The nest-protocol interaction is changed to better handle multitable
protocols. Multitable protocols now declare that by 'multitable' field,
which tells nest that a protocol handles things related to proto-rtable
interaction (table locking, announce hook adding, reconfiguration of
filters) itself.
Filters and stats are moved to announce hooks, a protocol could have
different filters and stats to different tables.
The patch is based on one from Alexander V. Chernikov, thanks.
Hostcache is a structure for monitoring changes in a routing table that
is used for routes with dynamic/recursive next hops. This is needed for
proper iBGP next hop handling.
- BSD kernel syncer is now self-conscious and can learn alien routes
- important bugfix in BSD kernel syncer (crash after protocol restart)
- many minor changes and bugfixes in kernel syncers and neighbor cache
- direct protocol does not generate host and link local routes
- min_scope check is removed, all routes have SCOPE_UNIVERSE by default
- also fixes some remaining compiler warnings
It seems that by adding one pipe-specific exception to route
announcement code and by adding one argument to rt_notify() callback i
could completely eliminate the need for the phantom protocol instance
and therefore make the code more straightforward. It will also fix some
minor bugs (like ignoring debug flag changes from the command line).
Process well-known communities before the export filter (old behavior is
to process these attributes after, which does not allow to send route
with such community) and just for routes received from other BGP
protocols. Also fixes a bug in next_hop check.
There is no reak callback scheduler and previous behavior causes
bad things during hard congestion (like BGP hold timeouts).
Smart callback scheduler is still missing, but main loop was
changed such that it first processes all tx callbacks (which
are fast enough) (but max 4* per socket) + rx callbacks for CLI,
and in the second phase it processes one rx callback per
socket up to four sockets (as rx callback can be slow when
there are too many protocols, because route redistribution
is done synchronously inside rx callback). If there is event
callback ready, second phase is skipped in 90% of iterations
(to speed up CLI during congestion).
Although standard says that if we receive AS_PATH_CONFED_*
(and we are not a part of a confederation) segment, we should
drop session, nobody does that and it is unwise to do that.
Now we drop session just in case that peer ASN is in
AS_PATH_CONFED_* segment (to detect peer that considers BIRD
as a part of its confederation).
AS4 optional attribute errors were handled by session
drop (according to BGP RFC). This patch implements
error handling according to new BGP AS4 draft (*)
- ignoring invalid AS4 optional attributes.
(*) http://www.ietf.org/internet-drafts/draft-chen-rfc4893bis-02.txt
This patch extends the length for attributes from 1024 to 2048
(because both AS_PATH and AS4_PATH attributes take 2+4 B per AS).
If there is not enough space for attributes, Bird skips that
route group. Old behavior (skipping remaining attributes)
leads to skipping required attributes and session drop.
When capability related error is received, next connect will be
without capabilities. Also cease error subcodes descriptions
(according to [RFC4486]) are added.
BGP keeps its copy of configuration ptr and didn't update it during
reconfiguration. But old configuration is freed during reconfiguration.
That leads to unnecessary reset of BGP connection during reconfiguration
(old conf is corrupted and therefore different) and possibly other strange
behavior.
Fixes two race conditions causing crash of Bird, several unhandled
cases during BGP initialization, and some other bugs. Also changes
handling of startup delay to be more useful and implement
reporting of last error in 'show protocols' command.
RFC says that only connections in OpenConfirm and Established state
should participate in connection collision detection.
The current implementation leads to race condition when both sides
are trying to connect at the almost same time, then both sides
receive OPEN message by different connections at the almost same
time and close the other connection. Both connections are
closed and the both sides end in start/idle or start/active
state.
