Move mp_nexthop_prefer_global boolean attribute to nh_flags. It does
not currently save memory because of the packing.
Signed-off-by: Louis Scalbert <louis.scalbert@6wind.com>
In the case of SRv6-VPN we track the reachability
to the SID. We check that the SID is available
in the BGP update and then we check the nexthop
reachability.
Fixes 7f8c7d9 ("bgpd: ignore nexthop validation for srv6-vpn")
Signed-off-by: Dmytro Shytyi <dmytro.shytyi@6wind.com>
Signed-off-by: Philippe Guibert <philippe.guibert@6wind.com>
Enable the SRv6 SID prefix generation in make_prefix()
function of bgp_nht.c.
Signed-off-by: Dmytro Shytyi <dmytro.shytyi@6wind.com>
fixup: bgpd: extend make_prefix to form srv6-based prefix
The following configuration creates an infinite routing leaking loop
because 'rt vpn both' parameters are the same in both VRFs.
> router bgp 5227 vrf r1-cust4
> no bgp network import-check
> bgp router-id 192.168.1.1
> address-family ipv4 unicast
> network 28.0.0.0/24
> rd vpn export 10:12
> rt vpn both 52:100
> import vpn
> export vpn
> exit-address-family
> !
> router bgp 5227 vrf r1-cust5
> no bgp network import-check
> bgp router id 192.168.1.1
> address-family ipv4 unicast
> network 29.0.0.0/24
> rd vpn export 10:13
> rt vpn both 52:100
> import vpn
> export vpn
> exit-address-family
The previous commit has added a routing leak update when a nexthop
update is received from zebra. It indirectly calls
bgp_find_or_add_nexthop() in which a static route triggers a nexthop
cache entry registration that triggers a nexthop update from zebra.
Do not register again the nexthop cache entry if the BGP_STATIC_ROUTE is
already set.
Signed-off-by: Louis Scalbert <louis.scalbert@6wind.com>
If 'bgp network import-check' is defined on the source BGP session,
prefixes that are defined with the network command cannot be leaked to
the other VRFs BGP table even if they are present in the origin VRF RIB
if the 'rt import' statement is defined after the 'network <prefix>'
ones.
When a prefix nexthop is updated, update the prefix route leaking. The
current state of nexthop validation is now stored in the attributes of
the bgp path info. Attributes are compared with the previous ones at
route leaking update so that a nexthop validation change now triggers
the update of destination VRF BGP table.
Signed-off-by: Louis Scalbert <louis.scalbert@6wind.com>
"if not XX else" statements are confusing.
Replace two "if not XX else" statements by "if XX else" to prepare next
commits. The patch is only cosmetic.
Signed-off-by: Louis Scalbert <louis.scalbert@6wind.com>
This rework separates l3nhg functionality from the nexthop
tracking code, by introducing two bgp_nhg.[ch] files. The
calling functions are renamed from bgp_l3nhg* to bgp_nhg*.
Signed-off-by: Philippe Guibert <philippe.guibert@6wind.com>
In some cases BGP can be monitoring the same prefix
in both the nexthop and import check tables. If this
is the case, when unregistering one bnc from one table
make sure we are not still registered in the other
Example of the problem:
r1(config-router)# address-family ipv4 uni
r1(config-router-af)# no network 192.168.100.41/32
r1(config-router-af)# exit
r1# show bgp import-check-table
Current BGP import check cache:
r1# show bgp nexthop
Current BGP nexthop cache:
192.168.100.41 valid [IGP metric 0], #paths 1, peer 192.168.100.41
if r1-eth0
Last update: Wed Dec 6 11:01:40 2023
BGP now believes it is only watching 192.168.100.41 in the nexthop
cache, but zebra doesn't have anything:
r1# show ip import-check
VRF default:
Resolve via default: on
r1# show ip nht
VRF default:
Resolve via default: on
So if anything happens to the route that is being matched for
192.168.100.41 bgp is no longer going to be notified about this.
The source of this problem is that zebra has dropped the two different
tables into 1 table, while bgp has 2 tables to track this. The solution
to this problem (other than the rewrite that is being done ) is to have
BGP have a bit of smarts about looking in both tables for the bnc and
if found in both don't send the delete of the prefix tracking to zebra.
Signed-off-by: Donald Sharp <sharpd@nvidia.com>
In zebra, the import check table and the nexthop check tables
were combined. This leaves an issue where when bgp happens
to have a tracked address in both the import check table
and the nexthop track table that are the same address.
When the the item is removed from one table the call
to remove it from zebra removes tracking for the other
table.
Combine the two tables together and keep track where
they came from for processing in bgpd.
Signed-off-by: Donald Sharp <sharpd@nvidia.com>
For v4 nexthops, ifindex was being set. Modified the check to set
ifindex only for v6 nexthops. Also modified the check to set ifindex
only if the v6 nexthop matches peer's LL address.
Signed-off-by: Pooja Jagadeesh Doijode <pdoijode@nvidia.com>
Problem:
On GR helper, paths learnt from an interface based peer were linked
to bnc with ifindex=0. During restart of GR peer, BGP (unnumbered)
session (with GR restarter peer) goes down on GR helper but the routes
are retained. Later, when BGP receives an interface up event, it
will process all the paths associated with BNC whose ifindex matches the
ifindex of the interface for which UP event is received. However, paths
associated with bnc that has ifindex=0 were not being reinstalled since
ifindex=0 doesn't match ifindex of any interfaces. This results in
BGP routes not being reinstalled in zebra and kernel.
Fix:
For paths learnt from an interface based peer, set the
ifindex to peer's interface ifindex so that correct
peer based nexthop can be found and linked to the path.
Signed-off-by: Donald Sharp sharpd@nvidia.com
Signed-off-by: Pooja Jagadeesh Doijode <pdoijode@nvidia.com>
Even if some of the attributes in bgp_path_info_extra are
not used, their memory is still allocated every time. It
cause a waste of memory.
This commit code deletes all unnecessary attributes and
changes the optional attributes to pointer storage. Memory
will only be allocated when they are actually used. After
optimization, extra info related memory is reduced by about
half(~400B -> ~200B).
Signed-off-by: Valerian_He <1826906282@qq.com>
Assuming field 'ifindex_ipv6_ll' is not equal to field 'ifindex', then
nhop_found is just a garbage, let's avoid that.
Signed-off-by: Donatas Abraitis <donatas@opensourcerouting.org>
In BGP, when an interface event is detected or triggered,
the BNC that have a next-hop that matches the interface
are not evaluated.
The paths attached to the bnc context are evaluated in the
following situation:
- In the up event case, if at least one next-hop interface
matched the event interface.
- In the down event case, if there is no alternate next-hop
that does not use the event interface.
Signed-off-by: Philippe Guibert <philippe.guibert@6wind.com>
This commit changes the 'ifindex' name of the bnc structure.
As it is used only to handle ipv6 link local addresses, let
us use the 'ifindex_ipv6_ll' naming to avoid any confusions
with the ifindex value of the resolved next-hops of the bnc
structure.
Signed-off-by: Philippe Guibert <philippe.guibert@6wind.com>
`bnc->ifindex` should not be with 0 ( IFINDEX_INTERNAL ), so we can ignore
the wrong interface to make it safe.
Signed-off-by: anlan_cs <vic.lan@pica8.com>
When exporting redistributed prefixes from a given VRF
to an MPLS VPN network, the paths are always considered
as valid whereas it should not always be the case.
At exportation, a new MPLS VPN path is built in. Then
nexthop tracking is applied to the new path, and the
SAFI_MPLS_VPN parameter is used to tell the NHT code
to just check for the next-hop reachability. The previous
commit was wrongly considering that nexthop tracking was
never applied to mpls vpn networks. Ensure that nexthop
tracking for exported paths behaves as usual.
Fix this by not returning always 1 in the 'bgp_find_or_add_nexthop()'
function if the passed 'pi' parameter is a 'BGP_IMPORTED_ROUTE'
sub-type entry.
Fixes: 74be3f3ea9ec ("bgpd: track mpls vpn nexthops")
Signed-off-by: Philippe Guibert <philippe.guibert@6wind.com>
Current implementation does not offer a new label to bind
to a received VPN route entry to redistribute with that new
label.
This commit allocates a label for VPN entries that have
a valid label, and a reachable next-hop interface that is
configured as follows:
> interface eth0
> mpls bgp l3vpn-multi-domain-switching
> exit
An mplsvpn next-hop label binding entry is created in an mpls
vpn nexthop label bind hash table of the current BGP instance.
That mpls vpn next-hop label entry is indexed by the (next-hop,
orig_label) values provided by the incoming updates, and shared
with other updates having the same (next-hop, orig_label) values.
A new 'LP_TYPE_BGP_L3VPN_BIND' label value is picked up from the
zebra mpls label pool, and assigned to the new_label attribute.
The 'bgp_path_info' appends a 'bgp_mplsvpn_nh_label_bind' structure
to the 'mplsvpn' union structure. Both structures in the union are not
used at the same, as the paths are either VRF updates to export, or MPLS
VPN updates. Using an union gives a 24 bytes memory gain compared to if
the structures had not been in an union (24 bytes compared to 48 bytes).
Signed-off-by: Philippe Guibert <philippe.guibert@6wind.com>
There is no nexthop reachability information for
received MPLS VPN prefixes.
This information is necessary when BGP also acts
as LSR device, and is needed to create an MPLS entry
between two BGP speakers: the next-hop to pick-up
in the MPLS entry has to be connected.
The nexthop reachability information is available
for other non MPLS VPN prefixes, and is handled
by the bgp nexthop cache (bnc) contexts.
Extend the usage of the BNC contexts for L3VPN
prefixes.
Note that the MPLS VPN routes had to be redistributed
as before, to avoid breaking existing deployments
that use FRR as route reflectors. Because of this, the
nexthop reachability status has been maintained to OK
for MPLS VPN prefixes.
Note also that the label allocation per nexthop tracking
was wrongly using the MPLS VPN safi to get a valid BNC
context, when choosing which label to return in the
'vpn_leak_from_vrf_get_per_nexthop_label()' function.
Fix this by using SAFI_UNICAST instead.
Fixes: 577be36a41 ("bgpd: add support for l3vpn per-nexthop label")
Link: https://github.com/FRRouting/frr/pull/13380
Signed-off-by: Philippe Guibert <philippe.guibert@6wind.com>
In BGP, when an interface event is detected or triggered,
the BNC that have a next-hop that matches the interface
are not evaluated.
The paths attached to the bnc context are evaluated in the
following situation:
- In the up event case, if at least one next-hop interface
matched the event interface.
- In the down event case, if there is no alternate next-hop
that does not use the event interface.
Signed-off-by: Philippe Guibert <philippe.guibert@6wind.com>
This commit changes the 'ifindex' name of the bnc structure.
As it is used only to handle ipv6 link local addresses, let
us use the 'ifindex_ipv6_ll' naming to avoid any confusions
with the ifindex value of the resolved next-hops of the bnc
structure.
Signed-off-by: Philippe Guibert <philippe.guibert@6wind.com>
The label allocation per nexthop mode requires to use a nexthop
tracking context. For redistributed routes, a nexthop tracking
context is created, and the resolution helps to know the real
nexthop ip address used. The below configuration example has
been used:
> vrf vrf1
> ip route 172.31.0.14/32 192.0.2.14
> ip route 172.31.0.15/32 192.0.2.12
> ip route 172.31.0.30/32 192.0.2.30
> exit
> router bgp 65500 vrf vrf1
> address-family ipv4 unicast
> redistribute static
> label vpn export per-nexthop
> [..]
The static routes are correctly imported in the BGP IPv4 RIB.
Contrary to label allocation per vrf mode, some nexthop tracking
are created/or reused:
> # show bgp vrf vrf1 nexthop
> 192.0.2.12 valid [IGP metric 0], #paths 3, peer 192.0.2.12
> if r1-eth1
> Last update: Fri Jan 13 15:49:42 2023
> 192.0.2.14 valid [IGP metric 0], #paths 1
> if r1-eth1
> Last update: Fri Jan 13 15:49:42 2023
> 192.0.2.30 valid [IGP metric 0], #paths 1
> if r1-eth1
> Last update: Fri Jan 13 15:49:51 2023
> [..]
This results in having a BGP VPN route for each of the static
routes:
> # show bgp ipv4 vpn
> [..]
> Route Distinguisher: 444:1
> *> 172.31.0.14/32 192.0.2.14@9< 0 32768 ?
> *> 172.31.0.15/32 192.0.2.12@9< 0 32768 ?
> *> 172.31.0.30/32 192.0.2.30@9< 0 32768 ?
> [..]
Without that patch, only the redistributed routes that rely on a
pre-existing nexthop tracking context could be exported.
Also, a command in the code about redistributed routes is modified
accordingly, to explain that redistribute routes may be submitted
to nexthop tracking in the case label allocation per next-hop is
used.
note:
VNC routes have been removed from the redistribution,
because of a test failure in the bgp_l3vpn_to_bgp_direct test.
Signed-off-by: Philippe Guibert <philippe.guibert@6wind.com>
This commit introduces a new method to associate a label to
prefixes to export to a VPNv4 backbone. All the methods to
associate a label to a BGP update is documented in rfc4364,
chapter 4.3.2. Initially, the "single label for an entire
VRF" method was available. This commit adds "single label
for each attachment circuit" method.
The change impacts the control-plane, because each BGP update
is checked to know if the nexthop has reachability in the VRF
or not. If this is the case, then a unique label for a given
destination IP in the VRF will be picked up. This label will
be reused for an other BGP update that will have the same
nexthop IP address.
The change impacts the data-plane, because the MPLs pop
mechanism applied to incoming labelled packets changes: the
MPLS label is popped, and the packet is directly sent to the
connected nexthop described in the previous outgoing BGP VPN
update.
By default per-vrf mode is done, but the user may choose
the per-nexthop mode, by using the vty command from the
previous commit. In the latter case, a per-vrf label
will however be allocated to handle networks that are not directly
connected. This is the case for local traffic for instance.
The change also include the following:
- ECMP case
In case a route is learnt in a given VRF, and is resolved via an
ECMP nexthop. This implies that when exporting the route as a BGP
update, if label allocation per nexthop is used, then two possible
MPLS values could be picked up, which is not possible with the
current implementation. Actually, the NLRI for VPNv4 stores one
prefix, and one single label value, not two. Today, RFC8277 with
multiple label capability is not yet available.
To avoid this corner case, when a route is resolved via more than one
nexthop, the label allocation per nexthop will not apply, and the
default per-vrf label will be chosen.
Let us imagine BGP redistributes a static route using the `172.31.0.20`
nexthop. The nexthop resolution will find two different nexthops fo a
unique BGP update.
> r1# show running-config
> [..]
> vrf vrf1
> ip route 172.31.0.30/32 172.31.0.20
> r1# show bgp vrf vrf1 nexthop
> [..]
> 172.31.0.20 valid [IGP metric 0], #paths 1
> gate 192.0.2.11
> gate 192.0.2.12
> Last update: Mon Jan 16 09:27:09 2023
> Paths:
> 1/1 172.31.0.30/32 VRF vrf1 flags 0x20018
To avoid this situation, BGP updates that resolve over multiple
nexthops are using the unique per-vrf label.
- recursive route case
Prefixes that need a recursive route to be resolved can
also be eligible for mpls allocation per nexthop. In that
case, the nexthop will be the recursive nexthop calculated.
To achieve this, all nexthop types in bnc contexts are valid,
except for the blackhole nexthops.
- network declared prefixes
Nexthop tracking is used to look for the reachability of the
prefixes. When the the 'no bgp network import-check' command
is used, network declared prefixes are maintained active,
even if there is no active nexthop.
Signed-off-by: Philippe Guibert <philippe.guibert@6wind.com>
Effectively a massive search and replace of
`struct thread` to `struct event`. Using the
term `thread` gives people the thought that
this event system is a pthread when it is not
Signed-off-by: Donald Sharp <sharpd@nvidia.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>
The label allocation per nexthop mode requires to use a nexthop
tracking context. For redistributed routes, a nexthop tracking
context is created, and the resolution helps to know the real
nexthop ip address used. The below configuration example has
been used:
> vrf vrf1
> ip route 172.31.0.14/32 192.0.2.14
> ip route 172.31.0.15/32 192.0.2.12
> ip route 172.31.0.30/32 192.0.2.30
> exit
> router bgp 65500 vrf vrf1
> address-family ipv4 unicast
> redistribute static
> label vpn export per-nexthop
> [..]
The static routes are correctly imported in the BGP IPv4 RIB.
Contrary to label allocation per vrf mode, some nexthop tracking
are created/or reused:
> # show bgp vrf vrf1 nexthop
> 192.0.2.12 valid [IGP metric 0], #paths 3, peer 192.0.2.12
> if r1-eth1
> Last update: Fri Jan 13 15:49:42 2023
> 192.0.2.14 valid [IGP metric 0], #paths 1
> if r1-eth1
> Last update: Fri Jan 13 15:49:42 2023
> 192.0.2.30 valid [IGP metric 0], #paths 1
> if r1-eth1
> Last update: Fri Jan 13 15:49:51 2023
> [..]
This results in having a BGP VPN route for each of the static
routes:
> # show bgp ipv4 vpn
> [..]
> Route Distinguisher: 444:1
> *> 172.31.0.14/32 192.0.2.14@9< 0 32768 ?
> *> 172.31.0.15/32 192.0.2.12@9< 0 32768 ?
> *> 172.31.0.30/32 192.0.2.30@9< 0 32768 ?
> [..]
Without that patch, only the redistributed routes that rely on a
pre-existing nexthop tracking context could be exported.
Also, a command in the code about redistributed routes is modified
accordingly, to explain that redistribute routes may be submitted
to nexthop tracking in the case label allocation per next-hop is
used.
note:
VNC routes have been removed from the redistribution,
because of a test failure in the bgp_l3vpn_to_bgp_direct test.
Signed-off-by: Philippe Guibert <philippe.guibert@6wind.com>
This commit introduces a new method to associate a label to
prefixes to export to a VPNv4 backbone. All the methods to
associate a label to a BGP update is documented in rfc4364,
chapter 4.3.2. Initially, the "single label for an entire
VRF" method was available. This commit adds "single label
for each attachment circuit" method.
The change impacts the control-plane, because each BGP update
is checked to know if the nexthop has reachability in the VRF
or not. If this is the case, then a unique label for a given
destination IP in the VRF will be picked up. This label will
be reused for an other BGP update that will have the same
nexthop IP address.
The change impacts the data-plane, because the MPLs pop
mechanism applied to incoming labelled packets changes: the
MPLS label is popped, and the packet is directly sent to the
connected nexthop described in the previous outgoing BGP VPN
update.
By default per-vrf mode is done, but the user may choose
the per-nexthop mode, by using the vty command from the
previous commit. In the latter case, a per-vrf label
will however be allocated to handle networks that are not directly
connected. This is the case for local traffic for instance.
The change also include the following:
- ECMP case
In case a route is learnt in a given VRF, and is resolved via an
ECMP nexthop. This implies that when exporting the route as a BGP
update, if label allocation per nexthop is used, then two possible
MPLS values could be picked up, which is not possible with the
current implementation. Actually, the NLRI for VPNv4 stores one
prefix, and one single label value, not two. Today, RFC8277 with
multiple label capability is not yet available.
To avoid this corner case, when a route is resolved via more than one
nexthop, the label allocation per nexthop will not apply, and the
default per-vrf label will be chosen.
Let us imagine BGP redistributes a static route using the `172.31.0.20`
nexthop. The nexthop resolution will find two different nexthops fo a
unique BGP update.
> r1# show running-config
> [..]
> vrf vrf1
> ip route 172.31.0.30/32 172.31.0.20
> r1# show bgp vrf vrf1 nexthop
> [..]
> 172.31.0.20 valid [IGP metric 0], #paths 1
> gate 192.0.2.11
> gate 192.0.2.12
> Last update: Mon Jan 16 09:27:09 2023
> Paths:
> 1/1 172.31.0.30/32 VRF vrf1 flags 0x20018
To avoid this situation, BGP updates that resolve over multiple
nexthops are using the unique per-vrf label.
- recursive route case
Prefixes that need a recursive route to be resolved can
also be eligible for mpls allocation per nexthop. In that
case, the nexthop will be the recursive nexthop calculated.
To achieve this, all nexthop types in bnc contexts are valid,
except for the blackhole nexthops.
- network declared prefixes
Nexthop tracking is used to look for the reachability of the
prefixes. When the the 'no bgp network import-check' command
is used, network declared prefixes are maintained active,
even if there is no active nexthop.
Signed-off-by: Philippe Guibert <philippe.guibert@6wind.com>
This causes early return. peer->conf is NULL for IPv6 link-local peering,
and the session never establish.
Signed-off-by: Donatas Abraitis <donatas@opensourcerouting.org>
RD may be built based on an AS number. Like for the AS, the RD
may use the AS notation. The two below examples can illustrate:
RD 1.1:20 stands for an AS4B:NN RD with AS4B=65536 in dot format.
RD 0.1:20 stands for an AS2B:NNNN RD with AS2B=0.1 in dot+ format.
This commit adds the asnotation mode to prefix_rd2str() API so as
to pick up the relevant display.
Two new printfrr extensions are available to display the RD with
the two above display methods.
- The pRDD extension stands for dot asnotation format
- The pRDE extension stands for dot+ asnotation format.
- The pRD extension has been renamed to pRDP extension
The code is changed each time '%pRD' printf extension is called.
Possibly, the asnotation may change the output, then a macro defines
the asnotation mode to use. A side effect of forging the mode to
use is that the string could not be concatenated with other strings
in vty_out and snprintfrr. Those functions have been called multiple
times. When zlog_debug needs to display the RD with some other string,
the prefix_rd2str() old API is used instead of the printf extension.
Some code has been kept untouched:
- code related to running-config. Actually, wherever an RD is displayed,
its configured name should be dumped.
- bgp rfapi code
- bgp evpn multihoming code (partially done), since the logic is
missing to get the asnotation of 'struct bgp_evpn_es'.
Signed-off-by: Philippe Guibert <philippe.guibert@6wind.com>
Previous commits have introduced a new 8 bits nh_flag in the attr
struct that has increased the memory footprint.
Move the mp_nexthop_prefer_global boolean in the attr structure that
takes 8 bits to the new nh_flag in order to go back to the previous
memory utilization.
Signed-off-by: Louis Scalbert <louis.scalbert@6wind.com>
The following configuration creates an infinite routing leaking loop
because 'rt vpn both' parameters are the same in both VRFs.
> router bgp 5227 vrf r1-cust4
> no bgp network import-check
> bgp router-id 192.168.1.1
> address-family ipv4 unicast
> network 28.0.0.0/24
> rd vpn export 10:12
> rt vpn both 52:100
> import vpn
> export vpn
> exit-address-family
> !
> router bgp 5227 vrf r1-cust5
> no bgp network import-check
> bgp router id 192.168.1.1
> address-family ipv4 unicast
> network 29.0.0.0/24
> rd vpn export 10:13
> rt vpn both 52:100
> import vpn
> export vpn
> exit-address-family
The previous commit has added a routing leak update when a nexthop
update is received from zebra. It indirectly calls
bgp_find_or_add_nexthop() in which a static route triggers a nexthop
cache entry registration that triggers a nexthop update from zebra.
Do not register again the nexthop cache entry if the BGP_STATIC_ROUTE is
already set.
Signed-off-by: Louis Scalbert <louis.scalbert@6wind.com>
