When using multiple client contextes in a single application, rops_pt_init_destroy_netlink() fails binding the second socket and on - only the first one succeeds. The failure is made obvious by this log:
W: rops_pt_init_destroy_netlink: netlink bind failed
So, let's fix this by doing what netlink(7) man page suggests:
If the application sets nl_pid before calling bind(2), then it is up to the
application to make sure that nl_pid is unique. If the application sets it
to 0, the kernel takes care of assigning it. The kernel assigns the process
ID to the first netlink socket the process opens and assigns a unique nl_pid
to every netlink socket that the process subsequently creates.
NEWADDR was errantly deleting route entities, specifically it happend
to delete IPv6 route entries causing a disconnect of all IPv6 clients.
NEWADDR can be issued on a DHCP lease renew, which does not change any
of the routes.
Code was also cleaned up a bit, and added some helpful logging.
this patch makes ubsan (-fsanitize-undefined-trap-on-error) happy.
let's look at the following scenario:
1. netlink sends RTM_NEWADDR/RTM_DELADDR message
2. rops_handle_POLLIN_netlink() handles message attributes as RTA_*
3. rops_handle_POLLIN_netlink() finds RTA_PRIORITY attribute and
handles it as u32 value, but it's IFA_CACHEINFO attribute in reality
and payload holds another type
4. ubsan throws SIGTRAP
so, don't handle RTM_NEWADDR/RTM_DELADDR attributes as RTA_*
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.
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)
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
This creates a role for RFC3549 Netlink monitoring.
If the OS supports it (currently, linux) then each pt creates a wsi
with the netlink role and dumps the current routing table at pt init.
It then maintains a cache of the routing table in each pt.
Upon routing table changes an SMD message is issued as an event, and
Captive Portal Detection is triggered.
All of the pt's current connections are reassessed for routability under
the changed routing table, those that no longer have a valid route or
gateway are closed.
