/
proxy.go
223 lines (203 loc) · 4.39 KB
/
proxy.go
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package proxy
import (
"context"
"fmt"
"io"
"log"
"net"
"net/http"
"net/url"
"regexp"
"strings"
"sync"
"time"
"github.com/gorilla/websocket"
"github.com/kazeburo/wsgate-client/token"
)
const (
bufferSize = 0xFFFF
)
var pool = sync.Pool{
New: func() interface{} { return make([]byte, 256*1024) },
}
// Proxy proxy struct
type Proxy struct {
server *net.TCPListener
listen string
timeout time.Duration
shutdownTimeout time.Duration
upstream string
enableCompression bool
header http.Header
gr token.Generator
done chan struct{}
}
// NewProxy create new proxy
func NewProxy(listen string, timeout, shutdownTimeout time.Duration, upstream string, enableCompression bool, header http.Header, gr token.Generator) (*Proxy, error) {
addr, err := net.ResolveTCPAddr("tcp", listen)
if err != nil {
return nil, err
}
server, err := net.ListenTCP("tcp", addr)
if err != nil {
return nil, err
}
return &Proxy{
server: server,
listen: listen,
timeout: timeout,
shutdownTimeout: shutdownTimeout,
upstream: upstream,
enableCompression: enableCompression,
header: header,
gr: gr,
done: make(chan struct{}),
}, nil
}
// Start start new proxy
func (p *Proxy) Start(ctx context.Context) error {
wg := &sync.WaitGroup{}
defer func() {
c := make(chan struct{})
go func() {
defer close(c)
wg.Wait()
}()
select {
case <-c:
return
case <-time.After(p.shutdownTimeout):
return
}
}()
go func() {
select {
case <-ctx.Done():
p.server.Close()
}
}()
for {
conn, err := p.server.AcceptTCP()
if err != nil {
if ne, ok := err.(net.Error); ok {
if ne.Temporary() {
continue
}
}
if strings.Contains(err.Error(), "use of closed network connection") {
select {
case <-ctx.Done():
return nil
default:
// fallthrough
}
}
return err
}
conn.SetNoDelay(true)
wg.Add(1)
go func(c net.Conn) {
defer wg.Done()
p.handleConn(ctx, c)
}(conn)
}
}
var wsRegexp = regexp.MustCompile("^http")
func (p *Proxy) connectWS(ctx context.Context) (*websocket.Conn, error) {
wsURL := wsRegexp.ReplaceAllString(p.upstream, "ws")
// log.Printf("connecting to %s", wsURL)
h2 := make(http.Header)
nv := 0
for _, vv := range p.header {
nv += len(vv)
}
sv := make([]string, nv)
for k, vv := range p.header {
n := copy(sv, vv)
h2[k] = sv[:n:n]
sv = sv[n:]
}
usURL, pErr := url.Parse(p.upstream)
if pErr != nil {
return nil, fmt.Errorf("Failed to parse upstream url: %v", pErr)
}
h2.Add("Origin", usURL.Scheme+"://"+usURL.Host)
if p.gr.Enabled() {
t, tErr := p.gr.Get(ctx)
if tErr != nil {
return nil, fmt.Errorf("Failed to generate token: %v", tErr)
}
h2.Add("Authorization", fmt.Sprintf("Bearer %s", t))
}
dialer := &websocket.Dialer{
HandshakeTimeout: p.timeout,
EnableCompression: p.enableCompression,
}
conn, _, err := dialer.Dial(wsURL, h2)
if err != nil {
return nil, fmt.Errorf("Dial to %s fail: %v", p.upstream, err)
}
return conn, err
}
func (p *Proxy) handleConn(ctx context.Context, c net.Conn) error {
s, err := p.connectWS(ctx)
if err != nil {
log.Printf("Failed to connect backend:%v listen:%s client:%s", err, p.listen, c.RemoteAddr().String())
c.Close()
return err
}
doneCh := make(chan bool)
goClose := false
// client => upstream
go func() {
defer func() { doneCh <- true }()
b := pool.Get().([]byte)
defer pool.Put(b)
for {
n, err := c.Read(b)
if err != nil {
if !goClose {
log.Printf("Copy from client: %v", err)
}
return
}
if err := s.WriteMessage(websocket.BinaryMessage, b[:n]); err != nil {
if !goClose {
log.Printf("Copy from client: %v", err)
}
return
}
}
}()
// upstream => client
go func() {
defer func() { doneCh <- true }()
b := pool.Get().([]byte)
defer pool.Put(b)
for {
mt, r, err := s.NextReader()
if err != nil {
if !goClose {
log.Printf("Copy from upstream: %v", err)
}
return
}
if mt != websocket.BinaryMessage {
log.Printf("Copy from upstream: BinaryMessage required")
return
}
if _, err := io.CopyBuffer(c, r, b); err != nil {
if !goClose {
log.Printf("Copy from upstream: %v", err)
}
return
}
}
}()
<-doneCh
goClose = true
s.Close()
c.Close()
<-doneCh
return nil
}