This commit makes the route chains in the tables atomic. This allows not
only standard exports but also feeds and bulk exports to be processed
without ever locking the table.
Design note: the overall data structures are quite brittle. We're using
RCU read-locks to keep track about readers, and we're indicating ongoing
work on the data structures by prepending a REF_OBSOLETE sentinel node
to make every reader go waiting.
All the operations are intended to stay inside nest/rt-table.c and it
may be even best to further refactor the code to hide the routing table
internal structure inside there. Nobody shall definitely write any
routines manipulating live routes in tables from outside.
BGP route attributes have flags (Optional, Transitive) that are validated
on decode and set to valid value on export. But if such attribute is
modified by filter or set internally by BGP during import, then its flags
would be zero in local tables. That usually does not matter, as they are
not used locally and they were fixed on export, but invalid flags leaked
in BMP and MRT dumps.
Keep route attribute flags set to valid values even when set by filters
or modified by BGP.
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.
When MPLS is active, received routes on MPLS-aware SAFIs (ipvX-mpls,
vpnX-mpls) are automatically labeled according to active label policy and
corresponding MPLS routes are automatically generated. Also routes sent
on MPLS-aware SAFIs announce local labels when it should be done.
Memory allocation is a fragile part of BIRD and we need checking that
everybody is using the resource pools in an appropriate way. To assure
this, all the resource pools are associated with locking domains and
every resource manipulation is thoroughly checked whether the
appropriate locking domain is locked.
With transitive resource manipulation like resource dumping or mass free
operations, domains are locked and unlocked on the go, thus we require
pool domains to have higher order than their parent to allow for this
transitive operations.
Adding pool locking revealed some cases of insecure memory manipulation
and this commit fixes that as well.
Initial implementation of a basic subset of the BMP (BGP Monitoring
Protocol, RFC 7854) from Akamai team. Submitted for further review
and improvement.
This brought unnecessary complexity into the decision procedures while the
performance aspects weren't worth it. It just saved one ea_list traversal
when many others are also done.
In principle, the channel list is a list of parent struct proto and can
contain general structures of type struct channel, That is useful e.g.
for adding MPLS channels to BGP.
Had to fix route source locking inside BGP export table as we need to
keep the route sources properly allocated until even last BGP pending
update is sent out, therefore the export table printout is accurate.
There were more conflicts that I'd like to see, most notably in route
export. If a bisect identifies this commit with something related, it
may be simply true that this commit introduces that bug. Let's hope it
doesn't happen.
The invalid routes were filtered out before they could ever get
exported, yet some of the routines need them available, e.g. for
display or import reload.
Now the invalid routes are properly exported and dropped in channel
export routines instead.
