Generic lws_system IPv4 DHCP client
- netif and route control via lib/plat apis
- linux plat pieces implemented
- Uses raw ip socket for UDP broadcast and rx
- security-aware
- usual stuff plus up to 4 x dns server
If it's enabled for build, it holds the system
state at DHCP until at least one registered interface
has acquired a set of IP / mask / router / DNS server
It uses PF_PACKET which is Linux-only atm. But those
areas are isolated into plat code.
TODOs
- lease timing and reacquire
- plat pieces for other than Linux
Move libev workaround outside the
if ((LWS_ROLE_H1 OR LWS_ROLE_H2) AND NOT LWS_WITHOUT_TESTAPPS) block
otherwise build fails on:
/home/naourr/work/instance-1/output-1/build/libwebsockets-3.2.0/lib/event-libs/libev/libev.c: In function 'lws_ev_hrtimer_cb':
/home/naourr/work/instance-1/output-1/build/libwebsockets-3.2.0/lib/event-libs/libev/libev.c:34:3: error: dereferencing type-punned pointer will break strict-aliasing rules [-Werror=strict-aliasing]
ev_timer_set(&pt->ev.hrtimer, ((float)us) / 1000000.0, 0);
^~~~~~~~~~~~
Fixes:
- http://autobuild.buildroot.org/results/b5a2188dce90f3ca9bf0cc7a043c1a946b8e288f
AG: this doesn't really fix anything... the spew is intentionally part of libev.
It just hides the spew... since the maintainer won't fix it
this is the only way AFAIK. Other than don't use libev.
Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
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.
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
Improve the code around stash, getting rid of the strdups for a net
code reduction. Remove the special destroy helper for stash since
it becomes a one-liner.
Trade several stack allocs in the client reset function for a single
sized brief heap alloc to reduce peak stack alloc by around 700 bytes.
External poll support generates a lot of messages on a busy system
for no value unless you're one of the few people using it. It's
not recommended for new users and is there for backwards compatibility.
Make it not built by default and selectable by cmake option.
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
There are quite a few linked-lists of things that want events after
some period. This introduces a type binding an lws_dll2 for the
list and a lws_usec_t for the duration.
The wsi timeouts, the hrtimer and the sequencer timeouts are converted
to use these, also in the common event wait calculation.
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.
Adapt service loops and event libs to use microsecond waits
internally, for hrtimer and sequencer. Reduce granularity
according to platform / event lib wait.
Add a helper so there's a single place to extend it.
Rewrite HMAC stuff to use HMAC_ apis instead of EVP
Bit trickly since modern OpenSSL has opaque HMAC_CTX and older
OpenSSL does not have any apis to allocate and free it.
Add another cmake check for the allocation api to decide
what to do.
Building with LWS_WITH_ASAN was broken when using Clang, due to some
flags being given that Clang doesn't recognize.
Fixed this by adding those flags only when the compiler isn't Clang.
The fix in 1d6128d1fe worked for
MinGW with GCC7, but GCC8 evidentially got smarter, and it
also substitutes bzero->memset for larger arrays.
Set the emitted warning as an error to avoid misdetection.
Using a C compiler ignores non-existent functions, and tries to link them anyway.
The compiler optimizes `bzero(buf, 1)` to `movb $0x0,0xf(%esp)`, so bzero is
not called at all, and the linker succeeds.
Increase the buffer size to 100 to avoid this optimization.
