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mirror of https://github.com/v2fly/v2ray-core.git synced 2024-06-10 09:50:43 +00:00
v2fly/transport/internet/kcp/listener.go

299 lines
6.5 KiB
Go

package kcp
import (
"crypto/cipher"
"crypto/tls"
"io"
"net"
"sync"
"time"
"v2ray.com/core/common"
"v2ray.com/core/common/buf"
"v2ray.com/core/common/errors"
"v2ray.com/core/common/log"
v2net "v2ray.com/core/common/net"
"v2ray.com/core/transport/internet"
"v2ray.com/core/transport/internet/internal"
v2tls "v2ray.com/core/transport/internet/tls"
"v2ray.com/core/transport/internet/udp"
)
type ConnectionID struct {
Remote v2net.Address
Port v2net.Port
Conv uint16
}
type ServerConnection struct {
id internal.ConnectionID
local net.Addr
remote net.Addr
writer PacketWriter
closer io.Closer
}
func (o *ServerConnection) Overhead() int {
return o.writer.Overhead()
}
func (o *ServerConnection) Read([]byte) (int, error) {
panic("KCP|ServerConnection: Read should not be called.")
}
func (o *ServerConnection) Write(b []byte) (int, error) {
return o.writer.Write(b)
}
func (o *ServerConnection) Close() error {
return o.closer.Close()
}
func (o *ServerConnection) Reset(input func([]Segment)) {
}
func (o *ServerConnection) LocalAddr() net.Addr {
return o.local
}
func (o *ServerConnection) RemoteAddr() net.Addr {
return o.remote
}
func (o *ServerConnection) SetDeadline(time.Time) error {
return nil
}
func (o *ServerConnection) SetReadDeadline(time.Time) error {
return nil
}
func (o *ServerConnection) SetWriteDeadline(time.Time) error {
return nil
}
func (o *ServerConnection) Id() internal.ConnectionID {
return o.id
}
// Listener defines a server listening for connections
type Listener struct {
sync.Mutex
running bool
sessions map[ConnectionID]*Connection
awaitingConns chan *Connection
hub *udp.Hub
tlsConfig *tls.Config
config *Config
reader PacketReader
header internet.PacketHeader
security cipher.AEAD
}
func NewListener(address v2net.Address, port v2net.Port, options internet.ListenOptions) (*Listener, error) {
networkSettings, err := options.Stream.GetEffectiveTransportSettings()
if err != nil {
log.Error("KCP|Listener: Failed to get KCP settings: ", err)
return nil, err
}
kcpSettings := networkSettings.(*Config)
kcpSettings.ConnectionReuse = &ConnectionReuse{Enable: false}
header, err := kcpSettings.GetPackerHeader()
if err != nil {
return nil, errors.Base(err).Message("KCP|Listener: Failed to create packet header.")
}
security, err := kcpSettings.GetSecurity()
if err != nil {
return nil, errors.Base(err).Message("KCP|Listener: Failed to create security.")
}
l := &Listener{
header: header,
security: security,
reader: &KCPPacketReader{
Header: header,
Security: security,
},
sessions: make(map[ConnectionID]*Connection),
awaitingConns: make(chan *Connection, 64),
running: true,
config: kcpSettings,
}
if options.Stream != nil && options.Stream.HasSecuritySettings() {
securitySettings, err := options.Stream.GetEffectiveSecuritySettings()
if err != nil {
log.Error("KCP|Listener: Failed to get security settings: ", err)
return nil, err
}
switch securitySettings := securitySettings.(type) {
case *v2tls.Config:
l.tlsConfig = securitySettings.GetTLSConfig()
}
}
hub, err := udp.ListenUDP(address, port, udp.ListenOption{Callback: l.OnReceive, Concurrency: 2})
if err != nil {
return nil, err
}
l.hub = hub
log.Info("KCP|Listener: listening on ", address, ":", port)
return l, nil
}
func (v *Listener) OnReceive(payload *buf.Buffer, src v2net.Destination, originalDest v2net.Destination) {
defer payload.Release()
segments := v.reader.Read(payload.Bytes())
if len(segments) == 0 {
log.Info("KCP|Listener: discarding invalid payload from ", src)
return
}
if !v.running {
return
}
v.Lock()
defer v.Unlock()
if !v.running {
return
}
if payload.Len() < 4 {
return
}
conv := segments[0].Conversation()
cmd := segments[0].Command()
id := ConnectionID{
Remote: src.Address,
Port: src.Port,
Conv: conv,
}
conn, found := v.sessions[id]
if !found {
if cmd == CommandTerminate {
return
}
writer := &Writer{
id: id,
hub: v.hub,
dest: src,
listener: v,
}
remoteAddr := &net.UDPAddr{
IP: src.Address.IP(),
Port: int(src.Port),
}
localAddr := v.hub.Addr()
sConn := &ServerConnection{
id: internal.NewConnectionID(v2net.LocalHostIP, src),
local: localAddr,
remote: remoteAddr,
writer: &KCPPacketWriter{
Header: v.header,
Writer: writer,
Security: v.security,
},
closer: writer,
}
conn = NewConnection(conv, sConn, v, v.config)
select {
case v.awaitingConns <- conn:
case <-time.After(time.Second * 5):
conn.Close()
return
}
v.sessions[id] = conn
}
conn.Input(segments)
}
func (v *Listener) Remove(id ConnectionID) {
if !v.running {
return
}
v.Lock()
defer v.Unlock()
if !v.running {
return
}
delete(v.sessions, id)
}
// Accept implements the Accept method in the Listener interface; it waits for the next call and returns a generic Conn.
func (v *Listener) Accept() (internet.Connection, error) {
for {
if !v.running {
return nil, ErrClosedListener
}
select {
case conn, open := <-v.awaitingConns:
if !open {
break
}
if v.tlsConfig != nil {
tlsConn := tls.Server(conn, v.tlsConfig)
return UnreusableConnection{Conn: tlsConn}, nil
}
return conn, nil
case <-time.After(time.Second):
}
}
}
// Close stops listening on the UDP address. Already Accepted connections are not closed.
func (v *Listener) Close() error {
if !v.running {
return ErrClosedListener
}
v.Lock()
defer v.Unlock()
v.running = false
close(v.awaitingConns)
for _, conn := range v.sessions {
go conn.Terminate()
}
v.hub.Close()
return nil
}
func (v *Listener) ActiveConnections() int {
v.Lock()
defer v.Unlock()
return len(v.sessions)
}
// Addr returns the listener's network address, The Addr returned is shared by all invocations of Addr, so do not modify it.
func (v *Listener) Addr() net.Addr {
return v.hub.Addr()
}
func (v *Listener) Put(internal.ConnectionID, net.Conn) {}
type Writer struct {
id ConnectionID
dest v2net.Destination
hub *udp.Hub
listener *Listener
}
func (v *Writer) Write(payload []byte) (int, error) {
return v.hub.WriteTo(payload, v.dest)
}
func (v *Writer) Close() error {
v.listener.Remove(v.id)
return nil
}
func ListenKCP(address v2net.Address, port v2net.Port, options internet.ListenOptions) (internet.Listener, error) {
return NewListener(address, port, options)
}
func init() {
common.Must(internet.RegisterTransportListener(internet.TransportProtocol_MKCP, ListenKCP))
}