It's perfectly possible we will have destroyed the wsi and report that
back in the return code. So let's not dumbly defreference the wsi to
make a log inbetweentimes.
Found with fault injection and valgrind.
In the case that we try ipv6 that isn't routable, we get a POLLHUP, that
marks the wsi as unusable (for writes, not pending reads), that's what
we want.
But in the case we go around and retry other dns results that are
routable, we have to clear the wsi unusable flag. Otherwise we will
connect and find that we can't write on the connection...
If the DNS lookup fails, we just sit out the remaining connect time.
The adapts it to reuse the wsi->sul_connect_timeout to schedule DNS lookup
retries until we're out of time.
Eventually we want to try other things as well, this is aligned with that.
Found with fault injection.
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.
For SMP case, it was desirable to have a netlink listener per pt so they
could deal with pt-level changes in the pt's local service thread. But
Linux restricts the process to just one netlink listener.
We worked around it by only listening on pt[0], this aligns us a bit more
with the reality and moves to a single routing table in the context.
There's still more to do for SMP case locking.
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.
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.
A few different places want to create wsis and basically repeat their
own versions of the flow. Let's unify it into one helper in wsi.c
Also require the context lock held (this only impacts LWS_MAX_SMP > 1)
If getaddrinfo() is not able to reach the server, there may be
a connectivity problem downstream of the device that has not
been recognized by the Captive Portal Detect pieces yet.
If it looks like that might have happened, used the getaddrinfo()
return to provoke a new CPD scan.
role ops are usually only sparsely filled, there are currently 20
function pointers but several roles only fill in two. No single
role has more than 14 of the ops. On a 32/64 bit build this part
of the ops struct takes a fixed 80 / 160 bytes then.
First reduce the type of the callback reason part from uint16_t to
uint8_t, this saves 12 bytes unconditionally.
Change to a separate function pointer array with a nybble index
array, it costs 10 bytes for the index and a pointer to the
separate array, for 32-bit the cost is
2 + (4 x ops_used)
and for 64-bit
6 + (8 x ops_used)
for 2 x ops_used it means 32-bit: 10 vs 80 / 64-bit: 22 vs 160
For a typical system with h1 (9), h2 (14), listen (2), netlink (2),
pipe (1), raw_skt (3), ws (12), == 43 ops_used out of 140, it means
the .rodata for this reduced from 32-bit: 560 -> 174 (386 byte
saving) and 64-bit: 1120 -> 350 (770 byte saving)
This doesn't account for the changed function ops calling code, two
ways were tried, a preprocessor macro and explicit functions
For an x86_64 gcc 10 build with most options, release mode,
.text + .rodata
before patch: 553282
accessor macro: 552714 (568 byte saving)
accessor functions: 553674 (392 bytes worse than without patch)
therefore we went with the macros
RFC6724 defines an ipv6-centric DNS result sorting algorithm, that
takes route and source address route information for the results
given by the DNS resolution, and sorts them in order of preferability,
which defines the order they should be tried in.
If LWS_WITH_NETLINK, then lws takes care about collecting and monitoring
the interface, route and source address information, and uses it to
perform the RFC6724 sorting to re-sort the DNS before trying to make
the connections.
This adds a helper to test if an sa46 is on an sa46-based subnet.
The compare helper is adapted to say that non INET/INET6 addresses with
the same AF match.
If we connect out to an IP address, or we adopt a connected socket,
from now on we want to hold the peer sockaddr in the wsi.
Adapt ACCESS_LOG to use this new copy rather than keep the
stringified version.
They have been in lib/roles/http for historical reasons, and all
ended up in client-handshake.c that doesn't describe what they
actually do any more. Separate out the staged client connect
related stage functions into
lib/core-net/client/client2.c: lws_client_connect_2_dnsreq()
lib/core-net/client/client3.c: lws_client_connect_3_connect()
lib/core-net/client/client4.c: lws_client_connect_4_established()
Move a couple of other functions from there that don't belong out to
tls-client.c and client-http.c, which is related to http and remains
in the http role dir.
