This commit is quite a substantial rework of the underlying layers in
BMP TX:
- several unnecessary layers of indirection dropped, including most of
the original BMP's buffer machinery
- all messages are now written directly into one protocol's buffer
allocated for the whole time big enough to fit every possible message
- output blocks are allocated by pages and immediately returned when
used, improving the overall memory footprint
- no intermediary allocation is done from the heap altogether
- there is a documented and configurable limit on the TX queue size
This reverts commit d01a7c2bda.
It seems that the performance penalty in global ea cache is actually
very high so returning back to local attribute caches in every BGP.
closes#86
The uncork events are running from mainloop so these should just
dispatch the right event to the right loop. Doing anything long there
is bad for performance and latency as the uncork list may be huge.
In future, this and rtable's data structures should be probably merged
but it isn't a good idea to do now. The used data structure is similar
to rtable -- an array of pointers to linked lists.
Feed is lockless, as with all tables.
Full export (receiving updates) is not supported yet but we don't have
any method how to use it anyway. Gonna implement it later.
There is no real need for storing bucket attributes locally and we may
save some memory by caching the attributes in one central place.
If this becomes a contention problem, we should reduce the lock load
of the central attribute cache.
Introducing a new omnipotent internal API to just pass route updates
from whatever point wherever we want.
From now on, all the exports should be processed by RT_WALK_EXPORTS
macro, and you can also issue a separate feed-only request to just get a
feed and finish.
The exporters can now also stop and the readers must expect that to
happen and recover. Main tables don't stop, though.
To avoid needs for keeping local temporary references for attributes,
now one can use ea_lookup_tmp() to ensure that the attributes are
valid and stored until the task ends. After that, the attributes are
automatically unref'd and also deallocated if needed.
Implement BGP Send hold timer according to draft-ietf-idr-bgp-sendholdtimer.
The Send hold timer drops the session if the neighbor is sending keepalives,
but does not receive our messages, causing the TCP connection to stall.
Some BGP capabilities change the BGP behavior in a significant way, so if
the configuration depends on it, it is better to not establish BGP
session when the capability is not available.
Add several BGP option to require individual BGP capabilities during
session negotiation.
Some [redacted] (yes, myself) had a really bad idea
to rename nest/route.h to nest/rt.h while refactoring
some data structures out of it.
This led to unnecessarily complex problems with
merging updates from v2. Reverting this change
to make my life a bit easier.
At least it needed only one find-sed command:
find -name '*.[chlY]' -type f -exec sed -i 's#nest/rt.h#nest/route.h#' '{}' +
This merge was particularly difficult. I finally resorted to delete the
symbol scope active flag altogether and replace its usage by other
means.
Also I had to update custom route attribute registration to fit
both the scope updates in v2 and the data model in v3.
Add internal BMP functions with plicit bmp_proto *p as first argument,
which allows using TRACE() macro. Keep list of BMP instances and call
internal functions. Old BMP functions are wrappers that call internal
functions for all enabled BMP instances.
Extract End-of-RIB mark into separate function.
Based on patch from Michal Zagorski <mzagorsk@akamai.com>. Thanks!
