There are a few build options that are trying to keep and report
various statistics
- DETAILED_LATENCY
- SERVER_STATUS
- WITH_STATS
remove all those and establish a generic rplacement, lws_metrics.
lws_metrics makes its stats available via an lws_system ops function
pointer that the user code can set.
Openmetrics export is supported, for, eg, prometheus scraping.
If the client library loses the proxy connection, it can receive
an endless stream of 0 length rx instead of understanding that
the UDS peer has gone.
Handle that correctly so the client reacts to the loss of the
proxy link by trying to reacquire it.
Adapt the sspc state to be suitable for retry in that case,
by dropping any dsh and letting the logical ss know that he
is DISCONNECTED, if he thought he was CONNECTED.
The state tracking and violation detection is very powerful at enforcing
only legal transitions, but if it's busy, we don't get to see which stream
had to problem. Add a pointer to the handle lc tag, do that rather than
just pass the handle so we can deal with ss and sspc handles cleanly.
Add .proxy_buflen_rxflow_on_above / .proxy_buflen_rxflow_off_below policy streamtype options
and manage the rx flow control for the onward ss wsi according to how the dsh for the
remote client is doing.
client_buflen_rxflow_... are there but not wired up.
The various stream transitions for direct ss, SSPC, smd, and
different protocols are all handled in different code, let's
stop hoping for the best and add a state transition validation
function that is used everywhere we pass a state change to a
user callback, and knows what is valid for the user state()
callback to see next, given the last state it was shown.
Let's assert if lws manages to violate that so we can find
where the problem is and provide a stricter guarantee about
what user state handler will see, no matter if ss or sspc
or other cases.
To facilitate that, move the states to start from 1, where
0 indicates the state unset.
Let's allow the proxy to pass back what the policy says about
the size of dsh buffer the client side of this streamtype
should have.
Defer clientsize dsh generation until we got the info back
from the proxy in the response to the initial packet. If
it's zero / unset in the policy, just go with 32KB.
Let's add a byte on the first message that sspc clients send,
indicating the version of the serialization protocol that the
client was built with.
Start the version at 1, we will add some more changes in other
patches and call v1 (now it has the versioning baked in)
the first real supported serialization version, this patch must
be applied with the next patches to actually represent v1
protocol changes.
This doesn't require user setting, the client is told what version
it supports in LWS_SSS_CLIENT_PROTOCOL_VERSION. The proxy knows
what version(s) it can support and loudly hangs up on the client
if it doesn't understand its protocol version.
Add a helper to simplify passing smd ss rx traffic into the local
smd participants, excluding the rx that received it externally to
avoid looping.
Make the smd readme clearer with three diagrams and more explanation
of how the ss proxying works.
This is a huge patch that should be a global NOP.
For unix type platforms it enables -Wconversion to issue warnings (-> error)
for all automatic casts that seem less than ideal but are normally concealed
by the toolchain.
This is things like passing an int to a size_t argument. Once enabled, I
went through all args on my default build (which build most things) and
tried to make the removed default cast explicit.
With that approach it neither change nor bloat the code, since it compiles
to whatever it was doing before, just with the casts made explicit... in a
few cases I changed some length args from int to size_t but largely left
the causes alone.
From now on, new code that is relying on less than ideal casting
will complain and nudge me to improve it by warnings.
This adds some new objects and helpers for keeping and logging
info on grouped allocations, a group is, eg, SS handles or client
wsis.
Allocated objects get a context-unique "tag" string intended to replace
%p / wsi pointers etc. Pointers quickly become confusing when
allocations are freed and reused, the tag string won't repeat
until you produce 2^64 objects in a context.
In addition the tag string documents the object group, with prefixes
like "wsi-" or "vh-" and contain object-specific additional
information like the vhost name, address / port or the role of the wsi.
At creation time the lws code can use a format string and args
to add whatever group-specific info makes sense, eg, a wsi bound
to a secure stream can also append the guid of the secure stream,
it's copied into the new object tag and so is still available
cleanly after the stream is destroyed if the wsi outlives it.
For LWSSSCS_UNREACHABLE state, the additional ord arg has b0 set if the
reason for the unreachability is because the DNS server itself was not
reachable (implying either DNS server is wrongly set, or is not reachable
due to not having connectivity through to it)
Since client_connect and request_tx can be called from code that expects
the ss handle to be in scope, these calls can't deal with destroying the
ss handle and must pass the lws_ss_state_return_t disposition back to
the caller to handle.
