mirror of https://github.com/elisescu/tty-share
Add support for public sharing with the new method
Vasile Popescu
4 years ago
committed by
Elis Popescu
parent
584cba56c9
commit
46e1bdaab2
@ -0,0 +1,120 @@
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package proxy
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import (
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"encoding/json"
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"io"
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"net"
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"github.com/hashicorp/yamux"
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log "github.com/sirupsen/logrus"
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)
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type HelloClient struct {
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Version string
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Data string
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}
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type HelloServer struct {
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Version string
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SessionID string
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PublicURL string
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Data string
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}
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type proxyConnection struct {
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muxSession *yamux.Session
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backConnAddress string
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SessionID string
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PublicURL string
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}
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func NewProxyConnection(backConnAddrr, proxyAddr string) (*proxyConnection, error) {
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conn, err := net.Dial("tcp", proxyAddr)
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if err != nil {
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return nil, err
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}
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// C -> S: HelloCLient
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// S -> C: HelloServer (sesionID)
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je := json.NewEncoder(conn)
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helloC := HelloClient{
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Version: "1",
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Data: "-",
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}
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err = je.Encode(helloC)
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if err != nil {
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return nil, err
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}
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jd := json.NewDecoder(conn)
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var helloS HelloServer
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err = jd.Decode(&helloS)
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if err != nil {
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return nil, err
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}
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log.Debugf("Got from the ReverseProxy: version=%s, sessionID=%s", helloS.Version, helloS.SessionID)
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session, err := yamux.Server(conn, nil)
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return &proxyConnection{
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muxSession: session,
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backConnAddress: backConnAddrr,
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SessionID: helloS.SessionID,
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PublicURL: helloS.PublicURL,
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}, nil
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}
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func (p *proxyConnection) RunProxy() {
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for {
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conn, err := p.muxSession.Accept()
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if err != nil {
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log.Errorf("Client: Accept returned %s. Done with this client.\n", err.Error())
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return
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}
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go func() {
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dst, err := net.Dial("tcp", p.backConnAddress)
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defer dst.Close()
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defer conn.Close()
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if err != nil {
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log.Errorf("Client: Can't connect to the target HTTP server: %s\n", err.Error())
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}
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glueConnAndWait(dst, conn)
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}()
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}
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}
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func (p *proxyConnection) Stop() {
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p.muxSession.Close()
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}
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func errToString(err error) string {
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if err != nil {
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return err.Error()
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}
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return "nil"
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}
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func glueConnAndWait(conn1, conn2 net.Conn) error {
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errChan := make(chan error, 2)
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log.Debugf("Starting the glue of the two conn %s %s", conn1.LocalAddr().String(), conn2.LocalAddr().String())
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copyAndNotify := func(dst, src net.Conn) {
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n, err := io.Copy(dst, src)
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log.Debugf("Wrote %d bytes, %s -> %s\n", n, src.LocalAddr().String(), dst.LocalAddr().String())
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if err != nil {
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log.Debugf(" -- ended with error: %s\n", err.Error())
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}
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errChan <- err
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}
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go copyAndNotify(conn1, conn2)
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go copyAndNotify(conn2, conn1)
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err1 := <-errChan
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err2 := <-errChan
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log.Debugf("Finished the glued connections with: %s and %s", errToString(err1), errToString(err2))
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return err1
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}
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@ -0,0 +1,12 @@
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# Proxy
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`tty-share` will open a `TCP` connection to a public proxy.
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This proxy will act like a reverse proxy, but it will not open new connections to any new back
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server, and instead it will simulate multiple multiplexed connections over the `TCP` connection
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already opened by `tty-share` mentioned above.
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The proxy will be completely dumb. It will only proxy connections coming from client browsers to the
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`tty-share`. It will be the `tty-share` command that will serve the content, and the ws
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connections. Any SSL/WSS from the web clients will be terminated by nginx or other typical reverse
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proxy.
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File diff suppressed because one or more lines are too long
@ -1 +0,0 @@
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Hi there
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@ -1,22 +0,0 @@
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<html>
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<head>
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<link rel="stylesheet" type="text/css" href="/static/bootstrap.min.css">
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</head>
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<style>
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.jumbotron {
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background-color: #0B486B;
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color: #ffffff;
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font-family: 'Raleway', sans-serif;
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}
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</style>
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<body>
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<div class="jumbotron jumbotron-fluid">
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<div class="container">
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<h1 class="display-4">Invalid session</h1>
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<p class="lead">This session doesn't exist, or has already ended.</p>
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</div>
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</div>
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</body>
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</html>
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@ -0,0 +1,22 @@
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<!-- This is taken from: https://colorlib.com/wp/free-404-error-page-templates/ -->
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<!DOCTYPE html>
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<html lang="en">
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<head>
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<link rel="stylesheet" type="text/css" href="/{{.PathPrefix}}/static/404.css">
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</head>
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<body>
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<section id="not-found">
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<div id="title">Something's wrong</div>
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<div class="circles">
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<p>404
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<br>
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<small>Page not found</small>
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</p>
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<span class="circle big"></span>
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<span class="circle med"></span>
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<span class="circle small"></span>
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</div>
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</section>
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</body>
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</html>
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@ -1,156 +0,0 @@
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/**
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*
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* Base64 encode / decode
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* http://www.webtoolkit.info/
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*
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**/
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var Base64 = {
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// private property
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_keyStr: "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=",
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// public method for encoding
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encode: function (input) {
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var output = "";
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var chr1, chr2, chr3, enc1, enc2, enc3, enc4;
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var i = 0;
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input = Base64._utf8_encode(input);
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while (i < input.length) {
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chr1 = input.charCodeAt(i++);
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chr2 = input.charCodeAt(i++);
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chr3 = input.charCodeAt(i++);
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enc1 = chr1 >> 2;
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enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
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enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
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enc4 = chr3 & 63;
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if (isNaN(chr2)) {
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enc3 = enc4 = 64;
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} else if (isNaN(chr3)) {
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enc4 = 64;
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}
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output = output +
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this._keyStr.charAt(enc1) + this._keyStr.charAt(enc2) +
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this._keyStr.charAt(enc3) + this._keyStr.charAt(enc4);
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}
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return output;
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},
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// public method for decoding
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decode: function (input) {
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var output = "";
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var chr1, chr2, chr3;
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var enc1, enc2, enc3, enc4;
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var i = 0;
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input = input.replace(/[^A-Za-z0-9\+\/\=]/g, "");
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while (i < input.length) {
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enc1 = this._keyStr.indexOf(input.charAt(i++));
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enc2 = this._keyStr.indexOf(input.charAt(i++));
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enc3 = this._keyStr.indexOf(input.charAt(i++));
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enc4 = this._keyStr.indexOf(input.charAt(i++));
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chr1 = (enc1 << 2) | (enc2 >> 4);
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chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
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chr3 = ((enc3 & 3) << 6) | enc4;
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output = output + String.fromCharCode(chr1);
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if (enc3 != 64) {
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output = output + String.fromCharCode(chr2);
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}
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if (enc4 != 64) {
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output = output + String.fromCharCode(chr3);
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}
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}
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output = Base64._utf8_decode(output);
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return output;
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},
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// private method for UTF-8 encoding
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_utf8_encode: function (string) {
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string = string.replace(/\r\n/g, "\n");
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var utftext = "";
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for (var n = 0; n < string.length; n++) {
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var c = string.charCodeAt(n);
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if (c < 128) {
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utftext += String.fromCharCode(c);
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}
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else if ((c > 127) && (c < 2048)) {
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utftext += String.fromCharCode((c >> 6) | 192);
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utftext += String.fromCharCode((c & 63) | 128);
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}
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else {
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utftext += String.fromCharCode((c >> 12) | 224);
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utftext += String.fromCharCode(((c >> 6) & 63) | 128);
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utftext += String.fromCharCode((c & 63) | 128);
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}
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}
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return utftext;
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},
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// private method for UTF-8 decoding
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_utf8_decode: function (utftext) {
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let string = "";
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let i = 0;
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let c = 0;
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let c1 = 0;
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let c2 = 0;
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let c3 = 0;
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while (i < utftext.length) {
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c = utftext.charCodeAt(i);
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if (c < 128) {
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string += String.fromCharCode(c);
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i++;
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}
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else if ((c > 191) && (c < 224)) {
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c2 = utftext.charCodeAt(i + 1);
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string += String.fromCharCode(((c & 31) << 6) | (c2 & 63));
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i += 2;
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}
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else {
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c2 = utftext.charCodeAt(i + 1);
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c3 = utftext.charCodeAt(i + 2);
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string += String.fromCharCode(((c & 15) << 12) | ((c2 & 63) << 6) | (c3 & 63));
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i += 3;
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}
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}
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return string;
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},
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base64ToArrayBuffer: function (input) {
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var binary_string = window.atob(input);
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var len = binary_string.length;
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var bytes = new Uint8Array( len );
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for (var i = 0; i < len; i++) {
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bytes[i] = binary_string.charCodeAt(i);
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}
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return bytes;
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}
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}
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export default Base64;
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@ -1,13 +0,0 @@
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html, body {
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width: 100%;
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height: 100%;
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margin: 0;
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}
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#terminal {
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position: fixed;
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top: 0;
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width: 100%;
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height: 100%;
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}
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@ -1,28 +0,0 @@
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import 'xterm/css/xterm.css';
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import './main.css';
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import { Terminal } from 'xterm';
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import * as pbkdf2 from 'pbkdf2';
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import { TTYReceiver } from './tty-receiver';
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const term = new Terminal({
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cursorBlink: true,
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macOptionIsMeta: true,
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});
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const derivedKey = pbkdf2.pbkdf2Sync('password', 'salt', 4096, 32, 'sha256');
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console.log(derivedKey);
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let wsAddress = "";
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if (window.location.protocol === "https:") {
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wsAddress = 'wss://';
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} else {
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wsAddress = "ws://";
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}
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let ttyWindow = window as any;
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wsAddress += ttyWindow.location.host + ttyWindow.ttyInitialData.wsPath;
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const ttyReceiver = new TTYReceiver(wsAddress, document.getElementById('terminal') as HTMLDivElement);
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@ -1,115 +0,0 @@
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import { Terminal, IEvent, IDisposable } from "xterm";
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import base64 from './base64';
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interface IRectSize {
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width: number;
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height: number;
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}
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class TTYReceiver {
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private xterminal: Terminal;
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private containerElement: HTMLElement;
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constructor(wsAddress: string, container: HTMLDivElement) {
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const connection = new WebSocket(wsAddress);
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this.xterminal = new Terminal({
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cursorBlink: true,
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macOptionIsMeta: true,
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scrollback: 0,
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fontSize: 12,
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letterSpacing: 0,
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});
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this.containerElement = container;
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this.xterminal.open(container);
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connection.onclose = (evt: CloseEvent) => {
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this.xterminal.blur();
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this.xterminal.setOption('cursorBlink', false);
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this.xterminal.clear();
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this.xterminal.write('Session closed');
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}
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this.xterminal.focus();
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const containerPixSize = this.getElementPixelsSize(container);
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const newFontSize = this.guessNewFontSize(this.xterminal.cols, this.xterminal.rows, containerPixSize.width, containerPixSize.height);
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this.xterminal.setOption('fontSize', newFontSize);
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connection.onmessage = (ev: MessageEvent) => {
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console.log("Got message: ", ev.data);
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let message = JSON.parse(ev.data)
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let msgData = base64.decode(message.Data)
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if (message.Type === "Write") {
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let writeMsg = JSON.parse(msgData)
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this.xterminal.writeUtf8(base64.base64ToArrayBuffer(writeMsg.Data));
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}
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if (message.Type == "WinSize") {
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let winSizeMsg = JSON.parse(msgData)
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const containerPixSize = this.getElementPixelsSize(container);
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const newFontSize = this.guessNewFontSize(winSizeMsg.Cols, winSizeMsg.Rows, containerPixSize.width, containerPixSize.height);
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this.xterminal.setOption('fontSize', newFontSize);
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// Now set the new size.
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this.xterminal.resize(winSizeMsg.Cols, winSizeMsg.Rows)
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}
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}
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this.xterminal.onData(function (data:string) {
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let writeMessage = {
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Type: "Write",
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Data: base64.encode(JSON.stringify({ Size: data.length, Data: base64.encode(data)})),
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}
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let dataToSend = JSON.stringify(writeMessage)
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connection.send(dataToSend);
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});
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}
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// Get the pixels size of the element, after all CSS was applied. This will be used in an ugly
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// hack to guess what fontSize to set on the xterm object. Horrible hack, but I feel less bad
|
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// about it seeing that VSV does it too:
|
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// https://github.com/microsoft/vscode/blob/d14ee7613fcead91c5c3c2bddbf288c0462be876/src/vs/workbench/parts/terminal/electron-browser/terminalInstance.ts#L363
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private getElementPixelsSize(element: HTMLElement): IRectSize {
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const defView = this.containerElement.ownerDocument.defaultView;
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let width = parseInt(defView.getComputedStyle(element).getPropertyValue('width').replace('px', ''), 10);
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let height = parseInt(defView.getComputedStyle(element).getPropertyValue('height').replace('px', ''), 10);
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return {
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width,
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height,
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}
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}
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|
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// Tries to guess the new font size, for the new terminal size, so that the rendered terminal
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// will have the newWidth and newHeight dimensions
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private guessNewFontSize(newCols: number, newRows: number, targetWidth: number, targetHeight: number): number {
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const cols = this.xterminal.cols;
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const rows = this.xterminal.rows;
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const fontSize = this.xterminal.getOption('fontSize');
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const xtermPixelsSize = this.getElementPixelsSize(this.containerElement.querySelector(".xterm-screen"));
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const newHFontSizeMultiplier = (cols / newCols) * (targetWidth / xtermPixelsSize.width);
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const newVFontSizeMultiplier = (rows / newRows) * (targetHeight / xtermPixelsSize.height);
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let newFontSize;
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if (newHFontSizeMultiplier > newVFontSizeMultiplier) {
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newFontSize = Math.floor(fontSize * newVFontSizeMultiplier);
|
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} else {
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newFontSize = Math.floor(fontSize * newHFontSizeMultiplier);
|
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}
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return newFontSize;
|
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}
|
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}
|
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|
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export {
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TTYReceiver
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}
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@ -0,0 +1,23 @@
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# Compiled Object files, Static and Dynamic libs (Shared Objects)
|
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*.o
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*.a
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*.so
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|
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# Folders
|
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_obj
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_test
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|
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# Architecture specific extensions/prefixes
|
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*.[568vq]
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[568vq].out
|
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|
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*.cgo1.go
|
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*.cgo2.c
|
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_cgo_defun.c
|
||||
_cgo_gotypes.go
|
||||
_cgo_export.*
|
||||
|
||||
_testmain.go
|
||||
|
||||
*.exe
|
||||
*.test
|
||||
@ -0,0 +1,362 @@
|
||||
Mozilla Public License, version 2.0
|
||||
|
||||
1. Definitions
|
||||
|
||||
1.1. "Contributor"
|
||||
|
||||
means each individual or legal entity that creates, contributes to the
|
||||
creation of, or owns Covered Software.
|
||||
|
||||
1.2. "Contributor Version"
|
||||
|
||||
means the combination of the Contributions of others (if any) used by a
|
||||
Contributor and that particular Contributor's Contribution.
|
||||
|
||||
1.3. "Contribution"
|
||||
|
||||
means Covered Software of a particular Contributor.
|
||||
|
||||
1.4. "Covered Software"
|
||||
|
||||
means Source Code Form to which the initial Contributor has attached the
|
||||
notice in Exhibit A, the Executable Form of such Source Code Form, and
|
||||
Modifications of such Source Code Form, in each case including portions
|
||||
thereof.
|
||||
|
||||
1.5. "Incompatible With Secondary Licenses"
|
||||
means
|
||||
|
||||
a. that the initial Contributor has attached the notice described in
|
||||
Exhibit B to the Covered Software; or
|
||||
|
||||
b. that the Covered Software was made available under the terms of
|
||||
version 1.1 or earlier of the License, but not also under the terms of
|
||||
a Secondary License.
|
||||
|
||||
1.6. "Executable Form"
|
||||
|
||||
means any form of the work other than Source Code Form.
|
||||
|
||||
1.7. "Larger Work"
|
||||
|
||||
means a work that combines Covered Software with other material, in a
|
||||
separate file or files, that is not Covered Software.
|
||||
|
||||
1.8. "License"
|
||||
|
||||
means this document.
|
||||
|
||||
1.9. "Licensable"
|
||||
|
||||
means having the right to grant, to the maximum extent possible, whether
|
||||
at the time of the initial grant or subsequently, any and all of the
|
||||
rights conveyed by this License.
|
||||
|
||||
1.10. "Modifications"
|
||||
|
||||
means any of the following:
|
||||
|
||||
a. any file in Source Code Form that results from an addition to,
|
||||
deletion from, or modification of the contents of Covered Software; or
|
||||
|
||||
b. any new file in Source Code Form that contains any Covered Software.
|
||||
|
||||
1.11. "Patent Claims" of a Contributor
|
||||
|
||||
means any patent claim(s), including without limitation, method,
|
||||
process, and apparatus claims, in any patent Licensable by such
|
||||
Contributor that would be infringed, but for the grant of the License,
|
||||
by the making, using, selling, offering for sale, having made, import,
|
||||
or transfer of either its Contributions or its Contributor Version.
|
||||
|
||||
1.12. "Secondary License"
|
||||
|
||||
means either the GNU General Public License, Version 2.0, the GNU Lesser
|
||||
General Public License, Version 2.1, the GNU Affero General Public
|
||||
License, Version 3.0, or any later versions of those licenses.
|
||||
|
||||
1.13. "Source Code Form"
|
||||
|
||||
means the form of the work preferred for making modifications.
|
||||
|
||||
1.14. "You" (or "Your")
|
||||
|
||||
means an individual or a legal entity exercising rights under this
|
||||
License. For legal entities, "You" includes any entity that controls, is
|
||||
controlled by, or is under common control with You. For purposes of this
|
||||
definition, "control" means (a) the power, direct or indirect, to cause
|
||||
the direction or management of such entity, whether by contract or
|
||||
otherwise, or (b) ownership of more than fifty percent (50%) of the
|
||||
outstanding shares or beneficial ownership of such entity.
|
||||
|
||||
|
||||
2. License Grants and Conditions
|
||||
|
||||
2.1. Grants
|
||||
|
||||
Each Contributor hereby grants You a world-wide, royalty-free,
|
||||
non-exclusive license:
|
||||
|
||||
a. under intellectual property rights (other than patent or trademark)
|
||||
Licensable by such Contributor to use, reproduce, make available,
|
||||
modify, display, perform, distribute, and otherwise exploit its
|
||||
Contributions, either on an unmodified basis, with Modifications, or
|
||||
as part of a Larger Work; and
|
||||
|
||||
b. under Patent Claims of such Contributor to make, use, sell, offer for
|
||||
sale, have made, import, and otherwise transfer either its
|
||||
Contributions or its Contributor Version.
|
||||
|
||||
2.2. Effective Date
|
||||
|
||||
The licenses granted in Section 2.1 with respect to any Contribution
|
||||
become effective for each Contribution on the date the Contributor first
|
||||
distributes such Contribution.
|
||||
|
||||
2.3. Limitations on Grant Scope
|
||||
|
||||
The licenses granted in this Section 2 are the only rights granted under
|
||||
this License. No additional rights or licenses will be implied from the
|
||||
distribution or licensing of Covered Software under this License.
|
||||
Notwithstanding Section 2.1(b) above, no patent license is granted by a
|
||||
Contributor:
|
||||
|
||||
a. for any code that a Contributor has removed from Covered Software; or
|
||||
|
||||
b. for infringements caused by: (i) Your and any other third party's
|
||||
modifications of Covered Software, or (ii) the combination of its
|
||||
Contributions with other software (except as part of its Contributor
|
||||
Version); or
|
||||
|
||||
c. under Patent Claims infringed by Covered Software in the absence of
|
||||
its Contributions.
|
||||
|
||||
This License does not grant any rights in the trademarks, service marks,
|
||||
or logos of any Contributor (except as may be necessary to comply with
|
||||
the notice requirements in Section 3.4).
|
||||
|
||||
2.4. Subsequent Licenses
|
||||
|
||||
No Contributor makes additional grants as a result of Your choice to
|
||||
distribute the Covered Software under a subsequent version of this
|
||||
License (see Section 10.2) or under the terms of a Secondary License (if
|
||||
permitted under the terms of Section 3.3).
|
||||
|
||||
2.5. Representation
|
||||
|
||||
Each Contributor represents that the Contributor believes its
|
||||
Contributions are its original creation(s) or it has sufficient rights to
|
||||
grant the rights to its Contributions conveyed by this License.
|
||||
|
||||
2.6. Fair Use
|
||||
|
||||
This License is not intended to limit any rights You have under
|
||||
applicable copyright doctrines of fair use, fair dealing, or other
|
||||
equivalents.
|
||||
|
||||
2.7. Conditions
|
||||
|
||||
Sections 3.1, 3.2, 3.3, and 3.4 are conditions of the licenses granted in
|
||||
Section 2.1.
|
||||
|
||||
|
||||
3. Responsibilities
|
||||
|
||||
3.1. Distribution of Source Form
|
||||
|
||||
All distribution of Covered Software in Source Code Form, including any
|
||||
Modifications that You create or to which You contribute, must be under
|
||||
the terms of this License. You must inform recipients that the Source
|
||||
Code Form of the Covered Software is governed by the terms of this
|
||||
License, and how they can obtain a copy of this License. You may not
|
||||
attempt to alter or restrict the recipients' rights in the Source Code
|
||||
Form.
|
||||
|
||||
3.2. Distribution of Executable Form
|
||||
|
||||
If You distribute Covered Software in Executable Form then:
|
||||
|
||||
a. such Covered Software must also be made available in Source Code Form,
|
||||
as described in Section 3.1, and You must inform recipients of the
|
||||
Executable Form how they can obtain a copy of such Source Code Form by
|
||||
reasonable means in a timely manner, at a charge no more than the cost
|
||||
of distribution to the recipient; and
|
||||
|
||||
b. You may distribute such Executable Form under the terms of this
|
||||
License, or sublicense it under different terms, provided that the
|
||||
license for the Executable Form does not attempt to limit or alter the
|
||||
recipients' rights in the Source Code Form under this License.
|
||||
|
||||
3.3. Distribution of a Larger Work
|
||||
|
||||
You may create and distribute a Larger Work under terms of Your choice,
|
||||
provided that You also comply with the requirements of this License for
|
||||
the Covered Software. If the Larger Work is a combination of Covered
|
||||
Software with a work governed by one or more Secondary Licenses, and the
|
||||
Covered Software is not Incompatible With Secondary Licenses, this
|
||||
License permits You to additionally distribute such Covered Software
|
||||
under the terms of such Secondary License(s), so that the recipient of
|
||||
the Larger Work may, at their option, further distribute the Covered
|
||||
Software under the terms of either this License or such Secondary
|
||||
License(s).
|
||||
|
||||
3.4. Notices
|
||||
|
||||
You may not remove or alter the substance of any license notices
|
||||
(including copyright notices, patent notices, disclaimers of warranty, or
|
||||
limitations of liability) contained within the Source Code Form of the
|
||||
Covered Software, except that You may alter any license notices to the
|
||||
extent required to remedy known factual inaccuracies.
|
||||
|
||||
3.5. Application of Additional Terms
|
||||
|
||||
You may choose to offer, and to charge a fee for, warranty, support,
|
||||
indemnity or liability obligations to one or more recipients of Covered
|
||||
Software. However, You may do so only on Your own behalf, and not on
|
||||
behalf of any Contributor. You must make it absolutely clear that any
|
||||
such warranty, support, indemnity, or liability obligation is offered by
|
||||
You alone, and You hereby agree to indemnify every Contributor for any
|
||||
liability incurred by such Contributor as a result of warranty, support,
|
||||
indemnity or liability terms You offer. You may include additional
|
||||
disclaimers of warranty and limitations of liability specific to any
|
||||
jurisdiction.
|
||||
|
||||
4. Inability to Comply Due to Statute or Regulation
|
||||
|
||||
If it is impossible for You to comply with any of the terms of this License
|
||||
with respect to some or all of the Covered Software due to statute,
|
||||
judicial order, or regulation then You must: (a) comply with the terms of
|
||||
this License to the maximum extent possible; and (b) describe the
|
||||
limitations and the code they affect. Such description must be placed in a
|
||||
text file included with all distributions of the Covered Software under
|
||||
this License. Except to the extent prohibited by statute or regulation,
|
||||
such description must be sufficiently detailed for a recipient of ordinary
|
||||
skill to be able to understand it.
|
||||
|
||||
5. Termination
|
||||
|
||||
5.1. The rights granted under this License will terminate automatically if You
|
||||
fail to comply with any of its terms. However, if You become compliant,
|
||||
then the rights granted under this License from a particular Contributor
|
||||
are reinstated (a) provisionally, unless and until such Contributor
|
||||
explicitly and finally terminates Your grants, and (b) on an ongoing
|
||||
basis, if such Contributor fails to notify You of the non-compliance by
|
||||
some reasonable means prior to 60 days after You have come back into
|
||||
compliance. Moreover, Your grants from a particular Contributor are
|
||||
reinstated on an ongoing basis if such Contributor notifies You of the
|
||||
non-compliance by some reasonable means, this is the first time You have
|
||||
received notice of non-compliance with this License from such
|
||||
Contributor, and You become compliant prior to 30 days after Your receipt
|
||||
of the notice.
|
||||
|
||||
5.2. If You initiate litigation against any entity by asserting a patent
|
||||
infringement claim (excluding declaratory judgment actions,
|
||||
counter-claims, and cross-claims) alleging that a Contributor Version
|
||||
directly or indirectly infringes any patent, then the rights granted to
|
||||
You by any and all Contributors for the Covered Software under Section
|
||||
2.1 of this License shall terminate.
|
||||
|
||||
5.3. In the event of termination under Sections 5.1 or 5.2 above, all end user
|
||||
license agreements (excluding distributors and resellers) which have been
|
||||
validly granted by You or Your distributors under this License prior to
|
||||
termination shall survive termination.
|
||||
|
||||
6. Disclaimer of Warranty
|
||||
|
||||
Covered Software is provided under this License on an "as is" basis,
|
||||
without warranty of any kind, either expressed, implied, or statutory,
|
||||
including, without limitation, warranties that the Covered Software is free
|
||||
of defects, merchantable, fit for a particular purpose or non-infringing.
|
||||
The entire risk as to the quality and performance of the Covered Software
|
||||
is with You. Should any Covered Software prove defective in any respect,
|
||||
You (not any Contributor) assume the cost of any necessary servicing,
|
||||
repair, or correction. This disclaimer of warranty constitutes an essential
|
||||
part of this License. No use of any Covered Software is authorized under
|
||||
this License except under this disclaimer.
|
||||
|
||||
7. Limitation of Liability
|
||||
|
||||
Under no circumstances and under no legal theory, whether tort (including
|
||||
negligence), contract, or otherwise, shall any Contributor, or anyone who
|
||||
distributes Covered Software as permitted above, be liable to You for any
|
||||
direct, indirect, special, incidental, or consequential damages of any
|
||||
character including, without limitation, damages for lost profits, loss of
|
||||
goodwill, work stoppage, computer failure or malfunction, or any and all
|
||||
other commercial damages or losses, even if such party shall have been
|
||||
informed of the possibility of such damages. This limitation of liability
|
||||
shall not apply to liability for death or personal injury resulting from
|
||||
such party's negligence to the extent applicable law prohibits such
|
||||
limitation. Some jurisdictions do not allow the exclusion or limitation of
|
||||
incidental or consequential damages, so this exclusion and limitation may
|
||||
not apply to You.
|
||||
|
||||
8. Litigation
|
||||
|
||||
Any litigation relating to this License may be brought only in the courts
|
||||
of a jurisdiction where the defendant maintains its principal place of
|
||||
business and such litigation shall be governed by laws of that
|
||||
jurisdiction, without reference to its conflict-of-law provisions. Nothing
|
||||
in this Section shall prevent a party's ability to bring cross-claims or
|
||||
counter-claims.
|
||||
|
||||
9. Miscellaneous
|
||||
|
||||
This License represents the complete agreement concerning the subject
|
||||
matter hereof. If any provision of this License is held to be
|
||||
unenforceable, such provision shall be reformed only to the extent
|
||||
necessary to make it enforceable. Any law or regulation which provides that
|
||||
the language of a contract shall be construed against the drafter shall not
|
||||
be used to construe this License against a Contributor.
|
||||
|
||||
|
||||
10. Versions of the License
|
||||
|
||||
10.1. New Versions
|
||||
|
||||
Mozilla Foundation is the license steward. Except as provided in Section
|
||||
10.3, no one other than the license steward has the right to modify or
|
||||
publish new versions of this License. Each version will be given a
|
||||
distinguishing version number.
|
||||
|
||||
10.2. Effect of New Versions
|
||||
|
||||
You may distribute the Covered Software under the terms of the version
|
||||
of the License under which You originally received the Covered Software,
|
||||
or under the terms of any subsequent version published by the license
|
||||
steward.
|
||||
|
||||
10.3. Modified Versions
|
||||
|
||||
If you create software not governed by this License, and you want to
|
||||
create a new license for such software, you may create and use a
|
||||
modified version of this License if you rename the license and remove
|
||||
any references to the name of the license steward (except to note that
|
||||
such modified license differs from this License).
|
||||
|
||||
10.4. Distributing Source Code Form that is Incompatible With Secondary
|
||||
Licenses If You choose to distribute Source Code Form that is
|
||||
Incompatible With Secondary Licenses under the terms of this version of
|
||||
the License, the notice described in Exhibit B of this License must be
|
||||
attached.
|
||||
|
||||
Exhibit A - Source Code Form License Notice
|
||||
|
||||
This Source Code Form is subject to the
|
||||
terms of the Mozilla Public License, v.
|
||||
2.0. If a copy of the MPL was not
|
||||
distributed with this file, You can
|
||||
obtain one at
|
||||
http://mozilla.org/MPL/2.0/.
|
||||
|
||||
If it is not possible or desirable to put the notice in a particular file,
|
||||
then You may include the notice in a location (such as a LICENSE file in a
|
||||
relevant directory) where a recipient would be likely to look for such a
|
||||
notice.
|
||||
|
||||
You may add additional accurate notices of copyright ownership.
|
||||
|
||||
Exhibit B - "Incompatible With Secondary Licenses" Notice
|
||||
|
||||
This Source Code Form is "Incompatible
|
||||
With Secondary Licenses", as defined by
|
||||
the Mozilla Public License, v. 2.0.
|
||||
@ -0,0 +1,86 @@
|
||||
# Yamux
|
||||
|
||||
Yamux (Yet another Multiplexer) is a multiplexing library for Golang.
|
||||
It relies on an underlying connection to provide reliability
|
||||
and ordering, such as TCP or Unix domain sockets, and provides
|
||||
stream-oriented multiplexing. It is inspired by SPDY but is not
|
||||
interoperable with it.
|
||||
|
||||
Yamux features include:
|
||||
|
||||
* Bi-directional streams
|
||||
* Streams can be opened by either client or server
|
||||
* Useful for NAT traversal
|
||||
* Server-side push support
|
||||
* Flow control
|
||||
* Avoid starvation
|
||||
* Back-pressure to prevent overwhelming a receiver
|
||||
* Keep Alives
|
||||
* Enables persistent connections over a load balancer
|
||||
* Efficient
|
||||
* Enables thousands of logical streams with low overhead
|
||||
|
||||
## Documentation
|
||||
|
||||
For complete documentation, see the associated [Godoc](http://godoc.org/github.com/hashicorp/yamux).
|
||||
|
||||
## Specification
|
||||
|
||||
The full specification for Yamux is provided in the `spec.md` file.
|
||||
It can be used as a guide to implementors of interoperable libraries.
|
||||
|
||||
## Usage
|
||||
|
||||
Using Yamux is remarkably simple:
|
||||
|
||||
```go
|
||||
|
||||
func client() {
|
||||
// Get a TCP connection
|
||||
conn, err := net.Dial(...)
|
||||
if err != nil {
|
||||
panic(err)
|
||||
}
|
||||
|
||||
// Setup client side of yamux
|
||||
session, err := yamux.Client(conn, nil)
|
||||
if err != nil {
|
||||
panic(err)
|
||||
}
|
||||
|
||||
// Open a new stream
|
||||
stream, err := session.Open()
|
||||
if err != nil {
|
||||
panic(err)
|
||||
}
|
||||
|
||||
// Stream implements net.Conn
|
||||
stream.Write([]byte("ping"))
|
||||
}
|
||||
|
||||
func server() {
|
||||
// Accept a TCP connection
|
||||
conn, err := listener.Accept()
|
||||
if err != nil {
|
||||
panic(err)
|
||||
}
|
||||
|
||||
// Setup server side of yamux
|
||||
session, err := yamux.Server(conn, nil)
|
||||
if err != nil {
|
||||
panic(err)
|
||||
}
|
||||
|
||||
// Accept a stream
|
||||
stream, err := session.Accept()
|
||||
if err != nil {
|
||||
panic(err)
|
||||
}
|
||||
|
||||
// Listen for a message
|
||||
buf := make([]byte, 4)
|
||||
stream.Read(buf)
|
||||
}
|
||||
|
||||
```
|
||||
|
||||
@ -0,0 +1,60 @@
|
||||
package yamux
|
||||
|
||||
import (
|
||||
"fmt"
|
||||
"net"
|
||||
)
|
||||
|
||||
// hasAddr is used to get the address from the underlying connection
|
||||
type hasAddr interface {
|
||||
LocalAddr() net.Addr
|
||||
RemoteAddr() net.Addr
|
||||
}
|
||||
|
||||
// yamuxAddr is used when we cannot get the underlying address
|
||||
type yamuxAddr struct {
|
||||
Addr string
|
||||
}
|
||||
|
||||
func (*yamuxAddr) Network() string {
|
||||
return "yamux"
|
||||
}
|
||||
|
||||
func (y *yamuxAddr) String() string {
|
||||
return fmt.Sprintf("yamux:%s", y.Addr)
|
||||
}
|
||||
|
||||
// Addr is used to get the address of the listener.
|
||||
func (s *Session) Addr() net.Addr {
|
||||
return s.LocalAddr()
|
||||
}
|
||||
|
||||
// LocalAddr is used to get the local address of the
|
||||
// underlying connection.
|
||||
func (s *Session) LocalAddr() net.Addr {
|
||||
addr, ok := s.conn.(hasAddr)
|
||||
if !ok {
|
||||
return &yamuxAddr{"local"}
|
||||
}
|
||||
return addr.LocalAddr()
|
||||
}
|
||||
|
||||
// RemoteAddr is used to get the address of remote end
|
||||
// of the underlying connection
|
||||
func (s *Session) RemoteAddr() net.Addr {
|
||||
addr, ok := s.conn.(hasAddr)
|
||||
if !ok {
|
||||
return &yamuxAddr{"remote"}
|
||||
}
|
||||
return addr.RemoteAddr()
|
||||
}
|
||||
|
||||
// LocalAddr returns the local address
|
||||
func (s *Stream) LocalAddr() net.Addr {
|
||||
return s.session.LocalAddr()
|
||||
}
|
||||
|
||||
// RemoteAddr returns the remote address
|
||||
func (s *Stream) RemoteAddr() net.Addr {
|
||||
return s.session.RemoteAddr()
|
||||
}
|
||||
@ -0,0 +1,157 @@
|
||||
package yamux
|
||||
|
||||
import (
|
||||
"encoding/binary"
|
||||
"fmt"
|
||||
)
|
||||
|
||||
var (
|
||||
// ErrInvalidVersion means we received a frame with an
|
||||
// invalid version
|
||||
ErrInvalidVersion = fmt.Errorf("invalid protocol version")
|
||||
|
||||
// ErrInvalidMsgType means we received a frame with an
|
||||
// invalid message type
|
||||
ErrInvalidMsgType = fmt.Errorf("invalid msg type")
|
||||
|
||||
// ErrSessionShutdown is used if there is a shutdown during
|
||||
// an operation
|
||||
ErrSessionShutdown = fmt.Errorf("session shutdown")
|
||||
|
||||
// ErrStreamsExhausted is returned if we have no more
|
||||
// stream ids to issue
|
||||
ErrStreamsExhausted = fmt.Errorf("streams exhausted")
|
||||
|
||||
// ErrDuplicateStream is used if a duplicate stream is
|
||||
// opened inbound
|
||||
ErrDuplicateStream = fmt.Errorf("duplicate stream initiated")
|
||||
|
||||
// ErrReceiveWindowExceeded indicates the window was exceeded
|
||||
ErrRecvWindowExceeded = fmt.Errorf("recv window exceeded")
|
||||
|
||||
// ErrTimeout is used when we reach an IO deadline
|
||||
ErrTimeout = fmt.Errorf("i/o deadline reached")
|
||||
|
||||
// ErrStreamClosed is returned when using a closed stream
|
||||
ErrStreamClosed = fmt.Errorf("stream closed")
|
||||
|
||||
// ErrUnexpectedFlag is set when we get an unexpected flag
|
||||
ErrUnexpectedFlag = fmt.Errorf("unexpected flag")
|
||||
|
||||
// ErrRemoteGoAway is used when we get a go away from the other side
|
||||
ErrRemoteGoAway = fmt.Errorf("remote end is not accepting connections")
|
||||
|
||||
// ErrConnectionReset is sent if a stream is reset. This can happen
|
||||
// if the backlog is exceeded, or if there was a remote GoAway.
|
||||
ErrConnectionReset = fmt.Errorf("connection reset")
|
||||
|
||||
// ErrConnectionWriteTimeout indicates that we hit the "safety valve"
|
||||
// timeout writing to the underlying stream connection.
|
||||
ErrConnectionWriteTimeout = fmt.Errorf("connection write timeout")
|
||||
|
||||
// ErrKeepAliveTimeout is sent if a missed keepalive caused the stream close
|
||||
ErrKeepAliveTimeout = fmt.Errorf("keepalive timeout")
|
||||
)
|
||||
|
||||
const (
|
||||
// protoVersion is the only version we support
|
||||
protoVersion uint8 = 0
|
||||
)
|
||||
|
||||
const (
|
||||
// Data is used for data frames. They are followed
|
||||
// by length bytes worth of payload.
|
||||
typeData uint8 = iota
|
||||
|
||||
// WindowUpdate is used to change the window of
|
||||
// a given stream. The length indicates the delta
|
||||
// update to the window.
|
||||
typeWindowUpdate
|
||||
|
||||
// Ping is sent as a keep-alive or to measure
|
||||
// the RTT. The StreamID and Length value are echoed
|
||||
// back in the response.
|
||||
typePing
|
||||
|
||||
// GoAway is sent to terminate a session. The StreamID
|
||||
// should be 0 and the length is an error code.
|
||||
typeGoAway
|
||||
)
|
||||
|
||||
const (
|
||||
// SYN is sent to signal a new stream. May
|
||||
// be sent with a data payload
|
||||
flagSYN uint16 = 1 << iota
|
||||
|
||||
// ACK is sent to acknowledge a new stream. May
|
||||
// be sent with a data payload
|
||||
flagACK
|
||||
|
||||
// FIN is sent to half-close the given stream.
|
||||
// May be sent with a data payload.
|
||||
flagFIN
|
||||
|
||||
// RST is used to hard close a given stream.
|
||||
flagRST
|
||||
)
|
||||
|
||||
const (
|
||||
// initialStreamWindow is the initial stream window size
|
||||
initialStreamWindow uint32 = 256 * 1024
|
||||
)
|
||||
|
||||
const (
|
||||
// goAwayNormal is sent on a normal termination
|
||||
goAwayNormal uint32 = iota
|
||||
|
||||
// goAwayProtoErr sent on a protocol error
|
||||
goAwayProtoErr
|
||||
|
||||
// goAwayInternalErr sent on an internal error
|
||||
goAwayInternalErr
|
||||
)
|
||||
|
||||
const (
|
||||
sizeOfVersion = 1
|
||||
sizeOfType = 1
|
||||
sizeOfFlags = 2
|
||||
sizeOfStreamID = 4
|
||||
sizeOfLength = 4
|
||||
headerSize = sizeOfVersion + sizeOfType + sizeOfFlags +
|
||||
sizeOfStreamID + sizeOfLength
|
||||
)
|
||||
|
||||
type header []byte
|
||||
|
||||
func (h header) Version() uint8 {
|
||||
return h[0]
|
||||
}
|
||||
|
||||
func (h header) MsgType() uint8 {
|
||||
return h[1]
|
||||
}
|
||||
|
||||
func (h header) Flags() uint16 {
|
||||
return binary.BigEndian.Uint16(h[2:4])
|
||||
}
|
||||
|
||||
func (h header) StreamID() uint32 {
|
||||
return binary.BigEndian.Uint32(h[4:8])
|
||||
}
|
||||
|
||||
func (h header) Length() uint32 {
|
||||
return binary.BigEndian.Uint32(h[8:12])
|
||||
}
|
||||
|
||||
func (h header) String() string {
|
||||
return fmt.Sprintf("Vsn:%d Type:%d Flags:%d StreamID:%d Length:%d",
|
||||
h.Version(), h.MsgType(), h.Flags(), h.StreamID(), h.Length())
|
||||
}
|
||||
|
||||
func (h header) encode(msgType uint8, flags uint16, streamID uint32, length uint32) {
|
||||
h[0] = protoVersion
|
||||
h[1] = msgType
|
||||
binary.BigEndian.PutUint16(h[2:4], flags)
|
||||
binary.BigEndian.PutUint32(h[4:8], streamID)
|
||||
binary.BigEndian.PutUint32(h[8:12], length)
|
||||
}
|
||||
@ -0,0 +1 @@
|
||||
module github.com/hashicorp/yamux
|
||||
@ -0,0 +1,98 @@
|
||||
package yamux
|
||||
|
||||
import (
|
||||
"fmt"
|
||||
"io"
|
||||
"log"
|
||||
"os"
|
||||
"time"
|
||||
)
|
||||
|
||||
// Config is used to tune the Yamux session
|
||||
type Config struct {
|
||||
// AcceptBacklog is used to limit how many streams may be
|
||||
// waiting an accept.
|
||||
AcceptBacklog int
|
||||
|
||||
// EnableKeepalive is used to do a period keep alive
|
||||
// messages using a ping.
|
||||
EnableKeepAlive bool
|
||||
|
||||
// KeepAliveInterval is how often to perform the keep alive
|
||||
KeepAliveInterval time.Duration
|
||||
|
||||
// ConnectionWriteTimeout is meant to be a "safety valve" timeout after
|
||||
// we which will suspect a problem with the underlying connection and
|
||||
// close it. This is only applied to writes, where's there's generally
|
||||
// an expectation that things will move along quickly.
|
||||
ConnectionWriteTimeout time.Duration
|
||||
|
||||
// MaxStreamWindowSize is used to control the maximum
|
||||
// window size that we allow for a stream.
|
||||
MaxStreamWindowSize uint32
|
||||
|
||||
// LogOutput is used to control the log destination. Either Logger or
|
||||
// LogOutput can be set, not both.
|
||||
LogOutput io.Writer
|
||||
|
||||
// Logger is used to pass in the logger to be used. Either Logger or
|
||||
// LogOutput can be set, not both.
|
||||
Logger *log.Logger
|
||||
}
|
||||
|
||||
// DefaultConfig is used to return a default configuration
|
||||
func DefaultConfig() *Config {
|
||||
return &Config{
|
||||
AcceptBacklog: 256,
|
||||
EnableKeepAlive: true,
|
||||
KeepAliveInterval: 30 * time.Second,
|
||||
ConnectionWriteTimeout: 10 * time.Second,
|
||||
MaxStreamWindowSize: initialStreamWindow,
|
||||
LogOutput: os.Stderr,
|
||||
}
|
||||
}
|
||||
|
||||
// VerifyConfig is used to verify the sanity of configuration
|
||||
func VerifyConfig(config *Config) error {
|
||||
if config.AcceptBacklog <= 0 {
|
||||
return fmt.Errorf("backlog must be positive")
|
||||
}
|
||||
if config.KeepAliveInterval == 0 {
|
||||
return fmt.Errorf("keep-alive interval must be positive")
|
||||
}
|
||||
if config.MaxStreamWindowSize < initialStreamWindow {
|
||||
return fmt.Errorf("MaxStreamWindowSize must be larger than %d", initialStreamWindow)
|
||||
}
|
||||
if config.LogOutput != nil && config.Logger != nil {
|
||||
return fmt.Errorf("both Logger and LogOutput may not be set, select one")
|
||||
} else if config.LogOutput == nil && config.Logger == nil {
|
||||
return fmt.Errorf("one of Logger or LogOutput must be set, select one")
|
||||
}
|
||||
return nil
|
||||
}
|
||||
|
||||
// Server is used to initialize a new server-side connection.
|
||||
// There must be at most one server-side connection. If a nil config is
|
||||
// provided, the DefaultConfiguration will be used.
|
||||
func Server(conn io.ReadWriteCloser, config *Config) (*Session, error) {
|
||||
if config == nil {
|
||||
config = DefaultConfig()
|
||||
}
|
||||
if err := VerifyConfig(config); err != nil {
|
||||
return nil, err
|
||||
}
|
||||
return newSession(config, conn, false), nil
|
||||
}
|
||||
|
||||
// Client is used to initialize a new client-side connection.
|
||||
// There must be at most one client-side connection.
|
||||
func Client(conn io.ReadWriteCloser, config *Config) (*Session, error) {
|
||||
if config == nil {
|
||||
config = DefaultConfig()
|
||||
}
|
||||
|
||||
if err := VerifyConfig(config); err != nil {
|
||||
return nil, err
|
||||
}
|
||||
return newSession(config, conn, true), nil
|
||||
}
|
||||
@ -0,0 +1,653 @@
|
||||
package yamux
|
||||
|
||||
import (
|
||||
"bufio"
|
||||
"fmt"
|
||||
"io"
|
||||
"io/ioutil"
|
||||
"log"
|
||||
"math"
|
||||
"net"
|
||||
"strings"
|
||||
"sync"
|
||||
"sync/atomic"
|
||||
"time"
|
||||
)
|
||||
|
||||
// Session is used to wrap a reliable ordered connection and to
|
||||
// multiplex it into multiple streams.
|
||||
type Session struct {
|
||||
// remoteGoAway indicates the remote side does
|
||||
// not want futher connections. Must be first for alignment.
|
||||
remoteGoAway int32
|
||||
|
||||
// localGoAway indicates that we should stop
|
||||
// accepting futher connections. Must be first for alignment.
|
||||
localGoAway int32
|
||||
|
||||
// nextStreamID is the next stream we should
|
||||
// send. This depends if we are a client/server.
|
||||
nextStreamID uint32
|
||||
|
||||
// config holds our configuration
|
||||
config *Config
|
||||
|
||||
// logger is used for our logs
|
||||
logger *log.Logger
|
||||
|
||||
// conn is the underlying connection
|
||||
conn io.ReadWriteCloser
|
||||
|
||||
// bufRead is a buffered reader
|
||||
bufRead *bufio.Reader
|
||||
|
||||
// pings is used to track inflight pings
|
||||
pings map[uint32]chan struct{}
|
||||
pingID uint32
|
||||
pingLock sync.Mutex
|
||||
|
||||
// streams maps a stream id to a stream, and inflight has an entry
|
||||
// for any outgoing stream that has not yet been established. Both are
|
||||
// protected by streamLock.
|
||||
streams map[uint32]*Stream
|
||||
inflight map[uint32]struct{}
|
||||
streamLock sync.Mutex
|
||||
|
||||
// synCh acts like a semaphore. It is sized to the AcceptBacklog which
|
||||
// is assumed to be symmetric between the client and server. This allows
|
||||
// the client to avoid exceeding the backlog and instead blocks the open.
|
||||
synCh chan struct{}
|
||||
|
||||
// acceptCh is used to pass ready streams to the client
|
||||
acceptCh chan *Stream
|
||||
|
||||
// sendCh is used to mark a stream as ready to send,
|
||||
// or to send a header out directly.
|
||||
sendCh chan sendReady
|
||||
|
||||
// recvDoneCh is closed when recv() exits to avoid a race
|
||||
// between stream registration and stream shutdown
|
||||
recvDoneCh chan struct{}
|
||||
|
||||
// shutdown is used to safely close a session
|
||||
shutdown bool
|
||||
shutdownErr error
|
||||
shutdownCh chan struct{}
|
||||
shutdownLock sync.Mutex
|
||||
}
|
||||
|
||||
// sendReady is used to either mark a stream as ready
|
||||
// or to directly send a header
|
||||
type sendReady struct {
|
||||
Hdr []byte
|
||||
Body io.Reader
|
||||
Err chan error
|
||||
}
|
||||
|
||||
// newSession is used to construct a new session
|
||||
func newSession(config *Config, conn io.ReadWriteCloser, client bool) *Session {
|
||||
logger := config.Logger
|
||||
if logger == nil {
|
||||
logger = log.New(config.LogOutput, "", log.LstdFlags)
|
||||
}
|
||||
|
||||
s := &Session{
|
||||
config: config,
|
||||
logger: logger,
|
||||
conn: conn,
|
||||
bufRead: bufio.NewReader(conn),
|
||||
pings: make(map[uint32]chan struct{}),
|
||||
streams: make(map[uint32]*Stream),
|
||||
inflight: make(map[uint32]struct{}),
|
||||
synCh: make(chan struct{}, config.AcceptBacklog),
|
||||
acceptCh: make(chan *Stream, config.AcceptBacklog),
|
||||
sendCh: make(chan sendReady, 64),
|
||||
recvDoneCh: make(chan struct{}),
|
||||
shutdownCh: make(chan struct{}),
|
||||
}
|
||||
if client {
|
||||
s.nextStreamID = 1
|
||||
} else {
|
||||
s.nextStreamID = 2
|
||||
}
|
||||
go s.recv()
|
||||
go s.send()
|
||||
if config.EnableKeepAlive {
|
||||
go s.keepalive()
|
||||
}
|
||||
return s
|
||||
}
|
||||
|
||||
// IsClosed does a safe check to see if we have shutdown
|
||||
func (s *Session) IsClosed() bool {
|
||||
select {
|
||||
case <-s.shutdownCh:
|
||||
return true
|
||||
default:
|
||||
return false
|
||||
}
|
||||
}
|
||||
|
||||
// CloseChan returns a read-only channel which is closed as
|
||||
// soon as the session is closed.
|
||||
func (s *Session) CloseChan() <-chan struct{} {
|
||||
return s.shutdownCh
|
||||
}
|
||||
|
||||
// NumStreams returns the number of currently open streams
|
||||
func (s *Session) NumStreams() int {
|
||||
s.streamLock.Lock()
|
||||
num := len(s.streams)
|
||||
s.streamLock.Unlock()
|
||||
return num
|
||||
}
|
||||
|
||||
// Open is used to create a new stream as a net.Conn
|
||||
func (s *Session) Open() (net.Conn, error) {
|
||||
conn, err := s.OpenStream()
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
return conn, nil
|
||||
}
|
||||
|
||||
// OpenStream is used to create a new stream
|
||||
func (s *Session) OpenStream() (*Stream, error) {
|
||||
if s.IsClosed() {
|
||||
return nil, ErrSessionShutdown
|
||||
}
|
||||
if atomic.LoadInt32(&s.remoteGoAway) == 1 {
|
||||
return nil, ErrRemoteGoAway
|
||||
}
|
||||
|
||||
// Block if we have too many inflight SYNs
|
||||
select {
|
||||
case s.synCh <- struct{}{}:
|
||||
case <-s.shutdownCh:
|
||||
return nil, ErrSessionShutdown
|
||||
}
|
||||
|
||||
GET_ID:
|
||||
// Get an ID, and check for stream exhaustion
|
||||
id := atomic.LoadUint32(&s.nextStreamID)
|
||||
if id >= math.MaxUint32-1 {
|
||||
return nil, ErrStreamsExhausted
|
||||
}
|
||||
if !atomic.CompareAndSwapUint32(&s.nextStreamID, id, id+2) {
|
||||
goto GET_ID
|
||||
}
|
||||
|
||||
// Register the stream
|
||||
stream := newStream(s, id, streamInit)
|
||||
s.streamLock.Lock()
|
||||
s.streams[id] = stream
|
||||
s.inflight[id] = struct{}{}
|
||||
s.streamLock.Unlock()
|
||||
|
||||
// Send the window update to create
|
||||
if err := stream.sendWindowUpdate(); err != nil {
|
||||
select {
|
||||
case <-s.synCh:
|
||||
default:
|
||||
s.logger.Printf("[ERR] yamux: aborted stream open without inflight syn semaphore")
|
||||
}
|
||||
return nil, err
|
||||
}
|
||||
return stream, nil
|
||||
}
|
||||
|
||||
// Accept is used to block until the next available stream
|
||||
// is ready to be accepted.
|
||||
func (s *Session) Accept() (net.Conn, error) {
|
||||
conn, err := s.AcceptStream()
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
return conn, err
|
||||
}
|
||||
|
||||
// AcceptStream is used to block until the next available stream
|
||||
// is ready to be accepted.
|
||||
func (s *Session) AcceptStream() (*Stream, error) {
|
||||
select {
|
||||
case stream := <-s.acceptCh:
|
||||
if err := stream.sendWindowUpdate(); err != nil {
|
||||
return nil, err
|
||||
}
|
||||
return stream, nil
|
||||
case <-s.shutdownCh:
|
||||
return nil, s.shutdownErr
|
||||
}
|
||||
}
|
||||
|
||||
// Close is used to close the session and all streams.
|
||||
// Attempts to send a GoAway before closing the connection.
|
||||
func (s *Session) Close() error {
|
||||
s.shutdownLock.Lock()
|
||||
defer s.shutdownLock.Unlock()
|
||||
|
||||
if s.shutdown {
|
||||
return nil
|
||||
}
|
||||
s.shutdown = true
|
||||
if s.shutdownErr == nil {
|
||||
s.shutdownErr = ErrSessionShutdown
|
||||
}
|
||||
close(s.shutdownCh)
|
||||
s.conn.Close()
|
||||
<-s.recvDoneCh
|
||||
|
||||
s.streamLock.Lock()
|
||||
defer s.streamLock.Unlock()
|
||||
for _, stream := range s.streams {
|
||||
stream.forceClose()
|
||||
}
|
||||
return nil
|
||||
}
|
||||
|
||||
// exitErr is used to handle an error that is causing the
|
||||
// session to terminate.
|
||||
func (s *Session) exitErr(err error) {
|
||||
s.shutdownLock.Lock()
|
||||
if s.shutdownErr == nil {
|
||||
s.shutdownErr = err
|
||||
}
|
||||
s.shutdownLock.Unlock()
|
||||
s.Close()
|
||||
}
|
||||
|
||||
// GoAway can be used to prevent accepting further
|
||||
// connections. It does not close the underlying conn.
|
||||
func (s *Session) GoAway() error {
|
||||
return s.waitForSend(s.goAway(goAwayNormal), nil)
|
||||
}
|
||||
|
||||
// goAway is used to send a goAway message
|
||||
func (s *Session) goAway(reason uint32) header {
|
||||
atomic.SwapInt32(&s.localGoAway, 1)
|
||||
hdr := header(make([]byte, headerSize))
|
||||
hdr.encode(typeGoAway, 0, 0, reason)
|
||||
return hdr
|
||||
}
|
||||
|
||||
// Ping is used to measure the RTT response time
|
||||
func (s *Session) Ping() (time.Duration, error) {
|
||||
// Get a channel for the ping
|
||||
ch := make(chan struct{})
|
||||
|
||||
// Get a new ping id, mark as pending
|
||||
s.pingLock.Lock()
|
||||
id := s.pingID
|
||||
s.pingID++
|
||||
s.pings[id] = ch
|
||||
s.pingLock.Unlock()
|
||||
|
||||
// Send the ping request
|
||||
hdr := header(make([]byte, headerSize))
|
||||
hdr.encode(typePing, flagSYN, 0, id)
|
||||
if err := s.waitForSend(hdr, nil); err != nil {
|
||||
return 0, err
|
||||
}
|
||||
|
||||
// Wait for a response
|
||||
start := time.Now()
|
||||
select {
|
||||
case <-ch:
|
||||
case <-time.After(s.config.ConnectionWriteTimeout):
|
||||
s.pingLock.Lock()
|
||||
delete(s.pings, id) // Ignore it if a response comes later.
|
||||
s.pingLock.Unlock()
|
||||
return 0, ErrTimeout
|
||||
case <-s.shutdownCh:
|
||||
return 0, ErrSessionShutdown
|
||||
}
|
||||
|
||||
// Compute the RTT
|
||||
return time.Now().Sub(start), nil
|
||||
}
|
||||
|
||||
// keepalive is a long running goroutine that periodically does
|
||||
// a ping to keep the connection alive.
|
||||
func (s *Session) keepalive() {
|
||||
for {
|
||||
select {
|
||||
case <-time.After(s.config.KeepAliveInterval):
|
||||
_, err := s.Ping()
|
||||
if err != nil {
|
||||
if err != ErrSessionShutdown {
|
||||
s.logger.Printf("[ERR] yamux: keepalive failed: %v", err)
|
||||
s.exitErr(ErrKeepAliveTimeout)
|
||||
}
|
||||
return
|
||||
}
|
||||
case <-s.shutdownCh:
|
||||
return
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// waitForSendErr waits to send a header, checking for a potential shutdown
|
||||
func (s *Session) waitForSend(hdr header, body io.Reader) error {
|
||||
errCh := make(chan error, 1)
|
||||
return s.waitForSendErr(hdr, body, errCh)
|
||||
}
|
||||
|
||||
// waitForSendErr waits to send a header with optional data, checking for a
|
||||
// potential shutdown. Since there's the expectation that sends can happen
|
||||
// in a timely manner, we enforce the connection write timeout here.
|
||||
func (s *Session) waitForSendErr(hdr header, body io.Reader, errCh chan error) error {
|
||||
t := timerPool.Get()
|
||||
timer := t.(*time.Timer)
|
||||
timer.Reset(s.config.ConnectionWriteTimeout)
|
||||
defer func() {
|
||||
timer.Stop()
|
||||
select {
|
||||
case <-timer.C:
|
||||
default:
|
||||
}
|
||||
timerPool.Put(t)
|
||||
}()
|
||||
|
||||
ready := sendReady{Hdr: hdr, Body: body, Err: errCh}
|
||||
select {
|
||||
case s.sendCh <- ready:
|
||||
case <-s.shutdownCh:
|
||||
return ErrSessionShutdown
|
||||
case <-timer.C:
|
||||
return ErrConnectionWriteTimeout
|
||||
}
|
||||
|
||||
select {
|
||||
case err := <-errCh:
|
||||
return err
|
||||
case <-s.shutdownCh:
|
||||
return ErrSessionShutdown
|
||||
case <-timer.C:
|
||||
return ErrConnectionWriteTimeout
|
||||
}
|
||||
}
|
||||
|
||||
// sendNoWait does a send without waiting. Since there's the expectation that
|
||||
// the send happens right here, we enforce the connection write timeout if we
|
||||
// can't queue the header to be sent.
|
||||
func (s *Session) sendNoWait(hdr header) error {
|
||||
t := timerPool.Get()
|
||||
timer := t.(*time.Timer)
|
||||
timer.Reset(s.config.ConnectionWriteTimeout)
|
||||
defer func() {
|
||||
timer.Stop()
|
||||
select {
|
||||
case <-timer.C:
|
||||
default:
|
||||
}
|
||||
timerPool.Put(t)
|
||||
}()
|
||||
|
||||
select {
|
||||
case s.sendCh <- sendReady{Hdr: hdr}:
|
||||
return nil
|
||||
case <-s.shutdownCh:
|
||||
return ErrSessionShutdown
|
||||
case <-timer.C:
|
||||
return ErrConnectionWriteTimeout
|
||||
}
|
||||
}
|
||||
|
||||
// send is a long running goroutine that sends data
|
||||
func (s *Session) send() {
|
||||
for {
|
||||
select {
|
||||
case ready := <-s.sendCh:
|
||||
// Send a header if ready
|
||||
if ready.Hdr != nil {
|
||||
sent := 0
|
||||
for sent < len(ready.Hdr) {
|
||||
n, err := s.conn.Write(ready.Hdr[sent:])
|
||||
if err != nil {
|
||||
s.logger.Printf("[ERR] yamux: Failed to write header: %v", err)
|
||||
asyncSendErr(ready.Err, err)
|
||||
s.exitErr(err)
|
||||
return
|
||||
}
|
||||
sent += n
|
||||
}
|
||||
}
|
||||
|
||||
// Send data from a body if given
|
||||
if ready.Body != nil {
|
||||
_, err := io.Copy(s.conn, ready.Body)
|
||||
if err != nil {
|
||||
s.logger.Printf("[ERR] yamux: Failed to write body: %v", err)
|
||||
asyncSendErr(ready.Err, err)
|
||||
s.exitErr(err)
|
||||
return
|
||||
}
|
||||
}
|
||||
|
||||
// No error, successful send
|
||||
asyncSendErr(ready.Err, nil)
|
||||
case <-s.shutdownCh:
|
||||
return
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// recv is a long running goroutine that accepts new data
|
||||
func (s *Session) recv() {
|
||||
if err := s.recvLoop(); err != nil {
|
||||
s.exitErr(err)
|
||||
}
|
||||
}
|
||||
|
||||
// Ensure that the index of the handler (typeData/typeWindowUpdate/etc) matches the message type
|
||||
var (
|
||||
handlers = []func(*Session, header) error{
|
||||
typeData: (*Session).handleStreamMessage,
|
||||
typeWindowUpdate: (*Session).handleStreamMessage,
|
||||
typePing: (*Session).handlePing,
|
||||
typeGoAway: (*Session).handleGoAway,
|
||||
}
|
||||
)
|
||||
|
||||
// recvLoop continues to receive data until a fatal error is encountered
|
||||
func (s *Session) recvLoop() error {
|
||||
defer close(s.recvDoneCh)
|
||||
hdr := header(make([]byte, headerSize))
|
||||
for {
|
||||
// Read the header
|
||||
if _, err := io.ReadFull(s.bufRead, hdr); err != nil {
|
||||
if err != io.EOF && !strings.Contains(err.Error(), "closed") && !strings.Contains(err.Error(), "reset by peer") {
|
||||
s.logger.Printf("[ERR] yamux: Failed to read header: %v", err)
|
||||
}
|
||||
return err
|
||||
}
|
||||
|
||||
// Verify the version
|
||||
if hdr.Version() != protoVersion {
|
||||
s.logger.Printf("[ERR] yamux: Invalid protocol version: %d", hdr.Version())
|
||||
return ErrInvalidVersion
|
||||
}
|
||||
|
||||
mt := hdr.MsgType()
|
||||
if mt < typeData || mt > typeGoAway {
|
||||
return ErrInvalidMsgType
|
||||
}
|
||||
|
||||
if err := handlers[mt](s, hdr); err != nil {
|
||||
return err
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// handleStreamMessage handles either a data or window update frame
|
||||
func (s *Session) handleStreamMessage(hdr header) error {
|
||||
// Check for a new stream creation
|
||||
id := hdr.StreamID()
|
||||
flags := hdr.Flags()
|
||||
if flags&flagSYN == flagSYN {
|
||||
if err := s.incomingStream(id); err != nil {
|
||||
return err
|
||||
}
|
||||
}
|
||||
|
||||
// Get the stream
|
||||
s.streamLock.Lock()
|
||||
stream := s.streams[id]
|
||||
s.streamLock.Unlock()
|
||||
|
||||
// If we do not have a stream, likely we sent a RST
|
||||
if stream == nil {
|
||||
// Drain any data on the wire
|
||||
if hdr.MsgType() == typeData && hdr.Length() > 0 {
|
||||
s.logger.Printf("[WARN] yamux: Discarding data for stream: %d", id)
|
||||
if _, err := io.CopyN(ioutil.Discard, s.bufRead, int64(hdr.Length())); err != nil {
|
||||
s.logger.Printf("[ERR] yamux: Failed to discard data: %v", err)
|
||||
return nil
|
||||
}
|
||||
} else {
|
||||
s.logger.Printf("[WARN] yamux: frame for missing stream: %v", hdr)
|
||||
}
|
||||
return nil
|
||||
}
|
||||
|
||||
// Check if this is a window update
|
||||
if hdr.MsgType() == typeWindowUpdate {
|
||||
if err := stream.incrSendWindow(hdr, flags); err != nil {
|
||||
if sendErr := s.sendNoWait(s.goAway(goAwayProtoErr)); sendErr != nil {
|
||||
s.logger.Printf("[WARN] yamux: failed to send go away: %v", sendErr)
|
||||
}
|
||||
return err
|
||||
}
|
||||
return nil
|
||||
}
|
||||
|
||||
// Read the new data
|
||||
if err := stream.readData(hdr, flags, s.bufRead); err != nil {
|
||||
if sendErr := s.sendNoWait(s.goAway(goAwayProtoErr)); sendErr != nil {
|
||||
s.logger.Printf("[WARN] yamux: failed to send go away: %v", sendErr)
|
||||
}
|
||||
return err
|
||||
}
|
||||
return nil
|
||||
}
|
||||
|
||||
// handlePing is invokde for a typePing frame
|
||||
func (s *Session) handlePing(hdr header) error {
|
||||
flags := hdr.Flags()
|
||||
pingID := hdr.Length()
|
||||
|
||||
// Check if this is a query, respond back in a separate context so we
|
||||
// don't interfere with the receiving thread blocking for the write.
|
||||
if flags&flagSYN == flagSYN {
|
||||
go func() {
|
||||
hdr := header(make([]byte, headerSize))
|
||||
hdr.encode(typePing, flagACK, 0, pingID)
|
||||
if err := s.sendNoWait(hdr); err != nil {
|
||||
s.logger.Printf("[WARN] yamux: failed to send ping reply: %v", err)
|
||||
}
|
||||
}()
|
||||
return nil
|
||||
}
|
||||
|
||||
// Handle a response
|
||||
s.pingLock.Lock()
|
||||
ch := s.pings[pingID]
|
||||
if ch != nil {
|
||||
delete(s.pings, pingID)
|
||||
close(ch)
|
||||
}
|
||||
s.pingLock.Unlock()
|
||||
return nil
|
||||
}
|
||||
|
||||
// handleGoAway is invokde for a typeGoAway frame
|
||||
func (s *Session) handleGoAway(hdr header) error {
|
||||
code := hdr.Length()
|
||||
switch code {
|
||||
case goAwayNormal:
|
||||
atomic.SwapInt32(&s.remoteGoAway, 1)
|
||||
case goAwayProtoErr:
|
||||
s.logger.Printf("[ERR] yamux: received protocol error go away")
|
||||
return fmt.Errorf("yamux protocol error")
|
||||
case goAwayInternalErr:
|
||||
s.logger.Printf("[ERR] yamux: received internal error go away")
|
||||
return fmt.Errorf("remote yamux internal error")
|
||||
default:
|
||||
s.logger.Printf("[ERR] yamux: received unexpected go away")
|
||||
return fmt.Errorf("unexpected go away received")
|
||||
}
|
||||
return nil
|
||||
}
|
||||
|
||||
// incomingStream is used to create a new incoming stream
|
||||
func (s *Session) incomingStream(id uint32) error {
|
||||
// Reject immediately if we are doing a go away
|
||||
if atomic.LoadInt32(&s.localGoAway) == 1 {
|
||||
hdr := header(make([]byte, headerSize))
|
||||
hdr.encode(typeWindowUpdate, flagRST, id, 0)
|
||||
return s.sendNoWait(hdr)
|
||||
}
|
||||
|
||||
// Allocate a new stream
|
||||
stream := newStream(s, id, streamSYNReceived)
|
||||
|
||||
s.streamLock.Lock()
|
||||
defer s.streamLock.Unlock()
|
||||
|
||||
// Check if stream already exists
|
||||
if _, ok := s.streams[id]; ok {
|
||||
s.logger.Printf("[ERR] yamux: duplicate stream declared")
|
||||
if sendErr := s.sendNoWait(s.goAway(goAwayProtoErr)); sendErr != nil {
|
||||
s.logger.Printf("[WARN] yamux: failed to send go away: %v", sendErr)
|
||||
}
|
||||
return ErrDuplicateStream
|
||||
}
|
||||
|
||||
// Register the stream
|
||||
s.streams[id] = stream
|
||||
|
||||
// Check if we've exceeded the backlog
|
||||
select {
|
||||
case s.acceptCh <- stream:
|
||||
return nil
|
||||
default:
|
||||
// Backlog exceeded! RST the stream
|
||||
s.logger.Printf("[WARN] yamux: backlog exceeded, forcing connection reset")
|
||||
delete(s.streams, id)
|
||||
stream.sendHdr.encode(typeWindowUpdate, flagRST, id, 0)
|
||||
return s.sendNoWait(stream.sendHdr)
|
||||
}
|
||||
}
|
||||
|
||||
// closeStream is used to close a stream once both sides have
|
||||
// issued a close. If there was an in-flight SYN and the stream
|
||||
// was not yet established, then this will give the credit back.
|
||||
func (s *Session) closeStream(id uint32) {
|
||||
s.streamLock.Lock()
|
||||
if _, ok := s.inflight[id]; ok {
|
||||
select {
|
||||
case <-s.synCh:
|
||||
default:
|
||||
s.logger.Printf("[ERR] yamux: SYN tracking out of sync")
|
||||
}
|
||||
}
|
||||
delete(s.streams, id)
|
||||
s.streamLock.Unlock()
|
||||
}
|
||||
|
||||
// establishStream is used to mark a stream that was in the
|
||||
// SYN Sent state as established.
|
||||
func (s *Session) establishStream(id uint32) {
|
||||
s.streamLock.Lock()
|
||||
if _, ok := s.inflight[id]; ok {
|
||||
delete(s.inflight, id)
|
||||
} else {
|
||||
s.logger.Printf("[ERR] yamux: established stream without inflight SYN (no tracking entry)")
|
||||
}
|
||||
select {
|
||||
case <-s.synCh:
|
||||
default:
|
||||
s.logger.Printf("[ERR] yamux: established stream without inflight SYN (didn't have semaphore)")
|
||||
}
|
||||
s.streamLock.Unlock()
|
||||
}
|
||||
@ -0,0 +1,140 @@
|
||||
# Specification
|
||||
|
||||
We use this document to detail the internal specification of Yamux.
|
||||
This is used both as a guide for implementing Yamux, but also for
|
||||
alternative interoperable libraries to be built.
|
||||
|
||||
# Framing
|
||||
|
||||
Yamux uses a streaming connection underneath, but imposes a message
|
||||
framing so that it can be shared between many logical streams. Each
|
||||
frame contains a header like:
|
||||
|
||||
* Version (8 bits)
|
||||
* Type (8 bits)
|
||||
* Flags (16 bits)
|
||||
* StreamID (32 bits)
|
||||
* Length (32 bits)
|
||||
|
||||
This means that each header has a 12 byte overhead.
|
||||
All fields are encoded in network order (big endian).
|
||||
Each field is described below:
|
||||
|
||||
## Version Field
|
||||
|
||||
The version field is used for future backward compatibility. At the
|
||||
current time, the field is always set to 0, to indicate the initial
|
||||
version.
|
||||
|
||||
## Type Field
|
||||
|
||||
The type field is used to switch the frame message type. The following
|
||||
message types are supported:
|
||||
|
||||
* 0x0 Data - Used to transmit data. May transmit zero length payloads
|
||||
depending on the flags.
|
||||
|
||||
* 0x1 Window Update - Used to updated the senders receive window size.
|
||||
This is used to implement per-session flow control.
|
||||
|
||||
* 0x2 Ping - Used to measure RTT. It can also be used to heart-beat
|
||||
and do keep-alives over TCP.
|
||||
|
||||
* 0x3 Go Away - Used to close a session.
|
||||
|
||||
## Flag Field
|
||||
|
||||
The flags field is used to provide additional information related
|
||||
to the message type. The following flags are supported:
|
||||
|
||||
* 0x1 SYN - Signals the start of a new stream. May be sent with a data or
|
||||
window update message. Also sent with a ping to indicate outbound.
|
||||
|
||||
* 0x2 ACK - Acknowledges the start of a new stream. May be sent with a data
|
||||
or window update message. Also sent with a ping to indicate response.
|
||||
|
||||
* 0x4 FIN - Performs a half-close of a stream. May be sent with a data
|
||||
message or window update.
|
||||
|
||||
* 0x8 RST - Reset a stream immediately. May be sent with a data or
|
||||
window update message.
|
||||
|
||||
## StreamID Field
|
||||
|
||||
The StreamID field is used to identify the logical stream the frame
|
||||
is addressing. The client side should use odd ID's, and the server even.
|
||||
This prevents any collisions. Additionally, the 0 ID is reserved to represent
|
||||
the session.
|
||||
|
||||
Both Ping and Go Away messages should always use the 0 StreamID.
|
||||
|
||||
## Length Field
|
||||
|
||||
The meaning of the length field depends on the message type:
|
||||
|
||||
* Data - provides the length of bytes following the header
|
||||
* Window update - provides a delta update to the window size
|
||||
* Ping - Contains an opaque value, echoed back
|
||||
* Go Away - Contains an error code
|
||||
|
||||
# Message Flow
|
||||
|
||||
There is no explicit connection setup, as Yamux relies on an underlying
|
||||
transport to be provided. However, there is a distinction between client
|
||||
and server side of the connection.
|
||||
|
||||
## Opening a stream
|
||||
|
||||
To open a stream, an initial data or window update frame is sent
|
||||
with a new StreamID. The SYN flag should be set to signal a new stream.
|
||||
|
||||
The receiver must then reply with either a data or window update frame
|
||||
with the StreamID along with the ACK flag to accept the stream or with
|
||||
the RST flag to reject the stream.
|
||||
|
||||
Because we are relying on the reliable stream underneath, a connection
|
||||
can begin sending data once the SYN flag is sent. The corresponding
|
||||
ACK does not need to be received. This is particularly well suited
|
||||
for an RPC system where a client wants to open a stream and immediately
|
||||
fire a request without waiting for the RTT of the ACK.
|
||||
|
||||
This does introduce the possibility of a connection being rejected
|
||||
after data has been sent already. This is a slight semantic difference
|
||||
from TCP, where the conection cannot be refused after it is opened.
|
||||
Clients should be prepared to handle this by checking for an error
|
||||
that indicates a RST was received.
|
||||
|
||||
## Closing a stream
|
||||
|
||||
To close a stream, either side sends a data or window update frame
|
||||
along with the FIN flag. This does a half-close indicating the sender
|
||||
will send no further data.
|
||||
|
||||
Once both sides have closed the connection, the stream is closed.
|
||||
|
||||
Alternatively, if an error occurs, the RST flag can be used to
|
||||
hard close a stream immediately.
|
||||
|
||||
## Flow Control
|
||||
|
||||
When Yamux is initially starts each stream with a 256KB window size.
|
||||
There is no window size for the session.
|
||||
|
||||
To prevent the streams from stalling, window update frames should be
|
||||
sent regularly. Yamux can be configured to provide a larger limit for
|
||||
windows sizes. Both sides assume the initial 256KB window, but can
|
||||
immediately send a window update as part of the SYN/ACK indicating a
|
||||
larger window.
|
||||
|
||||
Both sides should track the number of bytes sent in Data frames
|
||||
only, as only they are tracked as part of the window size.
|
||||
|
||||
## Session termination
|
||||
|
||||
When a session is being terminated, the Go Away message should
|
||||
be sent. The Length should be set to one of the following to
|
||||
provide an error code:
|
||||
|
||||
* 0x0 Normal termination
|
||||
* 0x1 Protocol error
|
||||
* 0x2 Internal error
|
||||
@ -0,0 +1,472 @@
|
||||
package yamux
|
||||
|
||||
import (
|
||||
"bytes"
|
||||
"io"
|
||||
"sync"
|
||||
"sync/atomic"
|
||||
"time"
|
||||
)
|
||||
|
||||
type streamState int
|
||||
|
||||
const (
|
||||
streamInit streamState = iota
|
||||
streamSYNSent
|
||||
streamSYNReceived
|
||||
streamEstablished
|
||||
streamLocalClose
|
||||
streamRemoteClose
|
||||
streamClosed
|
||||
streamReset
|
||||
)
|
||||
|
||||
// Stream is used to represent a logical stream
|
||||
// within a session.
|
||||
type Stream struct {
|
||||
recvWindow uint32
|
||||
sendWindow uint32
|
||||
|
||||
id uint32
|
||||
session *Session
|
||||
|
||||
state streamState
|
||||
stateLock sync.Mutex
|
||||
|
||||
recvBuf *bytes.Buffer
|
||||
recvLock sync.Mutex
|
||||
|
||||
controlHdr header
|
||||
controlErr chan error
|
||||
controlHdrLock sync.Mutex
|
||||
|
||||
sendHdr header
|
||||
sendErr chan error
|
||||
sendLock sync.Mutex
|
||||
|
||||
recvNotifyCh chan struct{}
|
||||
sendNotifyCh chan struct{}
|
||||
|
||||
readDeadline atomic.Value // time.Time
|
||||
writeDeadline atomic.Value // time.Time
|
||||
}
|
||||
|
||||
// newStream is used to construct a new stream within
|
||||
// a given session for an ID
|
||||
func newStream(session *Session, id uint32, state streamState) *Stream {
|
||||
s := &Stream{
|
||||
id: id,
|
||||
session: session,
|
||||
state: state,
|
||||
controlHdr: header(make([]byte, headerSize)),
|
||||
controlErr: make(chan error, 1),
|
||||
sendHdr: header(make([]byte, headerSize)),
|
||||
sendErr: make(chan error, 1),
|
||||
recvWindow: initialStreamWindow,
|
||||
sendWindow: initialStreamWindow,
|
||||
recvNotifyCh: make(chan struct{}, 1),
|
||||
sendNotifyCh: make(chan struct{}, 1),
|
||||
}
|
||||
s.readDeadline.Store(time.Time{})
|
||||
s.writeDeadline.Store(time.Time{})
|
||||
return s
|
||||
}
|
||||
|
||||
// Session returns the associated stream session
|
||||
func (s *Stream) Session() *Session {
|
||||
return s.session
|
||||
}
|
||||
|
||||
// StreamID returns the ID of this stream
|
||||
func (s *Stream) StreamID() uint32 {
|
||||
return s.id
|
||||
}
|
||||
|
||||
// Read is used to read from the stream
|
||||
func (s *Stream) Read(b []byte) (n int, err error) {
|
||||
defer asyncNotify(s.recvNotifyCh)
|
||||
START:
|
||||
s.stateLock.Lock()
|
||||
switch s.state {
|
||||
case streamLocalClose:
|
||||
fallthrough
|
||||
case streamRemoteClose:
|
||||
fallthrough
|
||||
case streamClosed:
|
||||
s.recvLock.Lock()
|
||||
if s.recvBuf == nil || s.recvBuf.Len() == 0 {
|
||||
s.recvLock.Unlock()
|
||||
s.stateLock.Unlock()
|
||||
return 0, io.EOF
|
||||
}
|
||||
s.recvLock.Unlock()
|
||||
case streamReset:
|
||||
s.stateLock.Unlock()
|
||||
return 0, ErrConnectionReset
|
||||
}
|
||||
s.stateLock.Unlock()
|
||||
|
||||
// If there is no data available, block
|
||||
s.recvLock.Lock()
|
||||
if s.recvBuf == nil || s.recvBuf.Len() == 0 {
|
||||
s.recvLock.Unlock()
|
||||
goto WAIT
|
||||
}
|
||||
|
||||
// Read any bytes
|
||||
n, _ = s.recvBuf.Read(b)
|
||||
s.recvLock.Unlock()
|
||||
|
||||
// Send a window update potentially
|
||||
err = s.sendWindowUpdate()
|
||||
return n, err
|
||||
|
||||
WAIT:
|
||||
var timeout <-chan time.Time
|
||||
var timer *time.Timer
|
||||
readDeadline := s.readDeadline.Load().(time.Time)
|
||||
if !readDeadline.IsZero() {
|
||||
delay := readDeadline.Sub(time.Now())
|
||||
timer = time.NewTimer(delay)
|
||||
timeout = timer.C
|
||||
}
|
||||
select {
|
||||
case <-s.recvNotifyCh:
|
||||
if timer != nil {
|
||||
timer.Stop()
|
||||
}
|
||||
goto START
|
||||
case <-timeout:
|
||||
return 0, ErrTimeout
|
||||
}
|
||||
}
|
||||
|
||||
// Write is used to write to the stream
|
||||
func (s *Stream) Write(b []byte) (n int, err error) {
|
||||
s.sendLock.Lock()
|
||||
defer s.sendLock.Unlock()
|
||||
total := 0
|
||||
for total < len(b) {
|
||||
n, err := s.write(b[total:])
|
||||
total += n
|
||||
if err != nil {
|
||||
return total, err
|
||||
}
|
||||
}
|
||||
return total, nil
|
||||
}
|
||||
|
||||
// write is used to write to the stream, may return on
|
||||
// a short write.
|
||||
func (s *Stream) write(b []byte) (n int, err error) {
|
||||
var flags uint16
|
||||
var max uint32
|
||||
var body io.Reader
|
||||
START:
|
||||
s.stateLock.Lock()
|
||||
switch s.state {
|
||||
case streamLocalClose:
|
||||
fallthrough
|
||||
case streamClosed:
|
||||
s.stateLock.Unlock()
|
||||
return 0, ErrStreamClosed
|
||||
case streamReset:
|
||||
s.stateLock.Unlock()
|
||||
return 0, ErrConnectionReset
|
||||
}
|
||||
s.stateLock.Unlock()
|
||||
|
||||
// If there is no data available, block
|
||||
window := atomic.LoadUint32(&s.sendWindow)
|
||||
if window == 0 {
|
||||
goto WAIT
|
||||
}
|
||||
|
||||
// Determine the flags if any
|
||||
flags = s.sendFlags()
|
||||
|
||||
// Send up to our send window
|
||||
max = min(window, uint32(len(b)))
|
||||
body = bytes.NewReader(b[:max])
|
||||
|
||||
// Send the header
|
||||
s.sendHdr.encode(typeData, flags, s.id, max)
|
||||
if err = s.session.waitForSendErr(s.sendHdr, body, s.sendErr); err != nil {
|
||||
return 0, err
|
||||
}
|
||||
|
||||
// Reduce our send window
|
||||
atomic.AddUint32(&s.sendWindow, ^uint32(max-1))
|
||||
|
||||
// Unlock
|
||||
return int(max), err
|
||||
|
||||
WAIT:
|
||||
var timeout <-chan time.Time
|
||||
writeDeadline := s.writeDeadline.Load().(time.Time)
|
||||
if !writeDeadline.IsZero() {
|
||||
delay := writeDeadline.Sub(time.Now())
|
||||
timeout = time.After(delay)
|
||||
}
|
||||
select {
|
||||
case <-s.sendNotifyCh:
|
||||
goto START
|
||||
case <-timeout:
|
||||
return 0, ErrTimeout
|
||||
}
|
||||
return 0, nil
|
||||
}
|
||||
|
||||
// sendFlags determines any flags that are appropriate
|
||||
// based on the current stream state
|
||||
func (s *Stream) sendFlags() uint16 {
|
||||
s.stateLock.Lock()
|
||||
defer s.stateLock.Unlock()
|
||||
var flags uint16
|
||||
switch s.state {
|
||||
case streamInit:
|
||||
flags |= flagSYN
|
||||
s.state = streamSYNSent
|
||||
case streamSYNReceived:
|
||||
flags |= flagACK
|
||||
s.state = streamEstablished
|
||||
}
|
||||
return flags
|
||||
}
|
||||
|
||||
// sendWindowUpdate potentially sends a window update enabling
|
||||
// further writes to take place. Must be invoked with the lock.
|
||||
func (s *Stream) sendWindowUpdate() error {
|
||||
s.controlHdrLock.Lock()
|
||||
defer s.controlHdrLock.Unlock()
|
||||
|
||||
// Determine the delta update
|
||||
max := s.session.config.MaxStreamWindowSize
|
||||
var bufLen uint32
|
||||
s.recvLock.Lock()
|
||||
if s.recvBuf != nil {
|
||||
bufLen = uint32(s.recvBuf.Len())
|
||||
}
|
||||
delta := (max - bufLen) - s.recvWindow
|
||||
|
||||
// Determine the flags if any
|
||||
flags := s.sendFlags()
|
||||
|
||||
// Check if we can omit the update
|
||||
if delta < (max/2) && flags == 0 {
|
||||
s.recvLock.Unlock()
|
||||
return nil
|
||||
}
|
||||
|
||||
// Update our window
|
||||
s.recvWindow += delta
|
||||
s.recvLock.Unlock()
|
||||
|
||||
// Send the header
|
||||
s.controlHdr.encode(typeWindowUpdate, flags, s.id, delta)
|
||||
if err := s.session.waitForSendErr(s.controlHdr, nil, s.controlErr); err != nil {
|
||||
return err
|
||||
}
|
||||
return nil
|
||||
}
|
||||
|
||||
// sendClose is used to send a FIN
|
||||
func (s *Stream) sendClose() error {
|
||||
s.controlHdrLock.Lock()
|
||||
defer s.controlHdrLock.Unlock()
|
||||
|
||||
flags := s.sendFlags()
|
||||
flags |= flagFIN
|
||||
s.controlHdr.encode(typeWindowUpdate, flags, s.id, 0)
|
||||
if err := s.session.waitForSendErr(s.controlHdr, nil, s.controlErr); err != nil {
|
||||
return err
|
||||
}
|
||||
return nil
|
||||
}
|
||||
|
||||
// Close is used to close the stream
|
||||
func (s *Stream) Close() error {
|
||||
closeStream := false
|
||||
s.stateLock.Lock()
|
||||
switch s.state {
|
||||
// Opened means we need to signal a close
|
||||
case streamSYNSent:
|
||||
fallthrough
|
||||
case streamSYNReceived:
|
||||
fallthrough
|
||||
case streamEstablished:
|
||||
s.state = streamLocalClose
|
||||
goto SEND_CLOSE
|
||||
|
||||
case streamLocalClose:
|
||||
case streamRemoteClose:
|
||||
s.state = streamClosed
|
||||
closeStream = true
|
||||
goto SEND_CLOSE
|
||||
|
||||
case streamClosed:
|
||||
case streamReset:
|
||||
default:
|
||||
panic("unhandled state")
|
||||
}
|
||||
s.stateLock.Unlock()
|
||||
return nil
|
||||
SEND_CLOSE:
|
||||
s.stateLock.Unlock()
|
||||
s.sendClose()
|
||||
s.notifyWaiting()
|
||||
if closeStream {
|
||||
s.session.closeStream(s.id)
|
||||
}
|
||||
return nil
|
||||
}
|
||||
|
||||
// forceClose is used for when the session is exiting
|
||||
func (s *Stream) forceClose() {
|
||||
s.stateLock.Lock()
|
||||
s.state = streamClosed
|
||||
s.stateLock.Unlock()
|
||||
s.notifyWaiting()
|
||||
}
|
||||
|
||||
// processFlags is used to update the state of the stream
|
||||
// based on set flags, if any. Lock must be held
|
||||
func (s *Stream) processFlags(flags uint16) error {
|
||||
// Close the stream without holding the state lock
|
||||
closeStream := false
|
||||
defer func() {
|
||||
if closeStream {
|
||||
s.session.closeStream(s.id)
|
||||
}
|
||||
}()
|
||||
|
||||
s.stateLock.Lock()
|
||||
defer s.stateLock.Unlock()
|
||||
if flags&flagACK == flagACK {
|
||||
if s.state == streamSYNSent {
|
||||
s.state = streamEstablished
|
||||
}
|
||||
s.session.establishStream(s.id)
|
||||
}
|
||||
if flags&flagFIN == flagFIN {
|
||||
switch s.state {
|
||||
case streamSYNSent:
|
||||
fallthrough
|
||||
case streamSYNReceived:
|
||||
fallthrough
|
||||
case streamEstablished:
|
||||
s.state = streamRemoteClose
|
||||
s.notifyWaiting()
|
||||
case streamLocalClose:
|
||||
s.state = streamClosed
|
||||
closeStream = true
|
||||
s.notifyWaiting()
|
||||
default:
|
||||
s.session.logger.Printf("[ERR] yamux: unexpected FIN flag in state %d", s.state)
|
||||
return ErrUnexpectedFlag
|
||||
}
|
||||
}
|
||||
if flags&flagRST == flagRST {
|
||||
s.state = streamReset
|
||||
closeStream = true
|
||||
s.notifyWaiting()
|
||||
}
|
||||
return nil
|
||||
}
|
||||
|
||||
// notifyWaiting notifies all the waiting channels
|
||||
func (s *Stream) notifyWaiting() {
|
||||
asyncNotify(s.recvNotifyCh)
|
||||
asyncNotify(s.sendNotifyCh)
|
||||
}
|
||||
|
||||
// incrSendWindow updates the size of our send window
|
||||
func (s *Stream) incrSendWindow(hdr header, flags uint16) error {
|
||||
if err := s.processFlags(flags); err != nil {
|
||||
return err
|
||||
}
|
||||
|
||||
// Increase window, unblock a sender
|
||||
atomic.AddUint32(&s.sendWindow, hdr.Length())
|
||||
asyncNotify(s.sendNotifyCh)
|
||||
return nil
|
||||
}
|
||||
|
||||
// readData is used to handle a data frame
|
||||
func (s *Stream) readData(hdr header, flags uint16, conn io.Reader) error {
|
||||
if err := s.processFlags(flags); err != nil {
|
||||
return err
|
||||
}
|
||||
|
||||
// Check that our recv window is not exceeded
|
||||
length := hdr.Length()
|
||||
if length == 0 {
|
||||
return nil
|
||||
}
|
||||
|
||||
// Wrap in a limited reader
|
||||
conn = &io.LimitedReader{R: conn, N: int64(length)}
|
||||
|
||||
// Copy into buffer
|
||||
s.recvLock.Lock()
|
||||
|
||||
if length > s.recvWindow {
|
||||
s.session.logger.Printf("[ERR] yamux: receive window exceeded (stream: %d, remain: %d, recv: %d)", s.id, s.recvWindow, length)
|
||||
return ErrRecvWindowExceeded
|
||||
}
|
||||
|
||||
if s.recvBuf == nil {
|
||||
// Allocate the receive buffer just-in-time to fit the full data frame.
|
||||
// This way we can read in the whole packet without further allocations.
|
||||
s.recvBuf = bytes.NewBuffer(make([]byte, 0, length))
|
||||
}
|
||||
if _, err := io.Copy(s.recvBuf, conn); err != nil {
|
||||
s.session.logger.Printf("[ERR] yamux: Failed to read stream data: %v", err)
|
||||
s.recvLock.Unlock()
|
||||
return err
|
||||
}
|
||||
|
||||
// Decrement the receive window
|
||||
s.recvWindow -= length
|
||||
s.recvLock.Unlock()
|
||||
|
||||
// Unblock any readers
|
||||
asyncNotify(s.recvNotifyCh)
|
||||
return nil
|
||||
}
|
||||
|
||||
// SetDeadline sets the read and write deadlines
|
||||
func (s *Stream) SetDeadline(t time.Time) error {
|
||||
if err := s.SetReadDeadline(t); err != nil {
|
||||
return err
|
||||
}
|
||||
if err := s.SetWriteDeadline(t); err != nil {
|
||||
return err
|
||||
}
|
||||
return nil
|
||||
}
|
||||
|
||||
// SetReadDeadline sets the deadline for blocked and future Read calls.
|
||||
func (s *Stream) SetReadDeadline(t time.Time) error {
|
||||
s.readDeadline.Store(t)
|
||||
asyncNotify(s.recvNotifyCh)
|
||||
return nil
|
||||
}
|
||||
|
||||
// SetWriteDeadline sets the deadline for blocked and future Write calls
|
||||
func (s *Stream) SetWriteDeadline(t time.Time) error {
|
||||
s.writeDeadline.Store(t)
|
||||
asyncNotify(s.sendNotifyCh)
|
||||
return nil
|
||||
}
|
||||
|
||||
// Shrink is used to compact the amount of buffers utilized
|
||||
// This is useful when using Yamux in a connection pool to reduce
|
||||
// the idle memory utilization.
|
||||
func (s *Stream) Shrink() {
|
||||
s.recvLock.Lock()
|
||||
if s.recvBuf != nil && s.recvBuf.Len() == 0 {
|
||||
s.recvBuf = nil
|
||||
}
|
||||
s.recvLock.Unlock()
|
||||
}
|
||||
@ -0,0 +1,43 @@
|
||||
package yamux
|
||||
|
||||
import (
|
||||
"sync"
|
||||
"time"
|
||||
)
|
||||
|
||||
var (
|
||||
timerPool = &sync.Pool{
|
||||
New: func() interface{} {
|
||||
timer := time.NewTimer(time.Hour * 1e6)
|
||||
timer.Stop()
|
||||
return timer
|
||||
},
|
||||
}
|
||||
)
|
||||
|
||||
// asyncSendErr is used to try an async send of an error
|
||||
func asyncSendErr(ch chan error, err error) {
|
||||
if ch == nil {
|
||||
return
|
||||
}
|
||||
select {
|
||||
case ch <- err:
|
||||
default:
|
||||
}
|
||||
}
|
||||
|
||||
// asyncNotify is used to signal a waiting goroutine
|
||||
func asyncNotify(ch chan struct{}) {
|
||||
select {
|
||||
case ch <- struct{}{}:
|
||||
default:
|
||||
}
|
||||
}
|
||||
|
||||
// min computes the minimum of two values
|
||||
func min(a, b uint32) uint32 {
|
||||
if a < b {
|
||||
return a
|
||||
}
|
||||
return b
|
||||
}
|
||||
Loading…
Reference in New Issue