This patch adapts the recent change about serializing the number of
simultaneous tls handshakes allowed to 1, so you can set the number in the
context creation info, and the accounting for it is handled by counters
same as the overally tls restriction.
The name of the context info var to control it changes to simultaneous_ssl_handshake_restriction
which is now a count, the default 0 means no limit.
The count rejects tls connection attempts when the tls borrow is attempted,
and separately hands back the hs borrow from the tls borrow when the
connection attempt fails or succeeds.
lws_tls_restrict_borrow() returns error when tls restriction limit is
reached. However lws_ssl_close() still calls lws_tls_restrict_return()
to decrease simultaneous_ssl. Thus LWS accepts more than allowed ssl
links, making simultaneous_ssl_restriction useless.
Fix it by tracking lws_tls_restrict_borrow() return value and only
calling lws_tls_restrict_return() if lws_tls_restrict_borrow() is
successful.
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.
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.
Currently we always reserve a fakewsi per pt so events that don't have a related actual
wsi, like vhost-protocol-init or vhost cert init via protocol callback can make callbacks
that look reasonable to user protocol handler code expecting a valid wsi every time.
This patch splits out stuff that user callbacks often unconditionally expect to be in
a wsi, like context pointer, vhost pointer etc into a substructure, which is composed
into struct lws at the top of it. Internal references (struct lws is opaque, so there
are only internal references) are all updated to go via the substructre, the compiler
should make that a NOP.
Helpers are added when fakewsi is used and referenced.
If not PLAT_FREERTOS, we continue to provide a full fakewsi in the pt as before,
although the helpers improve consistency by zeroing down the substructure. There is
a huge amount of user code out there over the last 10 years that did not always have
the minimal examples to follow, some of it does some unexpected things.
If it is PLAT_FREERTOS, that is a newer thing in lws and users have the benefit of
being able to follow the minimal examples' approach. For PLAT_FREERTOS we don't
reserve the fakewsi in the pt any more, saving around 800 bytes. The helpers then
create a struct lws_a (the substructure) on the stack, zero it down (but it is only
like 4 pointers) and prepare it with whatever we know like the context.
Then we cast it to a struct lws * and use it in the user protocol handler call.
In this case, the remainder of the struct lws is undefined. However the amount of
old protocol handlers that might touch things outside of the substructure in
PLAT_FREERTOS is very limited compared to legacy lws user code and the saving is
significant on constrained devices.
User handlers should not be touching everything in a wsi every time anyway, there
are several cases where there is no valid wsi to do the call with. Dereference of
things outside the substructure should only happen when the callback reason shows
there is a valid wsi bound to the activity (as in all the minimal examples).
Adapt the pt sul owner list to be an array, and define two different lists,
one that acts like before and is the default for existing users, and another
that has the ability to cooperate with systemwide suspend to restrict the
interval spent suspended so that it will wake in time for the earliest
thing on this wake-suspend sul list.
Clean the api a bit and add lws_sul_cancel() that only needs the sul as the
argument.
Add a flag for client creation info to indicate that this client connection
is important enough that, eg, validity checking it to detect silently dead
connections should go on the wake-suspend sul list. That flag is exposed in
secure streams policy so it can be added to a streamtype with
"swake_validity": true
Deprecate out the old vhost timer stuff that predates sul. Add a flag
LWS_WITH_DEPRECATED_THINGS in cmake so users can get it back temporarily
before it will be removed in a v4.2.
Adapt all remaining in-tree users of it to use explicit suls.
Remove LWS_LATENCY.
Add the option LWS_WITH_DETAILED_LATENCY, allowing lws to collect very detailed
information on every read and write, and allow the user code to provide
a callback to process events.
wsi timeout, wsi hrtimer, sequencer timeout and vh-protocol timer
all now participate on a single sorted us list.
The whole idea of polling wakes is thrown out, poll waits ignore the
timeout field and always use infinite timeouts.
Introduce a public api that can schedule its own callback from the event
loop with us resolution (usually ms is all the platform can do).
Upgrade timeouts and sequencer timeouts to also be able to use us resolution.
Introduce a prepared fakewsi in the pt, so we don't have to allocate
one on the heap when we need it.
Directly handle vh-protocol timer if LWS_MAX_SMP == 1
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).
This changes the vhost destroy flow to only hand off the listen
socket if another vhost sharing it, and mark the vhost as
being_destroyed.
Each tsi calls lws_check_deferred_free() once a second, if it sees
any vhost being_destroyed there, it closes all wsi on its tsi on
the same vhost, one time.
As the wsi on the vhost complete close (ie, after libuv async close
if on libuv event loop), they decrement a reference count for all
wsi open on the vhost. The tsi who closes the last one then
completes the destroy flow for the vhost itself... it's random
which tsi completes the vhost destroy but since there are no
wsi left on the vhost, and it holds the context lock, nothing
can conflict.
The advantage of this is that owning tsi do the close for wsi
that are bound to the vhost under destruction, at a time when
they are guaranteed to be idle for service, and they do it with
both vhost and context locks owned, so no other service thread
can conflict for stuff protected by those either.
For the situation the user code may have allocations attached to
the vhost, this adds args to lws_vhost_destroy() to allow destroying
the user allocations just before the vhost is freed.
Several new ops are planned for tls... so better to bite the bullet and
clean it out to the same level as roles + event-libs first.
Also adds a new travis target "mbedtls" and all the tests except
autobahn against mbedtls build.
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.
