This builds on the new dbus role support to provide a minimal example proxy
between ws and dbus.
A client app is provided that asks the proxy to connect to libwebsockets.org
and proxy the drawing data from the mirror example there back to the dbus
client using dbus messages.
This adds support for the integrating libdbus into the lws event loop.
Unlike the other roles, lws doesn't completely adopt the fd and libdbus insists
to retain control over the fd lifecycle. However libdbus provides apis for
foreign code (lws) to provide event loop services to libdbus for the fd.
Accordingly, unlike the other roles rx and writeable are not subsumed into
lws callback messages and the events remain the property of libdbus.
A context struct wrapper is provided that is available in the libdbus
callbacks to bridge between the lws and dbus worlds, along with
a minimal example dbus client and server.
This allows the client stuff to understand that addresses beginning with '+'
represent unix sockets.
If the first character after the '+' is '@', it understands that the '@'
should be read as '\0', in order to use Linux "abstract namespace"
sockets.
Further the lws_parse_uri() helper is extended to understand the convention
that an address starting with + is a unix socket, and treats the socket
path as delimited by ':', eg
http://+/var/run/mysocket:/my/path
HTTP Proxy is updated to allow mounts to these unix socket paths.
Proxy connections go out on h1, but are dynamically translated to h1 or h2
on the incoming side.
Proxy usage of libhubbub is separated out... LWS_WITH_HTTP_PROXY is on by
default, and LWS_WITH_HUBBUB is off by default.
During client redirect we "reset" the wsi to the redirect address,
involving closing the current fd that was told to redirect (it will
usually be a completely different server or port).
With libuv and its two-stage close that's not trivial. This solves
the problem we will "reset" (overwrite) where the handle lives in the
wsi with new a new connection / handle by having it copied out into
an allocated watcher struct, which is freed in the uv close callback.
To confirm it the minimal ws client example gets some new options, the
original problem was replicated with this
$ lws-minimal-ws-client-echo -s invalid.url.com -p 80
https://github.com/warmcat/libwebsockets/issues/1390
Currently the line buffer for vsnprintf() is 256, lines longer than that
end abruptly without a CRLF.
Change it to end with "...\n\0" when it truncates the line.
CSP header additions, logged on vhost init, longer than this are going
to become normal...
Now individual role callbacks are added in an earlier patch for protocol
bind and unbind, change the ws upgrade action to use the generic protocol
bind and unbind apis so the corresponding callbacks are issued for ws.
Firefox has a bug for 2 years
https://bugzilla.mozilla.org/show_bug.cgi?id=1262842
where a strict content-security-policy that is correctly followed
wrongly also defeats inline style inside SVG.
Apply the workaround told by the GIMP guys on the bug to convert
SVG styles to XML at export.
