This is a NOP for existing usecases.
At the moment the only implemented transport for serialized SS is wsi, it's
typically used with Unix Domain Sockets, but it also works over tcp the
same.
It generalizes the interface between serialized chunks and the
transport, separately for client and proxy. The wsi transport is migrated
to use the new transport ops structs.
It will then be possible to "bring your own transport", so long as it is
reliable, and in-order, both for proxy and client / sspc.
We also adapt minimal-secure-streams-binance to build the -client variant
via SS proxy as well.
LWS_ONLY_SSPC is added so libwebsockets can be produced with just sspc
client support even for tiny targets.
A new embedded minimal example for rpi pico is also provided that
demonstrates using Serialized SS over a UART to an SS proxy, to implement
the SS Binance example on the pico, even though it has no networking itself.
This provides a way to get ahold of LWS_WITH_CONMON telemetry from Secure
Streams, it works the same with direct onward connections or via the proxy.
You can mark streamtypes with a "perf": true policy attribute... this
causes the onward connections on those streamtypes to collect information
about the connection performance, and the unsorted DNS results.
Streams with that policy attribute receive extra data in their rx callback,
with the LWSSS_FLAG_PERF_JSON flag set on it, containing JSON describing the
performance of the onward connection taken from CONMON data, in a JSON
representation. Streams without the "perf" attribute set never receive
this extra rx.
The received JSON is based on the CONMON struct info and looks like
{"peer":"46.105.127.147","dns_us":596,"sockconn_us":31382,"tls_us":28180,"txn_resp_us:23015,"dns":["2001:41d0:2:ee93::1","46.105.127.147"]}
A new minimal example minimal-secure-streams-perf is added that collects
this data on an HTTP GET from warmcat.com, and is built with a -client
version as well if LWS_WITH_SECURE_STREAMS_PROXY_API is set, that operates
via the ss proxy and produces the same result at the client.
This provides a build option LWS_WITH_CONMON that lets user code recover
detailed connection stats on client connections with the LCCSCF_CONMON
flag.
In addition to latencies for dns, socket connection, tls and first protocol
response where possible, it also provides the user code an unfiltered list
of DNS responses that the client received, and the peer it actually
succeded to connect to.
