1websockify(1) USER COMMANDS websockify(1)
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6 websockify - WebSockets to TCP socket bridge
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10 websockify [options] [source_addr:]source_port target_addr:target_port
11 websockify [options] [source_addr:]source_port -- WRAP_COMMAND_LINE
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15 -h, --help show this help message and exit
16 -v, --verbose verbose messages and per frame traffic
17 --record=FILE record sessions to FILE.[session_number]
18 -D, --daemon become a daemon (background process)
19 --run-once handle a single WebSocket connection and exit
20 --timeout=TIMEOUT after TIMEOUT seconds exit when not connected
21 --cert=CERT SSL certificate file
22 --key=KEY SSL key file (if separate from cert)
23 --ssl-only disallow non-encrypted connections
24 --web=DIR run webserver on same port. Serve files from DIR.
25 --wrap-mode=MODE action to take when the wrapped program exits or
26 daemonizes: exit (default), ignore, respawn
27
30 At the most basic level, websockify just translates WebSockets traffic
31 to normal TCP socket traffic. Websockify accepts the WebSockets hand‐
32 shake, parses it, and then begins forwarding traffic between the client
33 and the target in both directions.
34 websockify was formerly named wsproxy and was part of the noVNC
36 project.
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40 WebSockets binary data
41 Websockify supports all versions of the WebSockets protocol (Hixie and
42 HyBI). The older Hixie versions of the protocol only support UTF-8 text
43 payloads. In order to transport binary data over UTF-8 an encoding must
44 used to encapsulate the data within UTF-8. Websockify uses base64 to
45 encode all traffic to and from the client. This does not affect the
46 data between websockify and the server.
47 Encrypted WebSocket connections (wss://)
50 To encrypt the traffic using the WebSocket 'wss://' URI scheme you need
51 to generate a certificate for websockify to load. By default websockify
52 loads a certificate file name self.pem but the --cert=CERT option can
53 override the file name. You can generate a self-signed certificate
54 using openssl. When asked for the common name, use the hostname of the
55 server where the proxy will be running:
56 openssl req -new -x509 -days 365 -nodes -out self.pem -keyout self.pem
58 Websock Javascript library
61 The websock.js (see https://github.com/kanaka/websockify) Javascript
62 library library provides a Websock object that is similar to the stan‐
63 dard WebSocket object but Websock enables communication with raw TCP
64 sockets (i.e. the binary stream) via websockify. This is accomplished
65 by base64 encoding the data stream between Websock and websockify.
66 Websock has built-in receive queue buffering; the message event does
68 not contain actual data but is simply a notification that there is new
69 data available. Several rQ* methods are available to read binary data
70 off of the receive queue.
71 The Websock API is documented on the websock.js API wiki page:
73 https://github.com/kanaka/websockify/wiki/websock.js
75 See the "Wrap a Program" section below for an example of using Websock
77 and websockify as a browser telnet client (wstelnet.html).
78 Additional websockify features
81 These are not necessary for the basic operation.
82 * Daemonizing: When the -D option is specified, websockify runs in
85 the background as a daemon process.
86 * SSL (the wss:// WebSockets URI): This is detected automatically
89 by websockify by sniffing the first byte sent from the client
90 and then wrapping the socket if the data starts with '\x16' or
91 '\x80' (indicating SSL).
92 * Flash security policy: websockify detects flash security policy
95 requests (again by sniffing the first packet) and answers with
96 an appropriate flash security policy response (and then closes
97 the port). This means no separate flash security policy server
98 is needed for supporting the flash WebSockets fallback emulator.
99 * Session recording: This feature that allows recording of the
102 traffic sent and received from the client to a file using the
103 --record option.
104 * Mini-webserver: websockify can detect and respond to normal web
107 requests on the same port as the WebSockets proxy and Flash
108 security policy. This functionality is activate with the --web
109 DIR option where DIR is the root of the web directory to serve.
110 * Wrap a program: see the "Wrap a Program" section below.
113 Wrap a Program
116 In addition to proxying from a source address to a target address
117 (which may be on a different system), websockify has the ability to
118 launch a program on the local system and proxy WebSockets traffic to a
119 normal TCP port owned/bound by the program.
120 The is accomplished with a small LD_PRELOAD library (rebind.so) which
122 intercepts bind() system calls by the program. The specified port is
123 moved to a new localhost/loopback free high port. websockify then prox‐
124 ies WebSockets traffic directed to the original port to the new (moved)
125 port of the program.
126 The program wrap mode is invoked by replacing the target with -- fol‐
128 lowed by the program command line to wrap.
129 `./websockify 2023 -- PROGRAM ARGS`
131 The --wrap-mode option can be used to indicate what action to take when
133 the wrapped program exits or daemonizes.
134 Here is an example of using websockify to wrap the vncserver command
136 (which backgrounds itself) for use with noVNC:
137 `./websockify 5901 --wrap-mode=ignore -- vncserver -geometry 1024x768
139 :1`
140 Here is an example of wrapping telnetd (from krb5-telnetd).telnetd
142 exits after the connection closes so the wrap mode is set to respawn
143 the command:
144 `sudo ./websockify 2023 --wrap-mode=respawn -- telnetd -debug 2023`
146 The wstelnet.html page demonstrates a simple WebSockets based telnet
148 client.
149
153 Joel Martin (github@martintribe.org)
154
157 https://github.com/kanaka/websockify/
158 https://github.com/kanaka/websockify/wiki/
160version 0.3 June 7, 2012 websockify(1)