This implementation is similar to AMQP notifications: * Notifications are published on a single topic as a JSON feed * Topic is configurable, as is the QoS. Uses the paho.mqtt.golang library for the mqtt connection, and supports connections over tcp and websockets, with optional secure tls support. * Additionally the minio server configuration has been bumped up so mqtt configuration can be added. * Configuration migration code is added with tests. MQTT is an ISO standard M2M/IoT messaging protocol and was originally designed for applications for limited bandwidth networks. Today it's use is growing in the IoT space.
113 lines
3.4 KiB
Go
113 lines
3.4 KiB
Go
// Copyright 2009 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package websocket
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import (
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"bufio"
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"fmt"
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"io"
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"net/http"
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)
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func newServerConn(rwc io.ReadWriteCloser, buf *bufio.ReadWriter, req *http.Request, config *Config, handshake func(*Config, *http.Request) error) (conn *Conn, err error) {
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var hs serverHandshaker = &hybiServerHandshaker{Config: config}
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code, err := hs.ReadHandshake(buf.Reader, req)
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if err == ErrBadWebSocketVersion {
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fmt.Fprintf(buf, "HTTP/1.1 %03d %s\r\n", code, http.StatusText(code))
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fmt.Fprintf(buf, "Sec-WebSocket-Version: %s\r\n", SupportedProtocolVersion)
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buf.WriteString("\r\n")
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buf.WriteString(err.Error())
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buf.Flush()
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return
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}
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if err != nil {
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fmt.Fprintf(buf, "HTTP/1.1 %03d %s\r\n", code, http.StatusText(code))
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buf.WriteString("\r\n")
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buf.WriteString(err.Error())
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buf.Flush()
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return
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}
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if handshake != nil {
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err = handshake(config, req)
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if err != nil {
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code = http.StatusForbidden
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fmt.Fprintf(buf, "HTTP/1.1 %03d %s\r\n", code, http.StatusText(code))
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buf.WriteString("\r\n")
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buf.Flush()
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return
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}
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}
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err = hs.AcceptHandshake(buf.Writer)
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if err != nil {
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code = http.StatusBadRequest
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fmt.Fprintf(buf, "HTTP/1.1 %03d %s\r\n", code, http.StatusText(code))
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buf.WriteString("\r\n")
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buf.Flush()
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return
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}
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conn = hs.NewServerConn(buf, rwc, req)
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return
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}
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// Server represents a server of a WebSocket.
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type Server struct {
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// Config is a WebSocket configuration for new WebSocket connection.
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Config
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// Handshake is an optional function in WebSocket handshake.
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// For example, you can check, or don't check Origin header.
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// Another example, you can select config.Protocol.
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Handshake func(*Config, *http.Request) error
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// Handler handles a WebSocket connection.
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Handler
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}
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// ServeHTTP implements the http.Handler interface for a WebSocket
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func (s Server) ServeHTTP(w http.ResponseWriter, req *http.Request) {
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s.serveWebSocket(w, req)
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}
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func (s Server) serveWebSocket(w http.ResponseWriter, req *http.Request) {
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rwc, buf, err := w.(http.Hijacker).Hijack()
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if err != nil {
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panic("Hijack failed: " + err.Error())
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}
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// The server should abort the WebSocket connection if it finds
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// the client did not send a handshake that matches with protocol
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// specification.
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defer rwc.Close()
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conn, err := newServerConn(rwc, buf, req, &s.Config, s.Handshake)
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if err != nil {
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return
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}
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if conn == nil {
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panic("unexpected nil conn")
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}
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s.Handler(conn)
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}
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// Handler is a simple interface to a WebSocket browser client.
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// It checks if Origin header is valid URL by default.
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// You might want to verify websocket.Conn.Config().Origin in the func.
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// If you use Server instead of Handler, you could call websocket.Origin and
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// check the origin in your Handshake func. So, if you want to accept
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// non-browser clients, which do not send an Origin header, set a
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// Server.Handshake that does not check the origin.
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type Handler func(*Conn)
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func checkOrigin(config *Config, req *http.Request) (err error) {
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config.Origin, err = Origin(config, req)
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if err == nil && config.Origin == nil {
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return fmt.Errorf("null origin")
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}
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return err
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}
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// ServeHTTP implements the http.Handler interface for a WebSocket
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func (h Handler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
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s := Server{Handler: h, Handshake: checkOrigin}
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s.serveWebSocket(w, req)
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}
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