"crypto/subtle"
"encoding/binary"
"io"
- "log"
"sync"
"sync/atomic"
"time"
"chacha20"
+ "github.com/Sirupsen/logrus"
+ "github.com/pkg/errors"
"golang.org/x/crypto/blake2b"
"golang.org/x/crypto/poly1305"
)
const (
+ // NonceSize is nonce size
NonceSize = 8
- NonceBucketSize = 256
- TagSize = poly1305.TagSize
- // S20BS is ChaCha20's internal blocksize in bytes
- S20BS = 64
- // Maximal amount of bytes transfered with single key (4 GiB)
+ nonceBucketSize = 256
+ tagSize = poly1305.TagSize
+ CC20IBS = 64
+ // MaxBytesPerKey is maximal amount of bytes transferred with single key (4 GiB)
MaxBytesPerKey uint64 = 1 << 32
// Heartbeat rate, relative to Timeout
- TimeoutHeartbeat = 4
- // Minimal valid packet length
+ timeoutHeartbeat = 4
+ // MinPktLength is minimal valid packet length
MinPktLength = 1 + 16 + 8
- // Padding byte
- PadByte = byte(0x80)
+ // padding byte
+ padByte = byte(0x80)
+
+ logPrefixPeer = "peer_"
)
-func newNonces(key *[32]byte, i uint64) chan *[NonceSize]byte {
+func newNonces(key *[32]byte, i uint64) (chan *[NonceSize]byte, error) {
macKey := make([]byte, 32)
chacha20.XORKeyStream(macKey, make([]byte, 32), new([16]byte), key)
mac, err := blake2b.New256(macKey)
panic(err)
}
sum := make([]byte, mac.Size())
- nonces := make(chan *[NonceSize]byte, NonceBucketSize*3)
+ nonces := make(chan *[NonceSize]byte, nonceBucketSize*3)
go func() {
for {
buf := new([NonceSize]byte)
i += 2
}
}()
- return nonces
+ return nonces, nil
}
+// Peer is a GoVPN peer (client)
type Peer struct {
// Statistics (they are at the beginning for correct int64 alignment)
BytesIn uint64
HeartbeatSent uint64
// Basic
- Addr string
- ID *PeerID
- Conn io.Writer `json:"-"`
+ Addr string
+ ID *PeerID
+ Conn io.Writer `json:"-"`
+ Protocol Protocol
// Traffic behaviour
NoiseEnable bool
// Receiver
BusyR sync.Mutex `json:"-"`
bufR []byte
- tagR *[TagSize]byte
+ tagR *[tagSize]byte
keyAuthR *[SSize]byte
nonceR *[16]byte
pktSizeR int
// Transmitter
BusyT sync.Mutex `json:"-"`
bufT []byte
- tagT *[TagSize]byte
+ tagT *[tagSize]byte
keyAuthT *[SSize]byte
nonceT *[16]byte
frameT []byte
noncesT chan *[NonceSize]byte
}
+// LogFields returns a logrus compatible Fields to identity a single
+// peer in logs
+func (p *Peer) LogFields() logrus.Fields {
+ return logrus.Fields{
+ logPrefixPeer + "addr": p.Addr,
+ logPrefixPeer + "id": p.ID.String(),
+ logPrefixPeer + "established": p.Established.String(),
+ logPrefixPeer + "last_ping": p.LastPing.String(),
+ }
+}
+
+// ConfigurationLogFields returns a logrus compatible Fields with the
+// settings of a single peer. Complement LogFields() for extra debugging
+// details.
+func (p *Peer) ConfigurationLogFields() logrus.Fields {
+ return logrus.Fields{
+ logPrefixPeer + "timeout": p.Timeout.String(),
+ logPrefixPeer + "protocol": p.Protocol.String(),
+ logPrefixPeer + "noise": p.NoiseEnable,
+ logPrefixPeer + "cpr": p.CPR,
+ logPrefixPeer + "mtu": p.MTU,
+ logPrefixPeer + "encless": p.Encless,
+ }
+}
+
func (p *Peer) String() string {
return p.ID.String() + ":" + p.Addr
}
return time.Second / time.Duration(rate)
}
-func newPeer(isClient bool, addr string, conn io.Writer, conf *PeerConf, key *[SSize]byte) *Peer {
+func newPeer(isClient bool, addr string, conn io.Writer, conf *PeerConf, key *[SSize]byte) (*Peer, error) {
now := time.Now()
timeout := conf.Timeout
noiseEnable = true
timeout = cprCycle
} else {
- timeout = timeout / TimeoutHeartbeat
+ timeout = timeout / timeoutHeartbeat
}
- bufSize := S20BS + 2*conf.MTU
+ bufSize := CC20IBS + 2*conf.MTU
if conf.Encless {
bufSize += EnclessEnlargeSize
noiseEnable = true
bufR: make([]byte, bufSize),
bufT: make([]byte, bufSize),
- tagR: new([TagSize]byte),
- tagT: new([TagSize]byte),
+ tagR: new([tagSize]byte),
+ tagT: new([tagSize]byte),
keyAuthR: new([SSize]byte),
nonceR: new([16]byte),
keyAuthT: new([SSize]byte),
nonceT: new([16]byte),
}
+ var err error
if isClient {
- peer.noncesT = newNonces(peer.key, 1+2)
- peer.noncesR = newNonces(peer.key, 0+2)
- peer.noncesExpect = newNonces(peer.key, 0+2)
+ if peer.noncesT, err = newNonces(peer.key, 1+2); err != nil {
+ return nil, err
+ }
+ if peer.noncesR, err = newNonces(peer.key, 0+2); err != nil {
+ return nil, err
+ }
+ if peer.noncesExpect, err = newNonces(peer.key, 0+2); err != nil {
+ return nil, err
+ }
} else {
- peer.noncesT = newNonces(peer.key, 0+2)
- peer.noncesR = newNonces(peer.key, 1+2)
- peer.noncesExpect = newNonces(peer.key, 1+2)
+ if peer.noncesT, err = newNonces(peer.key, 0+2); err != nil {
+ return nil, err
+ }
+ if peer.noncesR, err = newNonces(peer.key, 1+2); err != nil {
+ return nil, err
+ }
+ if peer.noncesExpect, err = newNonces(peer.key, 1+2); err != nil {
+ return nil, err
+ }
}
peer.NonceExpect = make([]byte, NonceSize)
copy(peer.NonceExpect, nonce[:])
var i int
- peer.nonceBucketL = make(map[[NonceSize]byte]struct{}, NonceBucketSize)
- for i = 0; i < NonceBucketSize; i++ {
+ peer.nonceBucketL = make(map[[NonceSize]byte]struct{}, nonceBucketSize)
+ for i = 0; i < nonceBucketSize; i++ {
nonce = <-peer.noncesR
peer.nonceBucketL[*nonce] = struct{}{}
}
- peer.nonceBucketM = make(map[[NonceSize]byte]struct{}, NonceBucketSize)
- for i = 0; i < NonceBucketSize; i++ {
+ peer.nonceBucketM = make(map[[NonceSize]byte]struct{}, nonceBucketSize)
+ for i = 0; i < nonceBucketSize; i++ {
nonce = <-peer.noncesR
peer.nonceBucketM[*nonce] = struct{}{}
}
- peer.nonceBucketH = make(map[[NonceSize]byte]struct{}, NonceBucketSize)
- for i = 0; i < NonceBucketSize; i++ {
+ peer.nonceBucketH = make(map[[NonceSize]byte]struct{}, nonceBucketSize)
+ for i = 0; i < nonceBucketSize; i++ {
nonce = <-peer.noncesR
peer.nonceBucketH[*nonce] = struct{}{}
}
- return &peer
+ return &peer, nil
}
-// Process incoming Ethernet packet.
+// EthProcess processes incoming Ethernet packet.
// ready channel is TAPListen's synchronization channel used to tell him
// that he is free to receive new packets. Encrypted and authenticated
// packets will be sent to remote Peer side immediately.
-func (p *Peer) EthProcess(data []byte) {
- if len(data) > p.MTU-1 { // 1 is for padding byte
- log.Println("Padded data packet size", len(data)+1, "is bigger than MTU", p.MTU, p)
- return
+func (p *Peer) EthProcess(data []byte) error {
+ const paddingSize = 1
+ if len(data) > p.MTU-paddingSize {
+ logger.WithFields(
+ p.LogFields(),
+ ).WithFields(
+ p.ConfigurationLogFields(),
+ ).WithFields(
+ logrus.Fields{
+ "func": logFuncPrefix + "Peer.EthProcess",
+ "padding": paddingSize,
+ "packet_size": len(data),
+ },
+ ).Warning("Ignore padded data packet larger than MTU")
+ return nil
}
p.BusyT.Lock()
+ defer p.BusyT.Unlock()
// Zero size is a heartbeat packet
SliceZero(p.bufT)
if len(data) == 0 {
- p.bufT[S20BS+0] = PadByte
+ p.bufT[CC20IBS+0] = padByte
p.HeartbeatSent++
} else {
// Copy payload to our internal buffer and we are ready to
// accept the next one
- copy(p.bufT[S20BS:], data)
- p.bufT[S20BS+len(data)] = PadByte
+ copy(p.bufT[CC20IBS:], data)
+ p.bufT[CC20IBS+len(data)] = padByte
p.BytesPayloadOut += uint64(len(data))
}
if p.NoiseEnable && !p.Encless {
- p.frameT = p.bufT[S20BS : S20BS+p.MTU-TagSize]
+ p.frameT = p.bufT[CC20IBS : CC20IBS+p.MTU-tagSize]
} else if p.Encless {
- p.frameT = p.bufT[S20BS : S20BS+p.MTU]
+ p.frameT = p.bufT[CC20IBS : CC20IBS+p.MTU]
} else {
- p.frameT = p.bufT[S20BS : S20BS+len(data)+1+NonceSize]
+ p.frameT = p.bufT[CC20IBS : CC20IBS+len(data)+1+NonceSize]
}
copy(p.frameT[len(p.frameT)-NonceSize:], (<-p.noncesT)[:])
var out []byte
var err error
out, err = EnclessEncode(p.key, p.nonceT, p.frameT[:len(p.frameT)-NonceSize])
if err != nil {
- panic(err)
+ return errors.Wrap(err, wrapEnclessEncode)
}
out = append(out, p.frameT[len(p.frameT)-NonceSize:]...)
} else {
chacha20.XORKeyStream(
- p.bufT[:S20BS+len(p.frameT)-NonceSize],
- p.bufT[:S20BS+len(p.frameT)-NonceSize],
+ p.bufT[:CC20IBS+len(p.frameT)-NonceSize],
+ p.bufT[:CC20IBS+len(p.frameT)-NonceSize],
p.nonceT,
p.key,
)
copy(p.keyAuthT[:], p.bufT[:SSize])
poly1305.Sum(p.tagT, p.frameT, p.keyAuthT)
- atomic.AddUint64(&p.BytesOut, uint64(len(p.frameT)+TagSize))
+ atomic.AddUint64(&p.BytesOut, uint64(len(p.frameT)+tagSize))
out = append(p.tagT[:], p.frameT...)
}
p.FramesOut++
- p.Conn.Write(out)
- p.BusyT.Unlock()
+ _, err := p.Conn.Write(out)
+ return errors.Wrap(err, "p.Conn.Write")
}
+// PktProcess processes data of a single packet
func (p *Peer) PktProcess(data []byte, tap io.Writer, reorderable bool) bool {
+ fields := logrus.Fields{
+ "func": logFuncPrefix + "Peer.PktProcess",
+ "reorderable": reorderable,
+ "data": len(data),
+ }
if len(data) < MinPktLength {
+ logger.WithFields(
+ p.LogFields(),
+ ).WithFields(
+ fields,
+ ).WithField(
+ "minimum_packet_Length",
+ MinPktLength,
+ ).Debug("Ignore packet smaller than allowed minimum")
return false
}
- if !p.Encless && len(data) > len(p.bufR)-S20BS {
+ if !p.Encless && len(data) > len(p.bufR)-CC20IBS {
return false
}
var out []byte
+ var err error
p.BusyR.Lock()
+ defer p.BusyR.Unlock()
copy(p.nonceR[8:], data[len(data)-NonceSize:])
if p.Encless {
- var err error
out, err = EnclessDecode(p.key, p.nonceR, data[:len(data)-NonceSize])
if err != nil {
+ logger.WithFields(
+ p.LogFields(),
+ ).WithError(err).Debug("Failed to decode encless")
p.FramesUnauth++
- p.BusyR.Unlock()
return false
}
} else {
for i := 0; i < SSize; i++ {
p.bufR[i] = 0
}
- copy(p.bufR[S20BS:], data[TagSize:])
+ copy(p.bufR[CC20IBS:], data[tagSize:])
chacha20.XORKeyStream(
- p.bufR[:S20BS+len(data)-TagSize-NonceSize],
- p.bufR[:S20BS+len(data)-TagSize-NonceSize],
+ p.bufR[:CC20IBS+len(data)-tagSize-NonceSize],
+ p.bufR[:CC20IBS+len(data)-tagSize-NonceSize],
p.nonceR,
p.key,
)
copy(p.keyAuthR[:], p.bufR[:SSize])
- copy(p.tagR[:], data[:TagSize])
- if !poly1305.Verify(p.tagR, data[TagSize:], p.keyAuthR) {
+ copy(p.tagR[:], data[:tagSize])
+ if !poly1305.Verify(p.tagR, data[tagSize:], p.keyAuthR) {
p.FramesUnauth++
- p.BusyR.Unlock()
return false
}
- out = p.bufR[S20BS : S20BS+len(data)-TagSize-NonceSize]
+ out = p.bufR[CC20IBS : CC20IBS+len(data)-tagSize-NonceSize]
}
if reorderable {
// or too new (many packets were lost)
if !(foundL || foundM || foundH) {
p.FramesDup++
- p.BusyR.Unlock()
return false
}
// Delete seen nonce
p.nonceBucketL, p.nonceBucketM = p.nonceBucketM, p.nonceBucketH
p.nonceBucketH = make(map[[NonceSize]byte]struct{})
var nonce *[NonceSize]byte
- for i := 0; i < NonceBucketSize; i++ {
+ for i := 0; i < nonceBucketSize; i++ {
nonce = <-p.noncesR
p.nonceBucketH[*nonce] = struct{}{}
}
} else {
if subtle.ConstantTimeCompare(data[len(data)-NonceSize:], p.NonceExpect) != 1 {
p.FramesDup++
- p.BusyR.Unlock()
return false
}
copy(p.NonceExpect, (<-p.noncesExpect)[:])
p.FramesIn++
atomic.AddUint64(&p.BytesIn, uint64(len(data)))
p.LastPing = time.Now()
- p.pktSizeR = bytes.LastIndexByte(out, PadByte)
+ p.pktSizeR = bytes.LastIndexByte(out, padByte)
if p.pktSizeR == -1 {
- p.BusyR.Unlock()
return false
}
// Validate the pad
for i := p.pktSizeR + 1; i < len(out); i++ {
if out[i] != 0 {
- p.BusyR.Unlock()
return false
}
}
if p.pktSizeR == 0 {
p.HeartbeatRecv++
- p.BusyR.Unlock()
return true
}
p.BytesPayloadIn += uint64(p.pktSizeR)
- tap.Write(out[:p.pktSizeR])
- p.BusyR.Unlock()
+ if _, err = tap.Write(out[:p.pktSizeR]); err != nil {
+ logger.WithFields(p.LogFields()).WithFields(fields).WithError(err).Error("Can't write to TAP")
+ }
return true
}
+// PeerTapProcessor processes a TUN/TAP peer
func PeerTapProcessor(peer *Peer, tap *TAP, terminator chan struct{}) {
var data []byte
var now time.Time
+ var err error
+ fields := logrus.Fields{
+ "func": logFuncPrefix + "PeerTapProcessor",
+ "tap": tap.Name,
+ }
lastSent := time.Now()
heartbeat := time.NewTicker(peer.Timeout)
if peer.CPRCycle == time.Duration(0) {
case <-heartbeat.C:
now = time.Now()
if lastSent.Add(peer.Timeout).Before(now) {
- peer.EthProcess(nil)
+ if err = peer.EthProcess(nil); err != nil {
+ logger.WithFields(
+ fields,
+ ).WithFields(
+ peer.LogFields(),
+ ).WithError(err).Warn(
+ "Can't process nil ethernet packet",
+ )
+ }
lastSent = now
}
case data = <-tap.Sink:
- peer.EthProcess(data)
+ if err = peer.EthProcess(data); err != nil {
+ logger.WithFields(
+ fields,
+ ).WithFields(
+ peer.LogFields(),
+ ).WithError(err).Warn("Can't process ethernet packet")
+ }
lastSent = time.Now()
}
}
case <-terminator:
break CPRProcessor
case data = <-tap.Sink:
- peer.EthProcess(data)
+ if err = peer.EthProcess(data); err != nil {
+ logger.WithFields(
+ fields,
+ ).WithFields(
+ peer.LogFields(),
+ ).WithError(err).Warn("Can't process ethernet packet")
+ }
default:
}
if data == nil {
- peer.EthProcess(nil)
+ if err = peer.EthProcess(nil); err != nil {
+ logger.WithFields(
+ fields,
+ ).WithFields(
+ peer.LogFields(),
+ ).WithError(err).Warn("Can't process nil ethernet packet")
+ }
}
time.Sleep(peer.CPRCycle)
}