/
serversInfo.go
195 lines (178 loc) · 5.33 KB
/
serversInfo.go
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package main
import (
"encoding/hex"
"math/rand"
"net"
"strings"
"sync"
"time"
"github.com/VividCortex/ewma"
"github.com/jedisct1/dlog"
"golang.org/x/crypto/ed25519"
)
const (
RTTEwmaDecay = 10.0
DefaultPort = 443
)
type ServerInformalProperties uint64
const (
ServerInformalPropertyDNSSEC = ServerInformalProperties(1) << 0
ServerInformalPropertyNoLog = ServerInformalProperties(1) << 1
)
type RegisteredServer struct {
name string
stamp ServerStamp
}
type ServerInfo struct {
sync.RWMutex
MagicQuery [8]byte
ServerPk [32]byte
SharedKey [32]byte
CryptoConstruction CryptoConstruction
Name string
Timeout time.Duration
UDPAddr *net.UDPAddr
TCPAddr *net.TCPAddr
lastActionTS time.Time
rtt ewma.MovingAverage
initialRtt int
}
type ServersInfo struct {
sync.RWMutex
inner []ServerInfo
registeredServers []RegisteredServer
}
func (serversInfo *ServersInfo) registerServer(proxy *Proxy, name string, stamp ServerStamp) error {
newRegisteredServer := RegisteredServer{name: name, stamp: stamp}
serversInfo.Lock()
defer serversInfo.Unlock()
for i, oldRegisteredServer := range serversInfo.registeredServers {
if oldRegisteredServer.name == name {
serversInfo.registeredServers[i] = newRegisteredServer
return nil
}
}
serversInfo.registeredServers = append(serversInfo.registeredServers, newRegisteredServer)
return nil
}
func (serversInfo *ServersInfo) refreshServer(proxy *Proxy, name string, stamp ServerStamp) error {
serversInfo.Lock()
defer serversInfo.Unlock()
newServer, err := serversInfo.fetchServerInfo(proxy, name, stamp)
if err != nil {
return err
}
newServer.rtt = ewma.NewMovingAverage(RTTEwmaDecay)
for i, oldServer := range serversInfo.inner {
if oldServer.Name == newServer.Name {
serversInfo.inner[i] = newServer
return nil
}
}
serversInfo.inner = append(serversInfo.inner, newServer)
serversInfo.registeredServers = append(serversInfo.registeredServers, RegisteredServer{name: name, stamp: stamp})
return nil
}
func (serversInfo *ServersInfo) refresh(proxy *Proxy) (int, error) {
dlog.Infof("Refreshing certificates")
serversInfo.RLock()
registeredServers := serversInfo.registeredServers
serversInfo.RUnlock()
liveServers := 0
var err error
for _, registeredServer := range registeredServers {
if err = serversInfo.refreshServer(proxy, registeredServer.name, registeredServer.stamp); err == nil {
liveServers++
}
}
serversInfo.Lock()
inner := serversInfo.inner
innerLen := len(inner)
for i := 0; i < innerLen; i++ {
for j := i + 1; j < innerLen; j++ {
if inner[j].initialRtt < inner[i].initialRtt {
inner[j], inner[i] = inner[i], inner[j]
}
}
}
serversInfo.inner = inner
if innerLen > 1 {
dlog.Noticef("Server with the lowest initial latency: %s (rtt: %dms)", inner[0].Name, inner[0].initialRtt)
proxy.certIgnoreTimestamp = false
}
serversInfo.Unlock()
return liveServers, err
}
func (serversInfo *ServersInfo) liveServers() int {
serversInfo.RLock()
liveServers := len(serversInfo.inner)
serversInfo.RUnlock()
return liveServers
}
func (serversInfo *ServersInfo) getOne() *ServerInfo {
serversInfo.Lock()
defer serversInfo.Unlock()
serversCount := len(serversInfo.inner)
if serversCount <= 0 {
return nil
}
candidate := rand.Intn(serversCount)
if candidate == 0 {
return &serversInfo.inner[candidate]
}
if serversInfo.inner[candidate].rtt.Value() < serversInfo.inner[0].rtt.Value() {
serversInfo.inner[candidate], serversInfo.inner[0] = serversInfo.inner[0], serversInfo.inner[candidate]
}
candidate = rand.Intn(Max(Min(serversCount, 2), len(serversInfo.inner)))
serverInfo := &serversInfo.inner[candidate]
return serverInfo
}
func (serversInfo *ServersInfo) fetchServerInfo(proxy *Proxy, name string, stamp ServerStamp) (ServerInfo, error) {
serverPk, err := hex.DecodeString(strings.Replace(stamp.serverPkStr, ":", "", -1))
if err != nil || len(serverPk) != ed25519.PublicKeySize {
dlog.Fatalf("Unsupported public key: [%v]", serverPk)
}
certInfo, rtt, err := FetchCurrentCert(proxy, &name, proxy.mainProto, serverPk, stamp.serverAddrStr, stamp.providerName)
if err != nil {
return ServerInfo{}, err
}
remoteUDPAddr, err := net.ResolveUDPAddr("udp", stamp.serverAddrStr)
if err != nil {
return ServerInfo{}, err
}
remoteTCPAddr, err := net.ResolveTCPAddr("tcp", stamp.serverAddrStr)
if err != nil {
return ServerInfo{}, err
}
serverInfo := ServerInfo{
MagicQuery: certInfo.MagicQuery,
ServerPk: certInfo.ServerPk,
SharedKey: certInfo.SharedKey,
CryptoConstruction: certInfo.CryptoConstruction,
Name: name,
Timeout: proxy.timeout,
UDPAddr: remoteUDPAddr,
TCPAddr: remoteTCPAddr,
initialRtt: rtt,
}
return serverInfo, nil
}
func (serverInfo *ServerInfo) noticeFailure(proxy *Proxy) {
serverInfo.Lock()
serverInfo.rtt.Set(float64(proxy.timeout.Nanoseconds()))
serverInfo.Unlock()
}
func (serverInfo *ServerInfo) noticeBegin(proxy *Proxy) {
serverInfo.Lock()
serverInfo.lastActionTS = time.Now()
serverInfo.Unlock()
}
func (serverInfo *ServerInfo) noticeSuccess(proxy *Proxy) {
now := time.Now()
serverInfo.Lock()
elapsed := now.Sub(serverInfo.lastActionTS) / 1024
if elapsed > 0 {
serverInfo.rtt.Add(float64(elapsed))
}
serverInfo.Unlock()
}