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3 Commits

Author SHA1 Message Date
426bd5a659
lower time limit for upstream resolver 2024-06-06 07:44:26 +03:00
5ff8521bf4
update deps 2024-06-06 07:44:26 +03:00
0faa8ec86a
rework address mapping 2024-06-06 07:44:26 +03:00
7 changed files with 164 additions and 57 deletions

View File

@ -1,43 +1,148 @@
package main
import (
"crypto/rand"
"encoding/binary"
"log"
"math"
"net"
"sync"
"time"
"github.com/cespare/xxhash/v2"
)
// TODO: write more convenient version
func addrMap(srcIp net.IP, dstCidr *net.IPNet) net.IP {
const (
addrMapHouseKeepInterval = time.Second / 2
)
var (
addr4, addr6 sync.Map
)
type AddrMap struct {
SrcAddr net.IP
DstAddr net.IP
Ttl uint32
Created time.Time
}
func (a *AddrMap) GetTtl() int32 {
x := math.Trunc(time.Since(a.Created).Round(addrMapHouseKeepInterval).Seconds())
return int32(a.Ttl) - int32(x)
}
func setupAddrMapHousekeeping() {
go func() {
for {
time.Sleep(addrMapHouseKeepInterval)
addr4.Range(func(key, value any) bool {
a, ok := value.(AddrMap)
if ok {
if a.GetTtl() > 1 {
return true
}
}
// delete if value is bogus or if ttl is less than second
addr4.Delete(key)
return true
})
}
}()
go func() {
for {
time.Sleep(addrMapHouseKeepInterval)
addr6.Range(func(key, value any) bool {
a, ok := value.(AddrMap)
if ok {
if a.GetTtl() > 1 {
return true
}
}
// delete if value is bogus or if ttl is less than second
addr6.Delete(key)
return true
})
}
}()
}
func addrMapGet(srcIp net.IP, dstCidr *net.IPNet, ttl uint32) net.IP {
addrlen := len(srcIp)
switch addrlen {
case net.IPv4len, net.IPv6len:
default:
log.Fatalf("addrMapGet(): src size mismatch: %v", addrlen)
}
if addrlen != len(dstCidr.IP) {
log.Fatalf("addrMap(): src/dst size mismatch: %v vs %v", len(srcIp), len(dstCidr.IP))
log.Fatalf("addrMapGet(): src/dst size mismatch: %v vs %v", addrlen, len(dstCidr.IP))
}
if addrlen != len(dstCidr.Mask) {
log.Fatalf("addrMapGet(): src/dst size mismatch: %v vs %v", addrlen, len(dstCidr.IP))
}
var addr net.IP = make([]byte, addrlen)
var curr AddrMap
curr.SrcAddr = make([]byte, addrlen)
curr.DstAddr = make([]byte, addrlen)
copy(curr.DstAddr, srcIp)
curr.Ttl = ttl
hsum := xxhash.Sum64(srcIp)
bsum := binary.NativeEndian.AppendUint64([]byte{}, hsum)
blen := len(bsum)
if addrlen > blen {
// extend bsum
tmp := append(make([]byte, addrlen-blen), bsum...)
bsum = tmp
}
if addrlen < blen {
// trim bsum
bsum = bsum[:addrlen]
for {
_, err := rand.Read(curr.SrcAddr)
if err != nil {
log.Fatalf("rand.Read(): error %v", err)
}
// apply inverted mask to bsum and sum with addr
// adjust random bytes to dstCidr
for i := range addrlen / 4 {
a := binary.NativeEndian.Uint32(dstCidr.IP[i*4:])
b := binary.NativeEndian.Uint32(bsum[i*4:])
b := binary.NativeEndian.Uint32(curr.SrcAddr[i*4:])
m := binary.NativeEndian.Uint32(dstCidr.Mask[i*4:])
a += (b & ^m)
binary.NativeEndian.PutUint32(addr[i*4:], a)
binary.NativeEndian.PutUint32(curr.SrcAddr[i*4:], a)
}
hsum := xxhash.Sum64(curr.SrcAddr)
curr.Created = time.Now()
var xprev any
var loaded bool
switch addrlen {
case net.IPv4len:
xprev, loaded = addr4.LoadOrStore(hsum, curr)
case net.IPv6len:
xprev, loaded = addr6.LoadOrStore(hsum, curr)
}
if !loaded {
// early return
return curr.SrcAddr
}
return addr
prev, ok := xprev.(AddrMap)
if !ok {
log.Fatalf("addrMapGet(): wrong value type from sync.Map")
}
if !net.IP.Equal(curr.SrcAddr, prev.SrcAddr) {
// generate next random address
continue
}
if !net.IP.Equal(curr.DstAddr, prev.DstAddr) {
// generate next random address
continue
}
if prev.GetTtl() < int32(curr.Ttl) {
switch addrlen {
case net.IPv4len:
addr4.Store(hsum, curr)
case net.IPv6len:
addr6.Store(hsum, curr)
}
}
break
}
return curr.SrcAddr
}

6
cfg.go
View File

@ -14,14 +14,14 @@ const (
cfgResolverEndpoint = "127.1.0.1:53"
cfgResolverProto = "tcp"
cfgResolverTimeout = 2500 * time.Millisecond
cfgResolverTimeout = 2000 * time.Millisecond
cfgNftTable = "uni"
cfgNftTableFamily = nft.TableFamilyINet
cfgNftMapV4 = "tele4"
cfgNftMapV6 = "tele6"
cfgNftCidrV4 = "251.0.0.0/8"
cfgNftCidrV6 = "2001:db8:11::/48"
cfgNftCidrV4 = "198.18.0.0/15"
cfgNftCidrV6 = "2001:db8:11::/80"
cfgSoaNs = "gw.vpn."
cfgSoaMbox = "dns.gw.vpn."

View File

@ -140,18 +140,19 @@ func dnsRemap(qname string, qtype uint16, orig *dns.Msg) ([]PowerDnsAnswer, erro
continue
}
// HACK: clip ttl
r.Ttl = dnsClipTtl(r.Ttl)
var srcAddr net.IP = make([]byte, r.AddrLen)
copy(srcAddr, r.Addr)
var dstAddr net.IP
switch r.AddrLen {
case net.IPv4len:
dstAddr = addrMap(r.Addr, nftCidrV4)
dstAddr = addrMapGet(r.Addr, nftCidrV4, r.Ttl)
case net.IPv6len:
dstAddr = addrMap(r.Addr, nftCidrV6)
dstAddr = addrMapGet(r.Addr, nftCidrV6, r.Ttl)
}
// HACK: clip ttl
r.Ttl = dnsClipTtl(r.Ttl)
// HACK: replace addr
copy(r.Addr, dstAddr)

View File

@ -1,7 +1,7 @@
#!/usr/sbin/nft -f
define n_tele4 = 251.0.0.0/8
define n_tele6 = 2001:db8:11::/48
define n_tele4 = 198.18.0.0/15
define n_tele6 = 2001:db8:11::/80
table inet uni {

12
go.mod
View File

@ -40,13 +40,13 @@ require (
github.com/twitchyliquid64/golang-asm v0.15.1 // indirect
github.com/ugorji/go/codec v1.2.12 // indirect
golang.org/x/arch v0.8.0 // indirect
golang.org/x/crypto v0.23.0 // indirect
golang.org/x/mod v0.17.0 // indirect
golang.org/x/net v0.25.0 // indirect
golang.org/x/crypto v0.24.0 // indirect
golang.org/x/mod v0.18.0 // indirect
golang.org/x/net v0.26.0 // indirect
golang.org/x/sync v0.7.0 // indirect
golang.org/x/sys v0.20.0 // indirect
golang.org/x/text v0.15.0 // indirect
golang.org/x/tools v0.21.0 // indirect
golang.org/x/sys v0.21.0 // indirect
golang.org/x/text v0.16.0 // indirect
golang.org/x/tools v0.22.0 // indirect
google.golang.org/protobuf v1.34.1 // indirect
gopkg.in/yaml.v3 v3.0.1 // indirect
)

24
go.sum
View File

@ -97,22 +97,22 @@ github.com/vishvananda/netns v0.0.0-20180720170159-13995c7128cc/go.mod h1:ZjcWmF
golang.org/x/arch v0.0.0-20210923205945-b76863e36670/go.mod h1:5om86z9Hs0C8fWVUuoMHwpExlXzs5Tkyp9hOrfG7pp8=
golang.org/x/arch v0.8.0 h1:3wRIsP3pM4yUptoR96otTUOXI367OS0+c9eeRi9doIc=
golang.org/x/arch v0.8.0/go.mod h1:FEVrYAQjsQXMVJ1nsMoVVXPZg6p2JE2mx8psSWTDQys=
golang.org/x/crypto v0.23.0 h1:dIJU/v2J8Mdglj/8rJ6UUOM3Zc9zLZxVZwwxMooUSAI=
golang.org/x/crypto v0.23.0/go.mod h1:CKFgDieR+mRhux2Lsu27y0fO304Db0wZe70UKqHu0v8=
golang.org/x/mod v0.17.0 h1:zY54UmvipHiNd+pm+m0x9KhZ9hl1/7QNMyxXbc6ICqA=
golang.org/x/mod v0.17.0/go.mod h1:hTbmBsO62+eylJbnUtE2MGJUyE7QWk4xUqPFrRgJ+7c=
golang.org/x/net v0.25.0 h1:d/OCCoBEUq33pjydKrGQhw7IlUPI2Oylr+8qLx49kac=
golang.org/x/net v0.25.0/go.mod h1:JkAGAh7GEvH74S6FOH42FLoXpXbE/aqXSrIQjXgsiwM=
golang.org/x/crypto v0.24.0 h1:mnl8DM0o513X8fdIkmyFE/5hTYxbwYOjDS/+rK6qpRI=
golang.org/x/crypto v0.24.0/go.mod h1:Z1PMYSOR5nyMcyAVAIQSKCDwalqy85Aqn1x3Ws4L5DM=
golang.org/x/mod v0.18.0 h1:5+9lSbEzPSdWkH32vYPBwEpX8KwDbM52Ud9xBUvNlb0=
golang.org/x/mod v0.18.0/go.mod h1:hTbmBsO62+eylJbnUtE2MGJUyE7QWk4xUqPFrRgJ+7c=
golang.org/x/net v0.26.0 h1:soB7SVo0PWrY4vPW/+ay0jKDNScG2X9wFeYlXIvJsOQ=
golang.org/x/net v0.26.0/go.mod h1:5YKkiSynbBIh3p6iOc/vibscux0x38BZDkn8sCUPxHE=
golang.org/x/sync v0.7.0 h1:YsImfSBoP9QPYL0xyKJPq0gcaJdG3rInoqxTWbfQu9M=
golang.org/x/sync v0.7.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
golang.org/x/sys v0.5.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
golang.org/x/sys v0.20.0 h1:Od9JTbYCk261bKm4M/mw7AklTlFYIa0bIp9BgSm1S8Y=
golang.org/x/sys v0.20.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
golang.org/x/text v0.15.0 h1:h1V/4gjBv8v9cjcR6+AR5+/cIYK5N/WAgiv4xlsEtAk=
golang.org/x/text v0.15.0/go.mod h1:18ZOQIKpY8NJVqYksKHtTdi31H5itFRjB5/qKTNYzSU=
golang.org/x/tools v0.21.0 h1:qc0xYgIbsSDt9EyWz05J5wfa7LOVW0YTLOXrqdLAWIw=
golang.org/x/tools v0.21.0/go.mod h1:aiJjzUbINMkxbQROHiO6hDPo2LHcIPhhQsa9DLh0yGk=
golang.org/x/sys v0.21.0 h1:rF+pYz3DAGSQAxAu1CbC7catZg4ebC4UIeIhKxBZvws=
golang.org/x/sys v0.21.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
golang.org/x/text v0.16.0 h1:a94ExnEXNtEwYLGJSIUxnWoxoRz/ZcCsV63ROupILh4=
golang.org/x/text v0.16.0/go.mod h1:GhwF1Be+LQoKShO3cGOHzqOgRrGaYc9AvblQOmPVHnI=
golang.org/x/tools v0.22.0 h1:gqSGLZqv+AI9lIQzniJ0nZDRG5GBPsSi+DRNHWNz6yA=
golang.org/x/tools v0.22.0/go.mod h1:aCwcsjqvq7Yqt6TNyX7QMU2enbQ/Gt0bo6krSeEri+c=
google.golang.org/protobuf v1.34.1 h1:9ddQBjfCyZPOHPUiPxpYESBLc+T8P3E+Vo4IbKZgFWg=
google.golang.org/protobuf v1.34.1/go.mod h1:c6P6GXX6sHbq/GpV6MGZEdwhWPcYBgnhAHhKbcUYpos=
gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=

View File

@ -25,6 +25,7 @@ func main() {
setupNftables()
r := setupGin()
setupAddrMapHousekeeping()
log.Printf("%s: ready\n", userAgent)
if err := r.Run(cfgListen); err != nil {