Despite not having defined 'master interface', VRF interfaces should be
treated as being inside respective VRFs. They behave as a loopback for
respective VRFs. Treating the VRF interface as inside the VRF allows
e.g. OSPF to pick up IP addresses defined on the VRF interface.
For this, we also need to tell apart VRF interfaces and regular interfaces.
Extend Netlink code to parse interface type and mark VRF interfaces with
IF_VRF flag.
Based on the patch from Erin Shepherd, thanks!
Move all bmp_peer_down() calls to one place and make it synchronous with
BGP session down, ensuring that BMP receives peer_down before route
withdraws from flushing.
Also refactor bmp_peer_down_() message generating code.
Now we use rt_notify() and channels for both feed and notifications,
in both import tables (pre-policy) and regular tables (post-policy).
Remove direct walk in bmp_route_monitor_snapshot().
- Manage BMP state through bmp_peer, bmp_stream, bmp_table structures
- Use channels and rt_notify() hook for route announcements
- Add support for post-policy monitoring
- Send End-of-RIB even when there is no routes
- Remove rte_update_in_notify() hook from import tables
- Update import tables to support channels
- Add bmp_hack (no feed / no flush) flag to channels
Currently one can use only a predefined set of advertised options in RAdv
protocol, which are supported by BIRD configuration. It would be convenient
to be able to specify other possible options at least manually as a blob
so one should not wait until it is supported in the code, released, etc.
This idea is inspired by presentation by Ondřej Caletka at CSNOG, in which
he noticed the lack of either PREF64 option or possibility to add custom
options in various software.
The patch makes it possible to define such options with the syntax:
other type <num> <bytestring>
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!
This adds support to the Babel protocol for the RTT extension specified
in draft-ietf-babel-rtt-extension. While this extension is not yet at the
RFC stage, it is one of the more useful extensions to Babel[0], so it
seems worth having in Bird as well.
The extension adds timestamps to Hello and IHU TLVs and uses these to
compute an RTT to each neighbour. An extra per-neighbour cost is then
computed from the RTT based on a minimum and maximum interval and cost
value specified in the configuration. The primary use case for this is
improving routing in a geographically distributed tunnel-based overlay
network.
The implementation follows the babeld implementation when picking
constants and default configuration values. It also uses the same RTT
smoothing algorithm as babeld, and follows it in adding a new 'tunnel'
interface type which enables RTT by default.
[0] https://alioth-lists.debian.net/pipermail/babel-users/2022-April/003932.html
Fix issue with missing AF cap (e.g. IPv4 unicast when no capabilities
are announced).
Add Linpool save/restore action similar to bgp_create_update().
Based on patch from Michal Zagorski <mzagorsk@akamai.com> co-authored
with Pawel Maslanka <pmaslank@akamai.com>. Thanks!
When an OPEN message without capability options was parsed, the remote
role field was not initialized with the proper (non-zero) default value,
so it was interpreted as if 'provider' was announced.
Thanks to Mikhail Grishin for the bugreport.
The BMP protocol needs OPEN messages of established BGP sessions to
construct appropriate Peer Up messages. Instead of saving them internally
we use OPEN messages stored in BGP instances. This allows BMP instances
to be restarted or enabled later.
Because of this change, we can simplify BMP data structures. No need to
keep track of BGP sessions when we are not started. We have to iterate
over all (established) BGP sessions when the BMP session is established.
This is just a scaffolding now, but some kind of iteration would be
necessary anyway.
Also, the commit cleans up handling of msg/msg_length arguments to be
body/body_length consistently in both rx/tx and peer_up/peer_down calls.
For whatever reason, parser allocated a symbol for every parsed keyword
in each scope. That wasted time and memory. The effect is worsened with
recent changes allowing local scopes, so keywords often promote soft
scopes (with no symbols) to real scopes.
Do not allocate a symbol for a keyword. Take care of keywords that could
be promoted to symbols (kw_sym) and do it explicitly.
Hooks called from BGP to BMP should not log warning when BMP is not
connected, that is not an error (and we do not want to flood logs with
a ton of messages).
Blocked sk_send() should not log warning, that is expected situation.
Error during sk_send() is handled in error hook anyway.
Replace broken TCP connection management with a simple state machine.
Handle failed attempts properly with a timeout, detect and handle TCP
connection close and try to reconnect after that. Remove useless
'station_connected' flag.
Keep open messages saved even after the BMP session establishment,
so they can be used after BMP session flaps.
Use proper log messages for session events.
Use local variable to refence relevant instance instead of using global
instance ptr. Also, use 'p' variable instead of 'bmp' so we can use
common macros like TRACE().
Most error handling code was was for cases that cannot happen,
or they would be code bugs (and should use ASSERT()). Keep error
handling for just for I/O errors, like in rest of BIRD.
Initial implementation of a basic subset of the BMP (BGP Monitoring
Protocol, RFC 7854) from Akamai team. Submitted for further review
and improvement.
Missing translation from BGP attribute ID to eattr ID in bgp_unset_attr()
broke automatic removal of bgp_med during export to EBGP peers.
Thanks to Edward Sun for the bugreport.
Even though the free bind option is primarily meant to alleviate problems
with addresses assigned too late, it's also possible to use BIRD with AnyIP
configuration, assigning whole ranges to the machine. Therefore free bind
allows also to create an outbound connection from specific address even though
such address is not assigned.
The babel protocol normally sends all its messages as multicast packets,
but the protocol specification allows most messages to be sent as either
unicast or multicast, and the two can be mixed freely. In particular, the
babeld implementation can be configured to unicast updates to all peers
instead of sending them as unicast.
Daniel discovered that this can cause problems with the packet counter
checks in the MAC extension due to packet reordering. This happens on WiFi
networks where clients have power save enabled (which is quite common in
infrastructure networks): in this case, the access point will buffer all
multicast traffic and only send it out along with its beacons, leading to a
maximum buffering in default Linux-based access point configuration of up
to 200 ms.
This means that a Babel sender that mixes unicast and multicast messages
can have the unicast messages overtake the multicast messages because of
this buffering; when authentication is enabled, this causes the receiver to
discard the multicast message when it does arrive because it now has a
packet counter value less than the unicast message that arrived before it.
Daniel observed that this happens frequently enough that Babel ceases to
work entirely when runner over a WiFi network.
The issue has been described in draft-ietf-babel-mac-relaxed, which is
currently pending RFC publication. That also describes two mitigation
mechanisms: Keeping separate PC counters for unicast and multicast, and
using a reorder window for PC values. This patch implements the former as
that is the simplest, and resolves the particular issue seen on WiFi.
Thanks to Daniel Gröber for the bugreport.
Minor changes from committer.
The patch implements an IPv4 via IPv6 extension (RFC 9229) to the Babel
routing protocol (RFC 8966) that allows annoncing routes to an IPv4
prefix with an IPv6 next hop, which makes it possible for IPv4 traffic
to flow through interfaces that have not been assigned an IPv4 address.
The implementation is compatible with the current Babeld version.
Thanks to Toke Høiland-Jørgensen for early review on this work.
Minor changes from committer.
When creating a new babel_source object we initialise the seqno to 0. The
caller will update the source object with the right metric and seqno value,
for both newly created and old source objects. However if we initialise the
source object seqno to 0 that may actually turn out to be a valid (higher)
seqno than the one in the routing table, because of seqno wrapping. In this
case the source metric will not be set properly, which breaks feasibility
tracking for subsequent updates.
To fix this, add a new initial_seqno argument to babel_get_source() which
is used when allocating a new object, and set that to the seqno value of
the update we're sending.
Thanks to Juliusz Chroboczek for the bugreport.
Juliusz noticed there were a couple of places we were doing straight
inequality comparisons of seqnos in Babel. This is wrong because seqnos can
wrap: so we need to use the modulo-64k comparison function for these cases
as well.
Introduce a strict-inequality version of the modulo-comparison for this
purpose.
For active sessions, ignore received packets with zero local id and
mismatched remote id. That forces a session timeout instead of an
immediate session restart. It makes BFD sessions more resilient to
packet spoofing.
Thanks to André Grüneberg for the suggestion.
