On lwsws, incoming ws connections to the default vhost
are not rejected by the dummy protocol handler and not
really serviced either, leading to bots connecting to it to
get immortal, idle ws connections with no timeout (since it's an
established ws connection).
Rejecting these connections by default by adding a handler
for ESTABLISHED in the dummy handler will solve it nicely,
but it will break an unknown number of dumb. protocol-less
user implementations that rely on this behaviour by using
break; from their own ESTABLISHED handler and calling
through to the currently NOP dummy handler one.
Add support to assertively disable the default protocol
index used for subprotocol-less ws connections instead.
Normalize the vhost options around optionally handling noncompliant
traffic at the listening socket for both non-tls and tls cases.
By default everything is as before.
However it's now possible to tell the vhost to allow noncompliant
connects to fall back to a specific role and protocol, both set
by name in the vhost creation info struct.
The original vhost flags allowing http redirect to https and
direct http serving from https server (which is a security
downgrade if enabled) are cleaned up and tested.
A minimal example minimal-raw-fallback-http-server is added with
switches to confirm operation of all the valid possibilities (see
the readme on that).
https://github.com/warmcat/libwebsockets/issues/1423
If you vhost->options has the flag LWS_SERVER_OPTION_VHOST_UPG_STRICT_HOST_CHECK,
then if the server is sent an upgrade request, the content of the Host: header is
required to match the vhost name + port. The port is set to the well-known values
of 80 and 443 if no :port on the host: value, depending on tls or not on the
connection.
minimal-ws-server can now take a -h flag to set this. lejp-conf (eg, lwsws) can now take
a flag strict-host-check on the vhost to enable it as well.
Since new roles may be incompatible with http, add support for
alpn names at the role struct, automatic generation of the
default list of alpn names that servers advertise, and the
ability to override the used alpn names per-vhost and per-
client connection.
This not only lets you modulate visibility or use of h2,
but also enables vhosts that only offer non-http roles,
as well as restricting http role vhosts to only alpn
identifiers related to http roles.
