func main() {
var url, origin string
flag.StringVar(&url, "url", "ws://127.0.0.1:9999/echo", "websocket URL")
flag.StringVar(&origin, "origin", "http://localhost/", "origin header")
flag.Parse()
if url == "" {
flag.Usage()
os.Exit(1)
}
ws, err := websocket.Dial(url, "", origin)
if err != nil {
log.Fatal(err)
}
go func() {
var msg = make([]byte, 512)
for {
n, err := ws.Read(msg)
if err != nil {
log.Fatal(err)
}
fmt.Printf("R: %s\nS: ", msg[:n])
}
}()
fmt.Print("S: ")
sc := bufio.NewScanner(os.Stdin)
for sc.Scan() {
if _, err := ws.Write(sc.Bytes()); err != nil {
log.Fatal(err)
}
}
}
// newWSProxy returns a websocket handler which forwards
// messages from an incoming WS connection to an outgoing
// WS connection. It builds upon the golang.org/x/net/websocket
// library for both incoming and outgoing connections.
func newWSProxy(t *url.URL) http.Handler {
return websocket.Handler(func(in *websocket.Conn) {
defer in.Close()
r := in.Request()
targetURL := "ws://" + t.Host + r.RequestURI
out, err := websocket.Dial(targetURL, "", r.Header.Get("Origin"))
if err != nil {
log.Printf("[INFO] WS error for %s. %s", r.URL, err)
return
}
defer out.Close()
errc := make(chan error, 2)
cp := func(dst io.Writer, src io.Reader) {
_, err := io.Copy(dst, src)
errc <- err
}
go cp(out, in)
go cp(in, out)
err = <-errc
if err != nil && err != io.EOF {
log.Printf("[INFO] WS error for %s. %s", r.URL, err)
}
})
}
func wsHandler(client *websocket.Conn) {
r := client.Request()
t := target(r)
if t == nil {
client.WriteClose(http.StatusNotFound)
return
}
logerr := func(err error) {
if err != nil && err != io.EOF {
log.Printf("[INFO] WS error for %s. %s", r.URL, err)
}
}
// dial the server
origin := r.Header.Get("Origin")
targetURL := "ws://" + t.URL.Host + r.RequestURI
server, err := websocket.Dial(targetURL, "", origin)
if err != nil {
logerr(err)
return
}
// send data from client to server
cerr := make(chan error)
go func() {
_, err := io.Copy(server, client)
cerr <- err
}()
// send data from server to client
serr := make(chan error)
go func() {
_, err = io.Copy(client, server)
serr <- err
}()
// wait for either server or client to exit
// and then close the other side
start := time.Now()
select {
case err := <-cerr:
logerr(err)
server.Close()
case err := <-serr:
logerr(err)
client.Close()
}
t.Timer.UpdateSince(start)
}
// This example demonstrates a trivial client.
func ExampleDial() {
origin := "http://localhost/"
url := "ws://localhost:12345/ws"
ws, err := websocket.Dial(url, "", origin)
if err != nil {
log.Fatal(err)
}
if _, err := ws.Write([]byte("hello, world!\n")); err != nil {
log.Fatal(err)
}
var msg = make([]byte, 512)
var n int
if n, err = ws.Read(msg); err != nil {
log.Fatal(err)
}
fmt.Printf("Received: %s.\n", msg[:n])
}