Even if we have unnumbered peering, let's respect `no neighbor X capability link-local`
and disable it per-neighbor on demand.
Fixes: db853cc97e ("bgpd: Implement Link-Local Next Hop capability")
Signed-off-by: Donatas Abraitis <donatas@opensourcerouting.org>
If we have LL Next Hop capability exchanged, we should send LL-only as 16-bytes
NH instead of a GUA (global unicast).
Fixes: db853cc97e ("bgpd: Implement Link-Local Next Hop capability")
Signed-off-by: Donatas Abraitis <donatas@opensourcerouting.org>
Currently the AIGP is always incremented when a route with the
attribute is advertised. That is incorrect when the nexthop is
unchanged, as is commonly the case in route reflection.
Adjust the AIGP for propagation only when the nexthop is set
to ourselves.
Signed-off-by: Enke Chen <enchen@paloaltonetworks.com>
Fix static-analyser warnings with BGP labels:
> $ scan-build make -j12
> bgpd/bgp_updgrp_packet.c:819:10: warning: Access to field 'extra' results in a dereference of a null pointer (loaded from variable 'path') [core.NullDereference]
> ? &path->extra->labels->label[0]
> ^~~~~~~~~
Signed-off-by: Louis Scalbert <louis.scalbert@6wind.com>
Replace IPv4-mapped IPv6 at update forwarding because the peer may not
be able to create a route with the IPv4-mapped IPv6.
Signed-off-by: Louis Scalbert <louis.scalbert@6wind.com>
The code was expected that no IPv6 global address was present but the
previous commit was replacing nexthop.v6global by the link-local address
instead of un-setting it in case of removal of the IPv6 global.
Set also ipv4-mapped ipv6 address as nexthop when a link-local is found
and it is an ipv4 prefix over ipv6 nexthop.
Signed-off-by: Louis Scalbert <louis.scalbert@6wind.com>
This reverts commit 0325116a27.
It was causing an issue where a nexthop for IPv6 over an IPv4 session
was always rewritten to an IPv4-mapped IPv6 address even when a valid
IPv6 global address was existing.
Link: https://github.com/FRRouting/frr/issues/15610
Signed-off-by: Louis Scalbert <louis.scalbert@6wind.com>
6vPE enables the announcement of IPv6 VPN prefixes through an IPv4 BGP
session. In this scenario, the next hop addresses for these prefixes are
represented in an IPv4-mapped IPv6 format, noted as ::ffff:[IPv4]. This
format indicates to the peer that it should route these IPv6 addresses
using information from the IPv4 nexthop. For example:
> Path Attribute - MP_REACH_NLRI
> [...]
> Address family identifier (AFI): IPv6 (2)
> Subsequent address family identifier (SAFI): Labeled VPN Unicast (128)
> Next hop: RD=0:0 IPv6=::ffff:192.0.2.5 RD=0:0 Link-local=fe80::501d:42ff:feef:b021
> Number of Subnetwork points of attachment (SNPA): 0
This rule is set out in RFC4798:
> The IPv4 address of the egress 6PE router MUST be encoded as an
> IPv4-mapped IPv6 address in the BGP Next Hop field.
However, in some situations, bgpd sends a standard nexthop IPv6 address
instead of an IPv4-mapped IPv6 address because the outgoing interface for
the BGP session has a valid IPv6 address. This is problematic because
the peer router may not be able to route the nexthop IPv6 address (ie.
if the outgoing interface has not IPv6).
Fix the issue by always sending a IPv4-mapped IPv6 address as nexthop
when the BGP session is on IPv4 and address family IPv6.
Link: https://datatracker.ietf.org/doc/html/rfc4798#section-2
Fixes: 92d6f76 ("lib,zebra,bgpd: Fix for nexthop as IPv4 mapped IPv6 address")
Signed-off-by: Louis Scalbert <louis.scalbert@6wind.com>
RFC 3032 defines:
A value of 2 represents the "IPv6 Explicit NULL Label".
This label value is only legal at the bottom of the label
stack. It indicates that the label stack must be popped,
and the forwarding of the packet must then be based on the
IPv6 header.
Before this patch we set 128, but it was even more wrong, because it was sent
in host-byte order, not the network-byte.
Signed-off-by: Donatas Abraitis <donatas@opensourcerouting.org>
The advertised label value from mpls vpn routes is not modified
when the advertised next-hop is modified to next-hop-self.
Actually, the original label value received is redistributed as
is, whereas the new_label value bound in the nexthop label
bind entry should be used.
Only the VPN entries that contain MPLS information, and that
are redistributed between distinct peers, will have a label
value to advertise.
- no SRv6 attribute
- no local prefix
- no exported VPN prefixes from a VRF
If the advertisement to a given peer has the next-hop modified,
then the new label value will be picked up. The considered cases
are peers configured with 'next-hop-self' option, or ebgp peerings
without the 'next-hop-unchanged' option.
Note that the the NLRI format will follow the rfc3107 format, as
multiple label values for MPLS VPN NLRIs are not supported (the
rfc8277 is not supported).
Note also that the case where an outgoing route-map is applied to
the outgoing neighbor is not considered in this commit.
Signed-off-by: Philippe Guibert <philippe.guibert@6wind.com>
This is a first in a series of commits, whose goal is to rename
the thread system in FRR to an event system. There is a continual
problem where people are confusing `struct thread` with a true
pthread. In reality, our entire thread.c is an event system.
In this commit rename the thread.[ch] files to event.[ch].
Signed-off-by: Donald Sharp <sharpd@nvidia.com>
Given that the following topology, route server MUST not modify NEXT_HOP
attribute because route server isn't in the actual routing path. This
behavior is required to comply RFC7947
(Router A) <-(eBGP peer)-> (Route Server) <-(eBGP peer)-> (Router B)
RFC7947 says as follows:
> As the route server does not participate in the actual routing of
> traffic, the NEXT_HOP attribute MUST be passed unmodified to the route
> server clients, similar to the "third-party" next-hop
> feature described in Section 5.1.3. of [RFC4271].
However, current FRR is violating RFC7947 in some cases. If routers and
route server established BGP peer over IPv6 connection and routers
advertise ipv4-vpn routes through route server, route server will modify
NEXT_HOP attribute in these advertisements.
This is because the condition to check whether NEXT_HOP attribute should
be changed or not is wrong. We should use (afi, safi) as the key to
check, but (nhafi, safi) is actually used. This causes the RFC7947
violation.
Signed-off-by: Ryoga Saito <ryoga.saito@linecorp.com>
Description:
Change is intended for fixing the inconsistencies present
while adjusting the SNT counters with default originate.
- SNT counter gets incremented on every change of policy associated
with default-originate, leading to inconsistencies.
- This fix has been added to ensure that the SNT counters gets
incremented and decremented only once during the creation and
deletion workflow of default-originate, and prevents
incrementing the counter during update flow.
Co-authored-by: Abhinay Ramesh <rabhinay@vmware.com>
Signed-off-by: Iqra Siddiqui <imujeebsiddi@vmware.com>
Abstract:
- The command "neighbor PEER maximum-prefix-out NUMBER" cannot be applied
without clearing the BGP neighbor.
- Apply the maximum-prefix-out value as soon as it is modified without
clearing the neighbor.
subgroup_update_packet() and subgroup_withdraw_packet() respectively
manages the announcement and withdrawal BGP message to the peer.
subgrp->scount counter counts the number of sent prefixes.
Before the patch, the maximum out prefix limitation was applied in
subgroup_update_packet() in order that subgrp->scount never exceeds the
limit. Setting a limit inferior to the effective number of sent prefix
did not result in sending any withdrawal message to reduce the number of
sent prefixes. Without clearing the BGP neighbor, the limitation only
applied to the announcement of new prefixes when the limitation was
over.
With the patch, the limitation is checked in subgroup_announce_check().
The function is intended to say whether a prefix has to be announced in
regards to the prefix-list, route-map... Now when a maximum-prefix-out
value is changed/removed, the neighbor AFI/SAFI table is re-parsed in
the same way as for the application of route-map, prefix-lists...
Signed-off-by: Louis Scalbert <louis.scalbert@6wind.com>
Gateway IP overlay index is generated for EVPN RT-5 when following CLI is
configured.
router bgp 100 vrf vrf-blue
address-family l2vpn evpn
advertise ipv4 unicast gateway-ip
advertise ipv6 unicast gateway-ip
BGP nexthop of the VRF IP/IPv6 route is set as the gateway IP of the
corresponding EVPN RT-5
Signed-off-by: Ameya Dharkar <adharkar@vmware.com>
When FRR creates a adj_out data structure we lock the `struct
bgp_dest` node associated with it. On freeing of this data
structure and removing the lock it was not associated with
the actual free of the adjacency structure. Let's clean up
the lock/unlock to be centralized to the alloc/free of the adj_out.
Signed-off-by: Donald Sharp <sharpd@nvidia.com>
Added a macro to validate the v4 mapped v6 address.
Modified bgp receive & send updates for v4 mapped v6 address as
nexthop and installing it as recursive nexthop in RIB.
Minor change in fpm while sending the routes for nexthop as
v4 mapped v6 address.
Signed-off-by: Kaushik <kaushik@niralnetworks.com>
This is the bulk part extracted from "bgpd: Convert from `struct
bgp_node` to `struct bgp_dest`". It should not result in any functional
change.
Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>
Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
Add new function `bgp_node_get_prefix()` and modify
the bgp code base to use it.
This is prep work for the struct bgp_dest rework.
Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>
Some were converted to bool, where true/false status is needed.
Converted to void only those, where the return status was only false or true.
Signed-off-by: Donatas Abraitis <donatas.abraitis@gmail.com>
