libwebsockets

protocol_client_loopback_test

This is used to confirm that SSL client connections can coexist with
a vhost doing serving.

To set it up,

/*
 * This is a bit fiddly...
 *
 * 0) If you want the wss:// test to work, make sure the vhost is marked with
 *    enable-client-ssl if using lwsws, or call lws_init_vhost_client_ssl() on
 *    the vhost if you're doing it by hand.
 *
 * 1) enable the protocol on a vhost
 *
 *      "ws-protocols": [{
 *     "client-loopback-test": {
 *      "status": "ok"
 *     },  ...
 *
 *     the vhost should listen on 80 (ws://) or 443 (wss://)
 *
 * 2) mount the http part of the test one level down on the same vhost, eg
 *   {
 *      "mountpoint": "/c",
 *      "origin": "callback://client-loopback-test"
 *   }
 *
 * 3) Use a browser to visit the mountpoint with a URI attached for looping
 *    back, eg, if testing on localhost
 *
 *    http://localhost/c/ws://localhost
 *    https://localhost/c/wss://localhost
 *
 * 4) The HTTP part of this test protocol will try to do the requested
 *    ws client connection, to the same test protocol on the same
 *    server.
 */

Results should look like this

lwsws[29938]: client connection to localhost:443 with ssl: 1 started
lwsws[29938]: server part: LWS_CALLBACK_ESTABLISHED
lwsws[29938]: checking client ext permessage-deflate
lwsws[29938]: instantiating client ext permessage-deflate
lwsws[29938]: Client connection established
lwsws[29938]: Client connection received 7 from server 'Made it'

Signed-off-by: Andy Green <andy@warmcat.com>