xenial (1) websockify.1.gz

Provided by: websockify_0.6.1+dfsg1-1ubuntu1_amd64 bug

NAME

       websockify - WebSockets to TCP socket bridge

SYNOPSIS

        websockify [options] [source_addr:]source_port target_addr:target_port
        websockify [options] [source_addr:]source_port -- WRAP_COMMAND_LINE

OPTIONS

        -h, --help         show this help message and exit
        -v, --verbose      verbose messages and per frame traffic
        --record=FILE      record sessions to FILE.[session_number]
        -D, --daemon       become a daemon (background process)
        --run-once         handle a single WebSocket connection and exit
        --timeout=TIMEOUT  after TIMEOUT seconds exit when not connected
        --cert=CERT        SSL certificate file
        --key=KEY          SSL key file (if separate from cert)
        --ssl-only         disallow non-encrypted connections
        --web=DIR          run webserver on same port. Serve files from DIR.
        --wrap-mode=MODE   action to take when the wrapped program exits or
                            daemonizes: exit (default), ignore, respawn

DESCRIPTION

       At  the  most  basic  level,  websockify just translates WebSockets traffic to normal TCP socket traffic.
       Websockify accepts the WebSockets handshake, parses it, and then begins forwarding  traffic  between  the
       client and the target in both directions.

       websockify was formerly named wsproxy and was part of the noVNC project.

NOTES

   WebSockets binary data
       Websockify supports all versions of the WebSockets protocol (Hixie and HyBI). The older Hixie versions of
       the protocol only support UTF-8 text payloads. In order to transport binary data over UTF-8  an  encoding
       must  used to encapsulate the data within UTF-8. Websockify uses base64 to encode all traffic to and from
       the client. This does not affect the data between websockify and the server.

   Encrypted WebSocket connections (wss://)
       To encrypt the traffic using the WebSocket 'wss://' URI scheme you need to  generate  a  certificate  for
       websockify  to  load.  By  default  websockify loads a certificate file name self.pem but the --cert=CERT
       option can override the file name. You can generate a self-signed certificate using openssl.  When  asked
       for the common name, use the hostname of the server where the proxy will be running:

       openssl req -new -x509 -days 365 -nodes -out self.pem -keyout self.pem

   Websock Javascript library
       The  websock.js  (see https://github.com/kanaka/websockify) Javascript library library provides a Websock
       object that is similar to the standard WebSocket object but Websock enables communication  with  raw  TCP
       sockets  (i.e. the binary stream) via websockify. This is accomplished by base64 encoding the data stream
       between Websock and websockify.

       Websock has built-in receive queue buffering; the message event does  not  contain  actual  data  but  is
       simply  a notification that there is new data available. Several rQ* methods are available to read binary
       data off of the receive queue.

       The Websock API is documented on the websock.js API wiki page:

       https://github.com/kanaka/websockify/wiki/websock.js

       See the "Wrap a Program" section below for an example of using Websock and websockify as a browser telnet
       client (wstelnet.html).

   Additional websockify features
       These are not necessary for the basic operation.

       *      Daemonizing:  When  the  -D  option  is  specified,  websockify runs in the background as a daemon
              process.

       *      SSL (the wss:// WebSockets URI): This is detected automatically  by  websockify  by  sniffing  the
              first  byte  sent  from  the client and then wrapping the socket if the data starts with '\x16' or
              '\x80' (indicating SSL).

       *      Flash security policy: websockify detects flash security policy requests (again  by  sniffing  the
              first  packet) and answers with an appropriate flash security policy response (and then closes the
              port). This means no separate flash security policy server is  needed  for  supporting  the  flash
              WebSockets fallback emulator.

       *      Session  recording:  This  feature that allows recording of the traffic sent and received from the
              client to a file using the --record option.

       *      Mini-webserver: websockify can detect and respond to normal web requests on the same port  as  the
              WebSockets  proxy  and  Flash  security  policy. This functionality is activate with the --web DIR
              option where DIR is the root of the web directory to serve.

       *      Wrap a program: see the "Wrap a Program" section below.

   Wrap a Program
       In addition to proxying from a source address to a target address (which may be on a  different  system),
       websockify  has  the  ability  to  launch a program on the local system and proxy WebSockets traffic to a
       normal TCP port owned/bound by the program.

       The is accomplished with a small LD_PRELOAD library (rebind.so) which intercepts bind() system  calls  by
       the  program.  The  specified  port  is moved to a new localhost/loopback free high port. websockify then
       proxies WebSockets traffic directed to the original port to the new (moved) port of the program.

       The program wrap mode is invoked by replacing the target with -- followed by the program command line  to
       wrap.

       `./websockify 2023 -- PROGRAM ARGS`

       The  --wrap-mode  option  can  be  used to indicate what action to take when the wrapped program exits or
       daemonizes.

       Here is an example of using websockify to wrap the vncserver command (which backgrounds itself)  for  use
       with noVNC:

       `./websockify 5901 --wrap-mode=ignore -- vncserver -geometry 1024x768 :1`

       Here  is  an example of wrapping telnetd (from krb5-telnetd).telnetd exits after the connection closes so
       the wrap mode is set to respawn the command:

       `sudo ./websockify 2023 --wrap-mode=respawn -- telnetd -debug 2023`

       The wstelnet.html page demonstrates a simple WebSockets based telnet client.

AUTHOR

       Joel Martin (github@martintribe.org)

SEE ALSO

       https://github.com/kanaka/websockify/

       https://github.com/kanaka/websockify/wiki/