Several changes and bugfixes in Babel, namely:
- Exported route parameters stored directly in route table entry
- Exported non-babel routes no longer stored in per-entry route list
- Route update, selection and retraction simplified and fixed
- Route feasibility is evalualated per update and stored with route
- Unreachable route handling fixed, based on hold interval
- Added 'show babel routes' command
Overall, it fixes some issues with proper propagation of triggered
updates, making Babel convergence after topology change almost
instant.
The subtlv parsing code was doing byte-based arithmetic with non-void pointers,
causing it to read beyond the end of the packet.
Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
RFC6126bis formally introduces sub-TLVs to the Babel protocol, including
mandatory sub-TLVs. This adds support for parsing sub-TLVs to the Babel
protocol and skips TLVs that contain mandatory sub-TLVs, as per the spec.
For details, see section 4.4 of
https://tools.ietf.org/html/draft-ietf-babel-rfc6126bis-02
Thanks to Toke Høiland-Jørgensen <toke@toke.dk> for the patch.
Previously, the Babel protocol would never use prefix compression on outgoing
updates (but would parse it on incoming ones). This adds compression of IPv6
addresses of outgoing updates.
The compression only works to the extent that the FIB is walked in lexicographic
order; i.e. a prefix is only compressed if it shares bytes with the previous
prefix in the same packet.
Thanks to Toke Høiland-Jørgensen <toke@toke.dk> for the patch.
This adds support for dual-stack v4/v6 operation to the Babel protocol.
Routing messages will be exchanged over IPv6, but IPv4 routes can be
carried in the messages being exchanged. This matches how the reference
Babel implementation (babeld) works.
The nexthop address for v4 can be configured per interface, and will
default to the first available IPv4 address on the given interface. For
symmetry, a configuration option to configure the IPv6 nexthop address
is also added.
Thanks to Toke Høiland-Jørgensen <toke@toke.dk> for the patch.
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 patch implements the IPv6 subset of the Babel routing protocol.
Based on the patch from Toke Hoiland-Jorgensen, with some heavy
modifications and bugfixes.
Thanks to Toke Hoiland-Jorgensen for the original patch.
