535 lines
12 KiB
Go
535 lines
12 KiB
Go
package client
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import (
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"bufio"
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"bytes"
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"crypto/tls"
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"encoding/base64"
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"errors"
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"fmt"
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"io"
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"io/ioutil"
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"net"
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"net/http"
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"net/url"
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"strings"
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"sync"
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"sync/atomic"
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"time"
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olog "git.loafle.net/overflow/log-go"
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"git.loafle.net/overflow/server-go/socket"
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"git.loafle.net/overflow/server-go/socket/client"
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"git.loafle.net/overflow/server-go/socket/web"
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)
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var errMalformedURL = errors.New("malformed ws or wss URL")
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type Connectors struct {
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client.Connectors
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URL string `json:"url,omitempty"`
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RequestHeader func() http.Header `json:"-"`
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Subprotocols []string `json:"subprotocols,omitempty"`
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// Jar specifies the cookie jar.
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// If Jar is nil, cookies are not sent in requests and ignored
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// in responses.
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CookieJar http.CookieJar `json:"-"`
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ResponseHandler func(*http.Response) `json:"-"`
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// NetDial specifies the dial function for creating TCP connections. If
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// NetDial is nil, net.Dial is used.
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NetDial func(network, addr string) (net.Conn, error) `json:"-"`
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// Proxy specifies a function to return a proxy for a given
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// Request. If the function returns a non-nil error, the
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// request is aborted with the provided error.
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// If Proxy is nil or returns a nil *URL, no proxy is used.
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Proxy func(*http.Request) (*url.URL, error) `json:"-"`
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serverURL *url.URL
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stopChan chan struct{}
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stopWg sync.WaitGroup
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readChan chan socket.SocketMessage
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writeChan chan socket.SocketMessage
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disconnectedChan chan struct{}
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reconnectedChan chan socket.Conn
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crw socket.ClientReadWriter
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validated atomic.Value
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}
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func (c *Connectors) Connect() (readChan <-chan socket.SocketMessage, writeChan chan<- socket.SocketMessage, err error) {
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var (
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conn socket.Conn
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res *http.Response
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)
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if c.stopChan != nil {
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return nil, nil, fmt.Errorf("%s already connected", c.logHeader())
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}
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conn, res, err = c.connect()
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if nil != err {
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return nil, nil, err
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}
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resH := c.ResponseHandler
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if nil != resH {
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resH(res)
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}
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c.readChan = make(chan socket.SocketMessage, 256)
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c.writeChan = make(chan socket.SocketMessage, 256)
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c.disconnectedChan = make(chan struct{})
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c.reconnectedChan = make(chan socket.Conn)
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c.stopChan = make(chan struct{})
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c.crw.ReadwriteHandler = c
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c.crw.ReadChan = c.readChan
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c.crw.WriteChan = c.writeChan
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c.crw.ClientStopChan = c.stopChan
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c.crw.ClientStopWg = &c.stopWg
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c.crw.DisconnectedChan = c.disconnectedChan
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c.crw.ReconnectedChan = c.reconnectedChan
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c.stopWg.Add(1)
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go c.handleReconnect()
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c.stopWg.Add(1)
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go c.crw.HandleConnection(conn)
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return c.readChan, c.writeChan, nil
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}
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func (c *Connectors) Disconnect() error {
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if c.stopChan == nil {
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return fmt.Errorf("%s must be connected before disconnection it", c.logHeader())
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}
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close(c.stopChan)
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c.stopWg.Wait()
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c.stopChan = nil
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return nil
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}
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func (c *Connectors) logHeader() string {
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return fmt.Sprintf("Connector[%s]:", c.Name)
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}
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func (c *Connectors) onDisconnected() {
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close(c.readChan)
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close(c.writeChan)
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c.reconnectedChan <- nil
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onDisconnected := c.OnDisconnected
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if nil != onDisconnected {
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go func() {
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onDisconnected(c)
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}()
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}
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}
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func (c *Connectors) handleReconnect() {
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defer func() {
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c.stopWg.Done()
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}()
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RC_LOOP:
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for {
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select {
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case <-c.disconnectedChan:
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case <-c.stopChan:
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return
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}
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if 0 >= c.GetReconnectTryTime() {
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c.onDisconnected()
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return
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}
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olog.Logger().Debugf("%s connection lost", c.logHeader())
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for indexI := 0; indexI < c.GetReconnectTryTime(); indexI++ {
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olog.Logger().Debugf("%s trying reconnect[%d]", c.logHeader(), indexI)
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conn, res, err := c.connect()
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if nil == err {
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resH := c.ResponseHandler
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if nil != resH {
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resH(res)
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}
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olog.Logger().Debugf("%s reconnected", c.logHeader())
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c.reconnectedChan <- conn
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continue RC_LOOP
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}
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time.Sleep(c.GetReconnectInterval())
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}
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olog.Logger().Debugf("%s reconnecting has been failed", c.logHeader())
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c.onDisconnected()
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return
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}
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}
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func (c *Connectors) connect() (socket.Conn, *http.Response, error) {
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conn, res, err := c.dial()
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if nil != err {
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return nil, nil, err
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}
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conn.SetCloseHandler(func(code int, text string) error {
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olog.Logger().Debugf("%s close", c.logHeader())
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return nil
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})
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return conn, res, nil
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}
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func (c *Connectors) dial() (socket.Conn, *http.Response, error) {
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var (
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err error
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challengeKey string
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netConn net.Conn
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)
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challengeKey, err = web.GenerateChallengeKey()
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if err != nil {
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return nil, nil, err
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}
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req := &http.Request{
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Method: "GET",
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URL: c.serverURL,
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Proto: "HTTP/1.1",
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ProtoMajor: 1,
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ProtoMinor: 1,
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Header: make(http.Header),
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Host: c.serverURL.Host,
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}
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cookieJar := c.CookieJar
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// Set the cookies present in the cookie jar of the dialer
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if nil != cookieJar {
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for _, cookie := range cookieJar.Cookies(c.serverURL) {
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req.AddCookie(cookie)
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}
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}
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// Set the request headers using the capitalization for names and values in
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// RFC examples. Although the capitalization shouldn't matter, there are
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// servers that depend on it. The Header.Set method is not used because the
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// method canonicalizes the header names.
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req.Header["Upgrade"] = []string{"websocket"}
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req.Header["Connection"] = []string{"Upgrade"}
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req.Header["Sec-WebSocket-Key"] = []string{challengeKey}
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req.Header["Sec-WebSocket-Version"] = []string{"13"}
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subprotocols := c.Subprotocols
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if len(subprotocols) > 0 {
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req.Header["Sec-WebSocket-Protocol"] = []string{strings.Join(subprotocols, ", ")}
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}
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for k, vs := range c.RequestHeader() {
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switch {
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case k == "Host":
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if len(vs) > 0 {
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req.Host = vs[0]
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}
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case k == "Upgrade" ||
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k == "Connection" ||
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k == "Sec-Websocket-Key" ||
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k == "Sec-Websocket-Version" ||
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k == "Sec-Websocket-Extensions" ||
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(k == "Sec-Websocket-Protocol" && len(subprotocols) > 0):
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return nil, nil, fmt.Errorf("%s duplicate header not allowed: %s", c.logHeader(), k)
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default:
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req.Header[k] = vs
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}
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}
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if c.IsEnableCompression() {
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req.Header.Set("Sec-Websocket-Extensions", "permessage-deflate; server_no_context_takeover; client_no_context_takeover")
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}
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hostPort, hostNoPort := hostPortNoPort(c.serverURL)
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var proxyURL *url.URL
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// Check wether the proxy method has been configured
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proxy := c.Proxy
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if nil != proxy {
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proxyURL, err = proxy(req)
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if err != nil {
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return nil, nil, err
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}
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}
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var targetHostPort string
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if proxyURL != nil {
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targetHostPort, _ = hostPortNoPort(proxyURL)
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} else {
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targetHostPort = hostPort
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}
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var deadline time.Time
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handshakeTimeout := c.GetHandshakeTimeout()
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if 0 != handshakeTimeout {
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deadline = time.Now().Add(handshakeTimeout)
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}
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netDial := c.NetDial
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if netDial == nil {
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netDialer := &net.Dialer{Deadline: deadline}
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netDial = netDialer.Dial
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}
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netConn, err = netDial("tcp", targetHostPort)
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if err != nil {
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return nil, nil, err
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}
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defer func() {
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if nil != netConn {
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netConn.Close()
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}
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}()
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err = netConn.SetDeadline(deadline)
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if nil != err {
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return nil, nil, err
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}
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if nil != proxyURL {
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connectHeader := make(http.Header)
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if user := proxyURL.User; nil != user {
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proxyUser := user.Username()
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if proxyPassword, passwordSet := user.Password(); passwordSet {
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credential := base64.StdEncoding.EncodeToString([]byte(proxyUser + ":" + proxyPassword))
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connectHeader.Set("Proxy-Authorization", "Basic "+credential)
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}
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}
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connectReq := &http.Request{
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Method: "CONNECT",
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URL: &url.URL{Opaque: hostPort},
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Host: hostPort,
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Header: connectHeader,
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}
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connectReq.Write(netConn)
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// Read response.
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// Okay to use and discard buffered reader here, because
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// TLS server will not speak until spoken to.
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br := bufio.NewReader(netConn)
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resp, err := http.ReadResponse(br, connectReq)
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if err != nil {
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return nil, nil, err
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}
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if resp.StatusCode != 200 {
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f := strings.SplitN(resp.Status, " ", 2)
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return nil, nil, errors.New(f[1])
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}
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}
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if "https" == c.serverURL.Scheme {
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cfg := cloneTLSConfig(c.GetTLSConfig())
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if cfg.ServerName == "" {
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cfg.ServerName = hostNoPort
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}
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tlsConn := tls.Client(netConn, cfg)
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netConn = tlsConn
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if err := tlsConn.Handshake(); err != nil {
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return nil, nil, err
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}
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if !cfg.InsecureSkipVerify {
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if err := tlsConn.VerifyHostname(cfg.ServerName); err != nil {
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return nil, nil, err
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}
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}
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}
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conn := socket.NewConn(netConn, false, c.GetReadBufferSize(), c.GetWriteBufferSize())
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if err := req.Write(netConn); err != nil {
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return nil, nil, err
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}
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resp, err := http.ReadResponse(conn.BuffReader, req)
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if err != nil {
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return nil, nil, err
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}
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if nil != cookieJar {
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if rc := resp.Cookies(); len(rc) > 0 {
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cookieJar.SetCookies(c.serverURL, rc)
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}
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}
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if resp.StatusCode != 101 ||
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!strings.EqualFold(resp.Header.Get("Upgrade"), "websocket") ||
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!strings.EqualFold(resp.Header.Get("Connection"), "upgrade") ||
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resp.Header.Get("Sec-Websocket-Accept") != web.ComputeAcceptKey(challengeKey) {
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// Before closing the network connection on return from this
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// function, slurp up some of the response to aid application
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// debugging.
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buf := make([]byte, 1024)
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n, _ := io.ReadFull(resp.Body, buf)
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resp.Body = ioutil.NopCloser(bytes.NewReader(buf[:n]))
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return nil, resp, socket.ErrBadHandshake
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}
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for _, ext := range web.HttpParseExtensions(resp.Header) {
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if ext[""] != "permessage-deflate" {
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continue
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}
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_, snct := ext["server_no_context_takeover"]
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_, cnct := ext["client_no_context_takeover"]
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if !snct || !cnct {
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return nil, resp, socket.ErrInvalidCompression
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}
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conn.SetNewCompressionWriter(socket.CompressNoContextTakeover)
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conn.SetNewDecompressionReader(socket.DecompressNoContextTakeover)
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break
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}
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resp.Body = ioutil.NopCloser(bytes.NewReader([]byte{}))
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conn.SetSubprotocol(resp.Header.Get("Sec-Websocket-Protocol"))
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netConn.SetDeadline(time.Time{})
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netConn = nil // to avoid close in defer.
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return conn, resp, nil
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}
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// parseURL parses the URL.
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//
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// This function is a replacement for the standard library url.Parse function.
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// In Go 1.4 and earlier, url.Parse loses information from the path.
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func parseURL(s string) (*url.URL, error) {
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// From the RFC:
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//
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// ws-URI = "ws:" "//" host [ ":" port ] path [ "?" query ]
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// wss-URI = "wss:" "//" host [ ":" port ] path [ "?" query ]
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var u url.URL
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switch {
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case strings.HasPrefix(s, "ws://"):
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u.Scheme = "ws"
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s = s[len("ws://"):]
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case strings.HasPrefix(s, "wss://"):
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u.Scheme = "wss"
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s = s[len("wss://"):]
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default:
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return nil, errMalformedURL
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}
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if i := strings.Index(s, "?"); i >= 0 {
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u.RawQuery = s[i+1:]
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s = s[:i]
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}
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if i := strings.Index(s, "/"); i >= 0 {
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u.Opaque = s[i:]
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s = s[:i]
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} else {
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u.Opaque = "/"
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}
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u.Host = s
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if strings.Contains(u.Host, "@") {
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// Don't bother parsing user information because user information is
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// not allowed in websocket URIs.
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return nil, errMalformedURL
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}
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return &u, nil
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}
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func hostPortNoPort(u *url.URL) (hostPort, hostNoPort string) {
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hostPort = u.Host
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hostNoPort = u.Host
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if i := strings.LastIndex(u.Host, ":"); i > strings.LastIndex(u.Host, "]") {
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hostNoPort = hostNoPort[:i]
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} else {
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switch u.Scheme {
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case "wss":
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hostPort += ":443"
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case "https":
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hostPort += ":443"
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default:
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hostPort += ":80"
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}
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}
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return hostPort, hostNoPort
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}
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func cloneTLSConfig(cfg *tls.Config) *tls.Config {
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if cfg == nil {
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return &tls.Config{}
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}
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return cfg.Clone()
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}
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func (c *Connectors) Clone() client.Connector {
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return &Connectors{
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Connectors: *c.Connectors.Clone(),
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URL: c.URL,
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RequestHeader: c.RequestHeader,
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Subprotocols: c.Subprotocols,
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CookieJar: c.CookieJar,
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ResponseHandler: c.ResponseHandler,
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NetDial: c.NetDial,
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Proxy: c.Proxy,
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serverURL: c.serverURL,
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validated: c.validated,
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}
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}
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func (c *Connectors) Validate() error {
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if nil != c.validated.Load() {
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return nil
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}
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c.validated.Store(true)
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if err := c.Connectors.Validate(); nil != err {
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return err
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}
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if "" == c.URL {
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return fmt.Errorf("URL is not valid")
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}
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u, err := parseURL(c.URL)
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if nil != err {
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return err
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}
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switch u.Scheme {
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case "ws":
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u.Scheme = "http"
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case "wss":
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u.Scheme = "https"
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default:
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return errMalformedURL
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}
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if nil != u.User {
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// User name and password are not allowed in websocket URIs.
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return errMalformedURL
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}
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c.serverURL = u
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if nil == c.Proxy {
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c.Proxy = http.ProxyFromEnvironment
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}
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return nil
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}
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