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.
Add a member to the vh init struct allowing control of the overall
connection wait introduced in an earlier patch. Set it to 20s
by default.
The timeout_secs member controls the individual DNS result
connect timeout and is reduced to 5s by default.
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.
Adds client support for MQTT QoS0 and QoS1, compatible with AWS IoT
Supports stream binding where independent client connections to the
same endpoint can mux on a single tcp + tls connection with topic
routing managed internally.
This adds support for POST in both h1 and h2 queues / stream binding.
The previous queueing tried to keep the "leader" wsi who made the
actual connection around and have it act on the transaction queue
tail if it had done its own thing.
This refactors it so instead, who is the "leader" moves down the
queue and the queued guys inherit the fd, SSL * and queue from the
old leader as they take over.
This lets them operate in their own wsi identity directly and gets
rid of all the "effective wsi" checks, which was applied incompletely
and getting out of hand considering the separate lws_mux checks for
h2 and other muxed protocols alongside it.
This change also allows one wsi at a time to own the transaction for
POST. --post is added as an option to lws-minimal-http-client-multi
and 6 extra selftests with POST on h1/h2, pipelined or not and
staggered or not are added to the CI.
Add selectable event lib support to minimal-http-client-multi and
clean up context destroy flow so we can use lws_destroy_context() from
inside the callback to indicate we want to end the event loop, without
using the traditional "interrupted" flag and in a way that works no
matter which event loop backend is being used.
Freertos + lwip doesn't support pipe2() or pipe()... implement a "pipe"
based on two UDP sockets, one listening on 127.0.0.1:54321 and the other
doing a sendto() there of a single byte to interrupt the event loop wait.
Re-use the arrangements for actual pipe fds and pipe role to deliver
lws_cancel_service() functionality using this.
Saw this on travis selftests during context destroy
==18895== Invalid read of size 8
==18895== at 0x415909: __lws_vhost_destroy2 (vhost.c:1063)
==18895== by 0x40E65B: lws_context_destroy2 (context.c:929)
==18895== by 0x40EBE5: lws_context_destroy (context.c:1128)
==18895== by 0x40CC41: main (minimal-http-client-post.c:267)
==18895== Address 0x6168688 is 728 bytes inside a block of size 792 free'd
==18895== at 0x4C2BDEC: free (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==18895== by 0x45B29E: _realloc (alloc.c:120)
==18895== by 0x45B2D6: lws_realloc (alloc.c:130)
==18895== by 0x415ED7: __lws_vhost_destroy2 (vhost.c:1204)
==18895== by 0x419164: lws_vhost_unbind_wsi (wsi.c:82)
==18895== by 0x41236B: __lws_free_wsi (close.c:154)
==18895== by 0x4134CF: __lws_close_free_wsi_final (close.c:650)
==18895== by 0x4133BA: __lws_close_free_wsi (close.c:610)
==18895== by 0x413528: lws_close_free_wsi (close.c:660)
==18895== by 0x4158C7: __lws_vhost_destroy2 (vhost.c:1053)
==18895== by 0x40E65B: lws_context_destroy2 (context.c:929)
==18895== by 0x40EBE5: lws_context_destroy (context.c:1128)
Removing the last wsi from the vhost we started to destroy finalized the
vhost destruction, which is aimed at libuv async close cleanup. But if
we already entered __lws_vhost_destroy2, we will definitely destroy the vhost
ourselves at the end of that function already. So defeat the wsi close
triggering it.
h1 and h2 has a bunch of code supporting autobinding outgoing client connections
to be streams in, or queued as pipelined on, the same / existing single network
connection, if it's to the same endpoint.
Adapt this http-specific code and active connection tracking to be usable for
generic muxable protocols the same way.
Introduce a generic lws_state object with notification handlers
that may be registered in a chain.
Implement one of those in the context to manage the "system state".
Allow other pieces of lws and user code to register notification
handlers on a context list. Handlers can object to or take over
responsibility to move forward and retry system state changes if
they know that some dependent action must succeed first.
For example if the system time is invalid, we cannot move on to
a state where anything can do tls until that has been corrected.
Refactor everything around ping / pong handling in ws and h2, so there
is instead a protocol-independent validity lws_sul tracking how long it
has been since the last exchange that confirms the operation of the
network connection in both directions.
Clean out periodic role callback and replace the last two role users
with discrete lws_sul for each pt.
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.
This adds the option to have lws do its own dns resolution on
the event loop, without blocking. Existing implementations get
the name resolution done by the libc, which is blocking. In
the case you are opening client connections but need to carefully
manage latency, another connection opening and doing the name
resolution becomes a big problem.
Currently it supports
- ipv4 / A records
- ipv6 / AAAA records
- ipv4-over-ipv6 ::ffff:1.2.3.4 A record promotion for ipv6
- only one server supported over UDP :53
- nameserver discovery on linux, windows, freertos
It also has some nice advantages
- lws-style paranoid response parsing
- random unique tid generation to increase difficulty of poisoning
- it's really integrated with the lws event loop, it does not spawn
threads or use the libc resolver, and of course no blocking at all
- platform-specific server address capturing (from /etc/resolv.conf
on linux, windows apis on windows)
- it has LRU caching
- piggybacking (multiple requests before the first completes go on
a list on the first request, not spawn multiple requests)
- observes TTL in cache
- TTL and timeout use lws_sul timers on the event loop
- ipv6 pieces only built if cmake LWS_IPV6 enabled
lws_dll2 removes the downsides of lws_dll and adds new features like a
running member count and explicit owner type... it's cleaner and more
robust (eg, nodes know their owner, so they can casually switch between
list owners and remove themselves without the code knowing the owner).
This deprecates lws_dll, but since it's public it allows it to continue
to be built for 4.0 release if you give cmake LWS_WITH_DEPRECATED_LWS_DLL.
All remaining internal users of lws_dll are migrated to lws_dll2.
