When most of ss-h2 was combined into ss-h1 during development, the h2 difference
about needing HTTP_FINAL to signal h2 FIN flag was accidentally dropped. In
many cases the peer can infer it, from, eg, content-length reached. But we need
to replace explicitly doing it to cover all cases.
You can disconnect the stream by returning -1 from tx(). You can
give up your chance to send anything by returning 1 from tx().
Returning 0 sends `*len` amount of the provided buffer.
Returning <0 from rx() also disconnects the stream.
The endpoint field in streamtype policy may continue to just be the
hostname, like "warmcat.com".
But it's also possible now to be a url-formatted string, like, eg,
"https://warmcat.com:444/mailman/listinfo"
If so (ie, if it contains a : ) then the decoded elements may override
if tls is enabled, the endpoint address, the port, and the url path.
No ABI change.
Implement Captive Portal detection support in lws, with the actual
detection happening in platform code hooked up by lws_system_ops_t.
Add an implementation using Secure Streams as well, if the policy
defines captive_portal_detect streamtype, a SS using that streamtype
is used to probe if it's behind a captive portal.
Secure Streams is an optional layer on top of lws that separates policy
like endpoint selection and tls cert validation into a device JSON
policy document.
Code that wants to open a client connection just specifies a streamtype name,
and no longer deals with details like the endpoint, the protocol (!) or anything
else other than payloads and optionally generic metadata; the JSON policy
contains all the details for each streamtype. h1, h2, ws and mqtt client
connections are supported.
Logical secure streams outlive any particular connection and supports "nailed-up"
connectivity regardless of underlying connection stability.
