limiter
limiter.ApplyConfig(&config)
// an ipv4 /32 looks like a /128 to us after applying the 4-in-6 mapping
key, maxConc, maxWin := limiter.addrToKey(easyParseIP("1.1.1.1"))
assertEqual(key, "1.1.1.1/32", t)
assertEqual(key.prefixLen, uint8(128), t)
assertEqual(key.maskedIP[12:], []byte{1, 1, 1, 1}, t)
assertEqual(maxConc, 4, t)
assertEqual(maxWin, 8, t)
key, maxConc, maxWin = limiter.addrToKey(easyParseIP("2607:5301:201:3100::7426"))
assertEqual(key, "2607:5301:201:3100::/64", t)
testIPv6 := easyParseIP("2607:5301:201:3100::7426")
key, maxConc, maxWin = limiter.addrToKey(testIPv6)
assertEqual(key.prefixLen, uint8(64), t)
assertEqual(flatip.IP(key.maskedIP), easyParseIP("2607:5301:201:3100::"), t)
assertEqual(maxConc, 4, t)
assertEqual(maxWin, 8, t)
key, maxConc, maxWin = limiter.addrToKey(easyParseIP("8.8.4.4"))
assertEqual(key, "*google", t)
assertEqual(key.prefixLen, uint8(0), t)
assertEqual([16]byte(key.maskedIP), md5.Sum([]byte("google")), t)
assertEqual(maxConc, 128, t)
assertEqual(maxWin, 256, t)
}

19
irc/connection_limits/throttler_test.go
View File

@ -4,7 +4,6 @@
package connection_limits
import (
"net"
"reflect"
"testing"
"time"
@ -83,7 +82,7 @@ func makeTestThrottler(v4len, v6len int) *Limiter {
func TestConnectionThrottle(t *testing.T) {
throttler := makeTestThrottler(32, 64)
addr := net.ParseIP("8.8.8.8")
addr := easyParseIP("8.8.8.8")
for i := 0; i < 3; i += 1 {
err := throttler.AddClient(addr)
@ -97,14 +96,14 @@ func TestConnectionThrottleIPv6(t *testing.T) {
throttler := makeTestThrottler(32, 64)
var err error
err = throttler.AddClient(net.ParseIP("2001:0db8::1"))
err = throttler.AddClient(easyParseIP("2001:0db8::1"))
assertEqual(err, nil, t)
err = throttler.AddClient(net.ParseIP("2001:0db8::2"))
err = throttler.AddClient(easyParseIP("2001:0db8::2"))
assertEqual(err, nil, t)
err = throttler.AddClient(net.ParseIP("2001:0db8::3"))
err = throttler.AddClient(easyParseIP("2001:0db8::3"))
assertEqual(err, nil, t)
err = throttler.AddClient(net.ParseIP("2001:0db8::4"))
err = throttler.AddClient(easyParseIP("2001:0db8::4"))
assertEqual(err, ErrThrottleExceeded, t)
}
@ -112,13 +111,13 @@ func TestConnectionThrottleIPv4(t *testing.T) {
throttler := makeTestThrottler(24, 64)
var err error
err = throttler.AddClient(net.ParseIP("192.168.1.101"))
err = throttler.AddClient(easyParseIP("192.168.1.101"))
assertEqual(err, nil, t)
err = throttler.AddClient(net.ParseIP("192.168.1.102"))
err = throttler.AddClient(easyParseIP("192.168.1.102"))
assertEqual(err, nil, t)
err = throttler.AddClient(net.ParseIP("192.168.1.103"))
err = throttler.AddClient(easyParseIP("192.168.1.103"))
assertEqual(err, nil, t)
err = throttler.AddClient(net.ParseIP("192.168.1.104"))
err = throttler.AddClient(easyParseIP("192.168.1.104"))
assertEqual(err, ErrThrottleExceeded, t)
}

73
irc/dline.go
View File

@ -11,6 +11,7 @@ import (
"sync"
"time"
"github.com/oragono/oragono/irc/flatip"
"github.com/oragono/oragono/irc/utils"
"github.com/tidwall/buntdb"
)
@ -54,34 +55,22 @@ func (info IPBanInfo) BanMessage(message string) string {
return message
}
// dLineNet contains the net itself and expiration time for a given network.
type dLineNet struct {
// Network is the network that is blocked.
// This is always an IPv6 CIDR; IPv4 CIDRs are translated with the 4-in-6 prefix,
// individual IPv4 and IPV6 addresses are translated to the relevant /128.
Network net.IPNet
// Info contains information on the ban.
Info IPBanInfo
}
// DLineManager manages and dlines.
type DLineManager struct {
sync.RWMutex // tier 1
persistenceMutex sync.Mutex // tier 2
// networks that are dlined:
// XXX: the keys of this map (which are also the database persistence keys)
// are the human-readable representations returned by NetToNormalizedString
networks map[string]dLineNet
networks map[flatip.IPNet]IPBanInfo
// this keeps track of expiration timers for temporary bans
expirationTimers map[string]*time.Timer
expirationTimers map[flatip.IPNet]*time.Timer
server *Server
}
// NewDLineManager returns a new DLineManager.
func NewDLineManager(server *Server) *DLineManager {
var dm DLineManager
dm.networks = make(map[string]dLineNet)
dm.expirationTimers = make(map[string]*time.Timer)
dm.networks = make(map[flatip.IPNet]IPBanInfo)
dm.expirationTimers = make(map[flatip.IPNet]*time.Timer)
dm.server = server
dm.loadFromDatastore()
@ -96,9 +85,8 @@ func (dm *DLineManager) AllBans() map[string]IPBanInfo {
dm.RLock()
defer dm.RUnlock()
// map keys are already the human-readable forms, just return a copy of the map
for key, info := range dm.networks {
allb[key] = info.Info
allb[key.String()] = info
}
return allb
@ -122,9 +110,9 @@ func (dm *DLineManager) AddNetwork(network net.IPNet, duration time.Duration, re
return dm.persistDline(id, info)
}
func (dm *DLineManager) addNetworkInternal(network net.IPNet, info IPBanInfo) (id string) {
network = utils.NormalizeNet(network)
id = utils.NetToNormalizedString(network)
func (dm *DLineManager) addNetworkInternal(network net.IPNet, info IPBanInfo) (id flatip.IPNet) {
flatnet := flatip.FromNetIPNet(network)
id = flatnet
var timeLeft time.Duration
if info.Duration != 0 {
@ -137,12 +125,9 @@ func (dm *DLineManager) addNetworkInternal(network net.IPNet, info IPBanInfo) (i
dm.Lock()
defer dm.Unlock()
dm.networks[id] = dLineNet{
Network: network,
Info: info,
}
dm.networks[flatnet] = info
dm.cancelTimer(id)
dm.cancelTimer(flatnet)
if info.Duration == 0 {
return
@ -154,29 +139,29 @@ func (dm *DLineManager) addNetworkInternal(network net.IPNet, info IPBanInfo) (i
dm.Lock()
defer dm.Unlock()
netBan, ok := dm.networks[id]
if ok && netBan.Info.TimeCreated.Equal(timeCreated) {
delete(dm.networks, id)
banInfo, ok := dm.networks[flatnet]
if ok && banInfo.TimeCreated.Equal(timeCreated) {
delete(dm.networks, flatnet)
// TODO(slingamn) here's where we'd remove it from the radix tree
delete(dm.expirationTimers, id)
delete(dm.expirationTimers, flatnet)
}
}
dm.expirationTimers[id] = time.AfterFunc(timeLeft, processExpiration)
dm.expirationTimers[flatnet] = time.AfterFunc(timeLeft, processExpiration)
return
}
func (dm *DLineManager) cancelTimer(id string) {
oldTimer := dm.expirationTimers[id]
func (dm *DLineManager) cancelTimer(flatnet flatip.IPNet) {
oldTimer := dm.expirationTimers[flatnet]
if oldTimer != nil {
oldTimer.Stop()
delete(dm.expirationTimers, id)
delete(dm.expirationTimers, flatnet)
}
}
func (dm *DLineManager) persistDline(id string, info IPBanInfo) error {
func (dm *DLineManager) persistDline(id flatip.IPNet, info IPBanInfo) error {
// save in datastore
dlineKey := fmt.Sprintf(keyDlineEntry, id)
dlineKey := fmt.Sprintf(keyDlineEntry, id.String())
// assemble json from ban info
b, err := json.Marshal(info)
if err != nil {
@ -199,8 +184,8 @@ func (dm *DLineManager) persistDline(id string, info IPBanInfo) error {
return err
}
func (dm *DLineManager) unpersistDline(id string) error {
dlineKey := fmt.Sprintf(keyDlineEntry, id)
func (dm *DLineManager) unpersistDline(id flatip.IPNet) error {
dlineKey := fmt.Sprintf(keyDlineEntry, id.String())
return dm.server.store.Update(func(tx *buntdb.Tx) error {
_, err := tx.Delete(dlineKey)
return err
@ -212,7 +197,7 @@ func (dm *DLineManager) RemoveNetwork(network net.IPNet) error {
dm.persistenceMutex.Lock()
defer dm.persistenceMutex.Unlock()
id := utils.NetToNormalizedString(utils.NormalizeNet(network))
id := flatip.FromNetIPNet(network)
present := func() bool {
dm.Lock()
@ -241,8 +226,7 @@ func (dm *DLineManager) RemoveIP(addr net.IP) error {
}
// CheckIP returns whether or not an IP address was banned, and how long it is banned for.
func (dm *DLineManager) CheckIP(addr net.IP) (isBanned bool, info IPBanInfo) {
addr = addr.To16() // almost certainly unnecessary
func (dm *DLineManager) CheckIP(addr flatip.IP) (isBanned bool, info IPBanInfo) {
if addr.IsLoopback() {
return // #671
}
@ -252,13 +236,12 @@ func (dm *DLineManager) CheckIP(addr net.IP) (isBanned bool, info IPBanInfo) {
// check networks
// TODO(slingamn) use a radix tree as the data plane for this
for _, netBan := range dm.networks {
if netBan.Network.Contains(addr) {
return true, netBan.Info
for flatnet, info := range dm.networks {
if flatnet.Contains(addr) {
return true, info
}
}
// no matches!
isBanned = false
return
}

33
irc/flatip/adhoc.go Normal file
View File

@ -0,0 +1,33 @@
// Copyright 2020 Shivaram Lingamneni <slingamn@cs.stanford.edu>
// Released under the MIT license
package flatip
// begin ad-hoc utilities
// ParseToNormalizedNet attempts to interpret a string either as an IP
// network in CIDR notation, returning an IPNet, or as an IP address,
// returning an IPNet that contains only that address.
func ParseToNormalizedNet(netstr string) (ipnet IPNet, err error) {
_, ipnet, err = ParseCIDR(netstr)
if err == nil {
return
}
ip, err := ParseIP(netstr)
if err == nil {
ipnet.IP = ip
ipnet.PrefixLen = 128
}
return
}
// IPInNets is a convenience function for testing whether an IP is contained
// in any member of a slice of IPNet's.
func IPInNets(addr IP, nets []IPNet) bool {
for _, net := range nets {
if net.Contains(addr) {
return true
}
}
return false
}

202
irc/flatip/flatip.go Normal file
View File

@ -0,0 +1,202 @@
// Copyright 2020 Shivaram Lingamneni <slingamn@cs.stanford.edu>
// Copyright 2009 The Go Authors
// Released under the MIT license
package flatip
import (
"bytes"
"errors"
"net"
)
var (
v4InV6Prefix = []byte{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xff, 0xff}
IPv6loopback = IP{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1}
IPv6zero = IP{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}
IPv4zero = IP{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xff, 0xff, 0, 0, 0, 0}
ErrInvalidIPString = errors.New("String could not be interpreted as an IP address")
)
// packed versions of net.IP and net.IPNet; these are pure value types,
// so they can be compared with == and used as map keys.
// IP is a 128-bit representation of an IP address, using the 4-in-6 mapping
// to represent IPv4 addresses.
type IP [16]byte
// IPNet is a IP network. In a valid value, all bits after PrefixLen are zeroes.
type IPNet struct {
IP
PrefixLen uint8
}
// NetIP converts an IP into a net.IP.
func (ip IP) NetIP() (result net.IP) {
result = make(net.IP, 16)
copy(result[:], ip[:])
return
}
// FromNetIP converts a net.IP into an IP.
func FromNetIP(ip net.IP) (result IP) {
if len(ip) == 16 {
copy(result[:], ip[:])
} else {
result[10] = 0xff
result[11] = 0xff
copy(result[12:], ip[:])
}
return
}
// IPv4 returns the IP address representation of a.b.c.d
func IPv4(a, b, c, d byte) (result IP) {
copy(result[:12], v4InV6Prefix)
result[12] = a
result[13] = b
result[14] = c
result[15] = d
return
}
// ParseIP parses a string representation of an IP address into an IP.
// Unlike net.ParseIP, it returns an error instead of a zero value on failure,
// since the zero value of `IP` is a representation of a valid IP (::0, the
// IPv6 "unspecified address").
func ParseIP(ipstr string) (ip IP, err error) {
// TODO reimplement this without net.ParseIP
netip := net.ParseIP(ipstr)
if netip == nil {
err = ErrInvalidIPString
return
}
netip = netip.To16()
copy(ip[:], netip)
return
}
// String returns the string representation of an IP
func (ip IP) String() string {
// TODO reimplement this without using (net.IP).String()
return (net.IP)(ip[:]).String()
}
// IsIPv4 returns whether the IP is an IPv4 address.
func (ip IP) IsIPv4() bool {
return bytes.Equal(ip[:12], v4InV6Prefix)
}
// IsLoopback returns whether the IP is a loopback address.
func (ip IP) IsLoopback() bool {
if ip.IsIPv4() {
return ip[12] == 127
} else {
return ip == IPv6loopback
}
}
func (ip IP) IsUnspecified() bool {
return ip == IPv4zero || ip == IPv6zero
}
func rawCidrMask(length int) (m IP) {
n := uint(length)
for i := 0; i < 16; i++ {
if n >= 8 {
m[i] = 0xff
n -= 8
continue
}
m[i] = ^byte(0xff >> n)
return
}
return
}
func (ip IP) applyMask(mask IP) (result IP) {
for i := 0; i < 16; i += 1 {
result[i] = ip[i] & mask[i]
}
return
}
func cidrMask(ones, bits int) (result IP) {
switch bits {
case 32:
return rawCidrMask(96 + ones)
case 128:
return rawCidrMask(ones)
default:
return
}
}
// Mask returns the result of masking ip with the CIDR mask of
// length 'ones', out of a total of 'bits' (which must be either
// 32 for an IPv4 subnet or 128 for an IPv6 subnet).
func (ip IP) Mask(ones, bits int) (result IP) {
return ip.applyMask(cidrMask(ones, bits))
}
// ToNetIPNet converts an IPNet into a net.IPNet.
func (cidr IPNet) ToNetIPNet() (result net.IPNet) {
return net.IPNet{
IP: cidr.IP.NetIP(),
Mask: net.CIDRMask(int(cidr.PrefixLen), 128),
}
}
// Contains retuns whether the network contains `ip`.
func (cidr IPNet) Contains(ip IP) bool {
maskedIP := ip.Mask(int(cidr.PrefixLen), 128)
return cidr.IP == maskedIP
}
// FromNetIPnet converts a net.IPNet into an IPNet.
func FromNetIPNet(network net.IPNet) (result IPNet) {
ones, _ := network.Mask.Size()
if len(network.IP) == 16 {
copy(result.IP[:], network.IP[:])
} else {
result.IP[10] = 0xff
result.IP[11] = 0xff
copy(result.IP[12:], network.IP[:])
ones += 96
}
// perform masking so that equal CIDRs are ==
result.IP = result.IP.Mask(ones, 128)
result.PrefixLen = uint8(ones)
return
}
// String returns a string representation of an IPNet.
func (cidr IPNet) String() string {
ip := make(net.IP, 16)
copy(ip[:], cidr.IP[:])
ipnet := net.IPNet{
IP: ip,
Mask: net.CIDRMask(int(cidr.PrefixLen), 128),
}
return ipnet.String()
}
// IsZero tests whether ipnet is the zero value of an IPNet, 0::0/0.
// Although this is a valid subnet, it can still be used as a sentinel
// value in some contexts.
func (ipnet IPNet) IsZero() bool {
return ipnet == IPNet{}
}
// ParseCIDR parses a string representation of an IP network in CIDR notation,
// then returns it as an IPNet (along with the original, unmasked address).
func ParseCIDR(netstr string) (ip IP, ipnet IPNet, err error) {
// TODO reimplement this without net.ParseCIDR
nip, nipnet, err := net.ParseCIDR(netstr)
if err != nil {
return
}
return FromNetIP(nip), FromNetIPNet(*nipnet), nil
}

174
irc/flatip/flatip_test.go Normal file
View File

@ -0,0 +1,174 @@
package flatip
import (
"bytes"
"math/rand"
"net"
"testing"
"time"
)
func easyParseIP(ipstr string) (result net.IP) {
result = net.ParseIP(ipstr)
if result == nil {
panic(ipstr)
}
return
}
func easyParseFlat(ipstr string) (result IP) {
x := easyParseIP(ipstr)
return FromNetIP(x)
}
func easyParseIPNet(nipstr string) (result net.IPNet) {
_, nip, err := net.ParseCIDR(nipstr)
if err != nil {
panic(err)
}
return *nip
}
func TestBasic(t *testing.T) {
nip := easyParseIP("8.8.8.8")
flatip := FromNetIP(nip)
if flatip.String() != "8.8.8.8" {
t.Errorf("conversions don't work")
}
}
func TestLoopback(t *testing.T) {
localhost_v4 := easyParseFlat("127.0.0.1")
localhost_v4_again := easyParseFlat("127.2.3.4")
google := easyParseFlat("8.8.8.8")
loopback_v6 := easyParseFlat("::1")
google_v6 := easyParseFlat("2607:f8b0:4006:801::2004")
if !(localhost_v4.IsLoopback() && localhost_v4_again.IsLoopback() && loopback_v6.IsLoopback()) {
t.Errorf("can't detect loopbacks")
}
if google_v6.IsLoopback() || google.IsLoopback() {
t.Errorf("incorrectly detected loopbacks")
}
}
func TestContains(t *testing.T) {
nipnet := easyParseIPNet("8.8.0.0/16")
flatipnet := FromNetIPNet(nipnet)
nip := easyParseIP("8.8.8.8")
flatip_ := FromNetIP(nip)
if !flatipnet.Contains(flatip_) {
t.Errorf("contains doesn't work")
}
}
var testIPStrs = []string{
"8.8.8.8",
"127.0.0.1",
"1.1.1.1",
"128.127.65.64",
"2001:0db8::1",
"::1",
"255.255.255.255",
}
func doMaskingTest(ip net.IP, t *testing.T) {
flat := FromNetIP(ip)
netLen := len(ip) * 8
for i := 0; i < netLen; i++ {
masked := flat.Mask(i, netLen)
netMask := net.CIDRMask(i, netLen)
netMasked := ip.Mask(netMask)
if !bytes.Equal(masked[:], netMasked.To16()) {
t.Errorf("Masking %s with %d/%d; expected %s, got %s", ip.String(), i, netLen, netMasked.String(), masked.String())
}
}
}
func TestMasking(t *testing.T) {
for _, ipstr := range testIPStrs {
doMaskingTest(easyParseIP(ipstr), t)
}
}
func TestMaskingFuzz(t *testing.T) {
r := rand.New(rand.NewSource(time.Now().UnixNano()))
buf := make([]byte, 4)
for i := 0; i < 10000; i++ {
r.Read(buf)
doMaskingTest(net.IP(buf), t)
}
buf = make([]byte, 16)
for i := 0; i < 10000; i++ {
r.Read(buf)
doMaskingTest(net.IP(buf), t)
}
}
func BenchmarkMasking(b *testing.B) {
ip := easyParseIP("2001:0db8::42")
flat := FromNetIP(ip)
b.ResetTimer()
for i := 0; i < b.N; i++ {
flat.Mask(64, 128)
}
}
func BenchmarkMaskingLegacy(b *testing.B) {
ip := easyParseIP("2001:0db8::42")
mask := net.CIDRMask(64, 128)
b.ResetTimer()
for i := 0; i < b.N; i++ {
ip.Mask(mask)
}
}
func BenchmarkMaskingCached(b *testing.B) {
i := easyParseIP("2001:0db8::42")
flat := FromNetIP(i)
mask := cidrMask(64, 128)
b.ResetTimer()
for i := 0; i < b.N; i++ {
flat.applyMask(mask)
}
}
func BenchmarkMaskingConstruct(b *testing.B) {
for i := 0; i < b.N; i++ {
cidrMask(69, 128)
}
}
func BenchmarkContains(b *testing.B) {
ip := easyParseIP("2001:0db8::42")
flat := FromNetIP(ip)
_, ipnet, err := net.ParseCIDR("2001:0db8::/64")
if err != nil {
panic(err)
}
flatnet := FromNetIPNet(*ipnet)
b.ResetTimer()
for i := 0; i < b.N; i++ {
flatnet.Contains(flat)
}
}
func BenchmarkContainsLegacy(b *testing.B) {
ip := easyParseIP("2001:0db8::42")
_, ipnetptr, err := net.ParseCIDR("2001:0db8::/64")
if err != nil {
panic(err)
}
ipnet := *ipnetptr
b.ResetTimer()
for i := 0; i < b.N; i++ {
ipnet.Contains(ip)
}
}

3
irc/gateways.go
View File

@ -9,6 +9,7 @@ import (
"errors"
"net"
"github.com/oragono/oragono/irc/flatip"
"github.com/oragono/oragono/irc/modes"
"github.com/oragono/oragono/irc/utils"
)
@ -87,7 +88,7 @@ func (client *Client) ApplyProxiedIP(session *Session, proxiedIP net.IP, tls boo
}
// successfully added a limiter entry for the proxied IP;
// remove the entry for the real IP if applicable (#197)
client.server.connectionLimiter.RemoveClient(session.realIP)
client.server.connectionLimiter.RemoveClient(flatip.FromNetIP(session.realIP))
// given IP is sane! override the client's current IP
client.server.logger.Info("connect-ip", "Accepted proxy IP for client", proxiedIP.String())

6
irc/handlers.go
View File

@ -24,6 +24,7 @@ import (
"github.com/goshuirc/irc-go/ircmsg"
"github.com/oragono/oragono/irc/caps"
"github.com/oragono/oragono/irc/custime"
"github.com/oragono/oragono/irc/flatip"
"github.com/oragono/oragono/irc/history"
"github.com/oragono/oragono/irc/jwt"
"github.com/oragono/oragono/irc/modes"
@ -2798,6 +2799,11 @@ func unDLineHandler(server *Server, client *Client, msg ircmsg.IrcMessage, rb *R
// get host
hostString := msg.Params[0]
// TODO(#1447) consolidate this into the "unban" command
if flatip, ipErr := flatip.ParseIP(hostString); ipErr == nil {
server.connectionLimiter.ResetThrottle(flatip)
}
// check host
hostNet, err := utils.NormalizedNetFromString(hostString)

25
irc/server.go
View File

@ -23,6 +23,7 @@ import (
"github.com/oragono/oragono/irc/caps"
"github.com/oragono/oragono/irc/connection_limits"
"github.com/oragono/oragono/irc/flatip"
"github.com/oragono/oragono/irc/history"
"github.com/oragono/oragono/irc/logger"
"github.com/oragono/oragono/irc/modes"
@ -160,31 +161,23 @@ func (server *Server) checkBans(config *Config, ipaddr net.IP, checkScripts bool
}
}
flat := flatip.FromNetIP(ipaddr)
// check DLINEs
isBanned, info := server.dlines.CheckIP(ipaddr)
isBanned, info := server.dlines.CheckIP(flat)
if isBanned {
server.logger.Info("connect-ip", fmt.Sprintf("Client from %v rejected by d-line", ipaddr))
server.logger.Info("connect-ip", "Client rejected by d-line", ipaddr.String())
return true, false, info.BanMessage("You are banned from this server (%s)")
}
// check connection limits
err := server.connectionLimiter.AddClient(ipaddr)
err := server.connectionLimiter.AddClient(flat)
if err == connection_limits.ErrLimitExceeded {
// too many connections from one client, tell the client and close the connection
server.logger.Info("connect-ip", fmt.Sprintf("Client from %v rejected for connection limit", ipaddr))
server.logger.Info("connect-ip", "Client rejected for connection limit", ipaddr.String())
return true, false, "Too many clients from your network"
} else if err == connection_limits.ErrThrottleExceeded {
duration := config.Server.IPLimits.BanDuration
if duration != 0 {
server.dlines.AddIP(ipaddr, duration, throttleMessage,
"Exceeded automated connection throttle", "auto.connection.throttler")
// 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.connectionLimiter.ResetThrottle(ipaddr)
}
server.logger.Info(
"connect-ip",
fmt.Sprintf("Client from %v exceeded connection throttle, d-lining for %v", ipaddr, duration))
server.logger.Info("connect-ip", "Client exceeded connection throttle", ipaddr.String())
return true, false, throttleMessage
} else if err != nil {
server.logger.Warning("internal", "unexpected ban result", err.Error())
@ -211,7 +204,7 @@ func (server *Server) checkBans(config *Config, ipaddr net.IP, checkScripts bool
}
if output.Result == IPBanned {
// XXX roll back IP connection/throttling addition for the IP
server.connectionLimiter.RemoveClient(ipaddr)
server.connectionLimiter.RemoveClient(flat)
server.logger.Info("connect-ip", "Rejected client due to ip-check-script", ipaddr.String())
return true, false, output.BanMessage
} else if output.Result == IPRequireSASL {

3
traditional.yaml
View File

@ -220,9 +220,6 @@ server:
window: 10m
# maximum number of new connections per IP/CIDR within the given duration
max-connections-per-window: 32
# how long to ban offenders for. after banning them, the number of connections is
# reset, which lets you use /UNDLINE to unban people
throttle-ban-duration: 10m
# how wide the CIDR should be for IPv4 (a /32 is a fully specified IPv4 address)
cidr-len-ipv4: 32