Add a new route attribute, krt_scope, to expose the Linux kernel route
scope. Constants from /etc/iproute2/rt_scopes (prefixed by "ips_") are
expected to be used with the attribute. Both import and export are
supported.
Also, the patch fixes device route export to the kernel, by setting link
scope automatically.
It is possible that sockets_add() are called between sockets_prepare()
and sockets_fire() during poll loop in birdloop_main(), so we need to
use loop->poll_fd.used instead of loop->sock_num to find the last field.
Kernel protocol calls rt_export_merged(), which used @rte_update_pool for
temporary allocations, supposing it is called from other functions from
rt-table.c that handles locking and flushing of the linpool. Therefore,
linpool was not flushed properly and memory leaked.
Add linpool argument to rt_export_merged() and use @krt_filter_lp when
called from kernel protocol.
Thanks to Justin Cattle and Alexander Frolkin for the bugreport.
(Commit squashed and updated by Ondrej Zajicek)
Kernel routes with different metrics do not clash with each other,
therefore using dedicated metric value is a reliable way to avoid
overwriting routes from other sources (e.g. kernel device routes).
Although kernel route metric could already be set as a route attribute by
filters, that is not consistent with the way how Linux kernel handles
route metric - not just a route attribute, but a part of a route key.
Linux represents IPv6 ECMP routes as a sequence of unipath routes with
the same prefix. We have to translate between our representation (one
route with multipath next hop) and the Linux representation in both
directions.
Proper learning of alien IPv6 ECMP routes still not supported.
Thanks to Mikhail Sennikovskii for the original patch.
An interface reconfiguration may change both the hello and update
intervals. An update interval change is immediately put into effect,
while a hello interval change is not. This also updates the hello
interval immediately (if the new interval is shorter than the old one),
and sends a hello to notify peers of the change.
Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
Ignore tentative IPv6 addresses and wait until finish of Duplicate
Address Detection (We got notification when an address is no longer
tentative) to avoid problems when protocols try to use interfaces
with tentative link-local addresses.
Based on patch from Jan Moskyto Matejka
We do not need to maintain feasibility distances for our own router
ID (we ignore the updates anyway). Not doing so makes the routes be
garbage collected sooner when export filters change.
Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
When a route becomes infeasible it should not be kept as selected; this
is forbidden by section 3.6 of the RFC and prevents subsequent updates
from the same router ID from replacing it.
Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
This makes BIRD send a wildcard retraction on all interfaces before
shutting down and right after starting up. This helps ensure that
neighbours will discard the announced routes as soon as possible,
rather than only after the normal timeout procedures.
Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
An update with wildcard AE and infinite metric should be treated as a
global retraction of all prefixes announced by that neighbour, per
section 4.4.9 of the RFC. In addition, router ID and seqno in retraction
updates should be ignored. This reworks the handling of retractions and
adjusts the parser to handle all this correctly.
Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
This updates the documentation to correctly mention Babel when protocols
are listed, and adds examples and route attribute documentation to the
Babel section of the docs.
Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
Intervals are carried as 16-bit centisecond values, but kept internally
in 16-bit second values, which causes a potential for overflow. This adds
some checks to make sure this does not happen.
Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
Although RFC 4271 does not forbid empty path segments, they are useless
and some implementations consider them invalid. It is clarified in RFC 7606,
specifying that AS_PATH with empty segment is considered malformed.
