389 lines
7.0 KiB
Go
389 lines
7.0 KiB
Go
package tun2
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import (
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"context"
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"crypto/tls"
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"encoding/json"
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"errors"
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"fmt"
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"math/rand"
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"net"
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"net/http"
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"sync"
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"time"
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"git.xeserv.us/xena/route/database"
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"github.com/Xe/ln"
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failure "github.com/dgryski/go-failure"
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"github.com/mtneug/pkg/ulid"
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cmap "github.com/streamrail/concurrent-map"
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kcp "github.com/xtaci/kcp-go"
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"github.com/xtaci/smux"
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)
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type ServerConfig struct {
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TCPAddr string
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KCPAddr string
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TLSConfig *tls.Config
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SmuxConf *smux.Config
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Storage Storage
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}
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type Storage interface {
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GetRouteForHost(name string) (*database.Route, error)
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//ValidateToken(token string) (username string, ok bool, err error) // XXX RIP implement when users are implemented
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}
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type Server struct {
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cfg *ServerConfig
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connlock sync.Mutex
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conns map[net.Conn]*Connection
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domains cmap.ConcurrentMap
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}
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func NewServer(cfg *ServerConfig) (*Server, error) {
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if cfg == nil {
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return nil, errors.New("tun2: config must be specified")
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}
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if cfg.SmuxConf == nil {
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cfg.SmuxConf = smux.DefaultConfig()
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}
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cfg.SmuxConf.KeepAliveInterval = time.Second
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cfg.SmuxConf.KeepAliveTimeout = 15 * time.Second
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server := &Server{
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cfg: cfg,
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conns: map[net.Conn]*Connection{},
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domains: cmap.New(),
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}
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return server, nil
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}
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func (s *Server) ListenAndServe() error {
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ln.Log(ln.F{
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"action": "listen_and_serve_called",
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})
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if s.cfg.TCPAddr != "" {
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go func() {
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l, err := tls.Listen("tcp", s.cfg.TCPAddr, s.cfg.TLSConfig)
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if err != nil {
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panic(err)
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}
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ln.Log(ln.F{
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"action": "tcp+tls_listening",
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"addr": l.Addr(),
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})
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for {
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conn, err := l.Accept()
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if err != nil {
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ln.Error(err, ln.F{"kind": "tcp", "addr": l.Addr().String()})
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continue
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}
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ln.Log(ln.F{
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"action": "new_client",
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"kcp": false,
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"addr": conn.RemoteAddr(),
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})
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go s.HandleConn(conn, false)
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}
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}()
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}
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if s.cfg.KCPAddr != "" {
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go func() {
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l, err := kcp.Listen(s.cfg.KCPAddr)
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if err != nil {
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panic(err)
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}
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ln.Log(ln.F{
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"action": "kcp+tls_listening",
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"addr": l.Addr(),
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})
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for {
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conn, err := l.Accept()
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if err != nil {
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ln.Error(err, ln.F{"kind": "kcp", "addr": l.Addr().String()})
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}
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ln.Log(ln.F{
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"action": "new_client",
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"kcp": true,
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"addr": conn.RemoteAddr(),
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})
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tc := tls.Server(conn, s.cfg.TLSConfig)
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go s.HandleConn(tc, true)
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}
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}()
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}
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go func() {
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for {
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time.Sleep(time.Second)
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now := time.Now()
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s.connlock.Lock()
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for _, c := range s.conns {
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failureChance := c.detector.Phi(now)
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if failureChance != 0 {
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ln.Log(c.F(), ln.F{
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"action": "phi_failure_detection",
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"value": failureChance,
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})
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}
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}
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s.connlock.Unlock()
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}
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}()
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return nil
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}
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func (s *Server) HandleConn(c net.Conn, isKCP bool) {
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ctx, cancel := context.WithCancel(context.Background())
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defer cancel()
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session, err := smux.Server(c, s.cfg.SmuxConf)
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if err != nil {
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ln.Error(err, ln.F{
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"action": "session_failure",
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"local": c.LocalAddr().String(),
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"remote": c.RemoteAddr().String(),
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})
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c.Close()
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return
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}
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controlStream, err := session.OpenStream()
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if err != nil {
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ln.Error(err, ln.F{
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"action": "control_stream_failure",
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"local": c.LocalAddr().String(),
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"remote": c.RemoteAddr().String(),
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})
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session.Close()
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c.Close()
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return
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}
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csd := json.NewDecoder(controlStream)
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auth := &Auth{}
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err = csd.Decode(auth)
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if err != nil {
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ln.Error(err, ln.F{
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"action": "control_stream_auth_decoding_failure",
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"local": c.LocalAddr().String(),
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"remote": c.RemoteAddr().String(),
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})
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controlStream.Close()
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session.Close()
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c.Close()
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return
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}
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route, err := s.cfg.Storage.GetRouteForHost(auth.Domain)
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if err != nil {
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ln.Error(err, ln.F{
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"action": "nosuch_domain",
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"local": c.LocalAddr().String(),
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"remote": c.RemoteAddr().String(),
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})
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controlStream.Close()
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session.Close()
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c.Close()
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return
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}
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if route.Token != auth.Token {
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ln.Error(err, ln.F{
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"action": "bad_token",
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"local": c.LocalAddr().String(),
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"remote": c.RemoteAddr().String(),
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})
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fmt.Fprintln(controlStream, "bad token")
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controlStream.Close()
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session.Close()
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c.Close()
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return
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}
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connection := &Connection{
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id: ulid.New().String(),
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conn: c,
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isKCP: isKCP,
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session: session,
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user: defaultUser, // XXX RIP replace this with the actual token user once users are implemented
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domain: auth.Domain,
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cancel: cancel,
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detector: failure.New(15, 1),
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Auth: auth,
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}
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ln.Log(ln.F{
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"action": "backend_connected",
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}, connection.F())
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s.connlock.Lock()
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s.conns[c] = connection
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s.connlock.Unlock()
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var conns []*Connection
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val, ok := s.domains.Get(auth.Domain)
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if ok {
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conns, ok = val.([]*Connection)
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if !ok {
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conns = nil
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s.domains.Remove(auth.Domain)
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}
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}
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conns = append(conns, connection)
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s.domains.Set(auth.Domain, conns)
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ticker := time.NewTicker(5 * time.Second)
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defer ticker.Stop()
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for {
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select {
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case <-ticker.C:
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err := connection.Ping()
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if err != nil {
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cancel()
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}
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case <-ctx.Done():
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s.RemoveConn(connection)
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connection.Close()
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return
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}
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}
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}
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// RemoveConn removes a connection
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func (s *Server) RemoveConn(connection *Connection) {
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s.connlock.Lock()
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delete(s.conns, connection.conn)
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s.connlock.Unlock()
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auth := connection.Auth
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var conns []*Connection
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val, ok := s.domains.Get(auth.Domain)
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if ok {
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conns, ok = val.([]*Connection)
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if !ok {
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ln.Error(errors.New("fundamental assertion is not met"), connection.F(), ln.F{
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"action": "looking_up_for_disconnect_removal",
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})
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return
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}
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}
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for i, cntn := range conns {
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if cntn.id == connection.id {
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conns[i] = conns[len(conns)-1]
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conns = conns[:len(conns)-1]
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}
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}
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if len(conns) != 0 {
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s.domains.Set(auth.Domain, conns)
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} else {
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s.domains.Remove(auth.Domain)
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}
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ln.Log(connection.F(), ln.F{
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"action": "client_disconnecting",
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})
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}
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func (s *Server) RoundTrip(req *http.Request) (*http.Response, error) {
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var conns []*Connection
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val, ok := s.domains.Get(req.Host)
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if ok {
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conns, ok = val.([]*Connection)
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if !ok {
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ln.Error(errors.New("no backend connected"), ln.F{
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"action": "no_backend_connected",
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"remote": req.RemoteAddr,
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"host": req.Host,
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"uri": req.RequestURI,
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})
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return nil, errors.New("no backend connected")
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}
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}
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if len(conns) == 0 {
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ln.Error(errors.New("no backend connected"), ln.F{
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"action": "no_backend_connected",
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"remote": req.RemoteAddr,
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"host": req.Host,
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"uri": req.RequestURI,
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})
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return nil, errors.New("no backend connected")
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}
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c := conns[rand.Intn(len(conns))]
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resp, err := c.RoundTrip(req)
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if err != nil {
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ln.Error(err, c.F(), ln.F{
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"action": "connection_roundtrip",
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})
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defer c.cancel()
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return nil, err
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}
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ln.Log(c.F(), ln.F{
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"action": "http_traffic",
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"remote_addr": req.RemoteAddr,
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"host": req.Host,
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"uri": req.RequestURI,
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})
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return resp, nil
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}
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type Auth struct {
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Token string `json:"token"`
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Domain string `json:"domain"`
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}
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const defaultUser = "Cadey"
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