The bgp labelpool code is grabbing the vpn policy data structure.
This vpn_policy has a pointer to the bgp data structure. If
a item placed on the bgp label pool workqueue happens to sit
there for the microsecond or so and the operator issues a
`no router bgp...` command that corresponds to the vpn_policy
bgp pointer, when the workqueue is run it will crash because
the bgp pointer is now freed and something else owns it.
Modify the labelpool code to store the vrf id associated
with the request on the workqueue. When you wake up
if the vrf id still has a bgp pointer allow the request
to continue, else drop it.
Signed-off-by: Donald Sharp <sharpd@nvidia.com>
Both the label manager and table manager zapi code send data requests via zapi
to zebra and then immediately listen for a response from zebra. The problem here
is of course that the listen part is throwing away any zapi command that is not
the one it is looking for.
ISIS/OSPF and PIM all have synchronous abilities via zapi, which they all
do through a special zapi connection to zebra. BGP needs to follow this model
as well. Additionally the new zclient_sync connection that should be created,
a once a second timer should wake up and read any data on the socket to
prevent problems too much data accumulating in the socket.
```
r3# sh bgp labelpool summary
Labelpool Summary
-----------------
Ledger: 3
InUse: 3
Requests: 0
LabelChunks: 1
Pending: 128
Reconnects: 1
r3# sh bgp labelpool inuse
Prefix Label
---------------------------
10.0.0.1/32 16
192.168.31.0/24 17
192.168.32.0/24 18
r3#
```
Signed-off-by: Donatas Abraitis <donatas@opensourcerouting.org>
Redistributing mpls vpn prefixes with a new label
requires picking up unused MPLS local labels.
Today, there is an MPLS label pool which is owned
by the zebra daemon. BGP gets a chunk of labels
that are shared with the multiple usage of the BGP
daemon. A label type attribute is used whenever
BGP needs a new label value.
The 'LP_TYPE_BGP_L3VPN_BIND' label type will be used
to allocate the MPLS labels that will be bound to
the original next-hop, and label value of an L3VPN
update.
Signed-off-by: Louis Scalbert <louis.scalbert@6wind.com>
Signed-off-by: Philippe Guibert <philippe.guibert@6wind.com>
The following command is made available to list the labels
allocated per-nexthop, along with the paths registered to it.
> # show bgp vrf vrf1 label-nexthop
> Current BGP label nexthop cache for IP, VRF vrf1
> 192.0.2.11, label 20 #paths 3
> if r1-eth1
> Last update: Mon Jan 16 18:52:11 2023
> 192.0.2.12, label 17 #paths 2
> if r1-eth1
> Last update: Mon Jan 16 18:52:08 2023
> 192.0.2.14, label 18 #paths 1
> if r1-eth1
> Last update: Mon Jan 16 18:52:07 2023
> 192.168.255.13, label 19 #paths 1
> if r1-eth2
> Last update: Mon Jan 16 18:52:10 2023
Signed-off-by: Philippe Guibert <philippe.guibert@6wind.com>
A timer attribute is added for each label nexthop entry, in order
to know when the last change occured.
The timer value will be used for troubleshooting by a show
command in the next commit.
Signed-off-by: Philippe Guibert <philippe.guibert@6wind.com>
BGP MPLSVPN next hop label allocation was using only the next-hop
IP address. As MPLSVPN contexts rely on bnc contexts, the real
nexthop interface is known, and the LSP entry to enter can apply
to the specific interface. To illustrate, the BGP service is able
to handle the following two iproute2 commands:
> ip -f mpls route add 105 via inet 192.0.2.45 dev r1-eth1
> ip -f mpls route add 105 via inet 192.0.2.46 dev r1-eth2
Signed-off-by: Philippe Guibert <philippe.guibert@6wind.com>
This commit introduces the necessary structs and apis to
create the cache entries that store the label information
associated to a given nexthop.
A hash table is created in each BGP instance for all the
AFIs: IPv4 and IPv6. That hash table is initialised.
An API to look and/or create an entry based on a given
nexthop.
Signed-off-by: Philippe Guibert <philippe.guibert@6wind.com>
A new label type is introduced: LP_TYPE_NEXTHOP. This new
label type will be used in next commits to allocate labels
for a specific nexthop IP address.
The commit changes add vty and json outputs to display
the new label type and the label values associated.
Signed-off-by: Philippe Guibert <philippe.guibert@6wind.com>
The following command is made available to list the labels
allocated per-nexthop, along with the paths registered to it.
> # show bgp vrf vrf1 label-nexthop
> Current BGP label nexthop cache for IP, VRF vrf1
> 192.0.2.11, label 20 #paths 3
> if r1-eth1
> Last update: Mon Jan 16 18:52:11 2023
> 192.0.2.12, label 17 #paths 2
> if r1-eth1
> Last update: Mon Jan 16 18:52:08 2023
> 192.0.2.14, label 18 #paths 1
> if r1-eth1
> Last update: Mon Jan 16 18:52:07 2023
> 192.168.255.13, label 19 #paths 1
> if r1-eth2
> Last update: Mon Jan 16 18:52:10 2023
Signed-off-by: Philippe Guibert <philippe.guibert@6wind.com>
A timer attribute is added for each label nexthop entry, in order
to know when the last change occured.
The timer value will be used for troubleshooting by a show
command in the next commit.
Signed-off-by: Philippe Guibert <philippe.guibert@6wind.com>
BGP MPLSVPN next hop label allocation was using only the next-hop
IP address. As MPLSVPN contexts rely on bnc contexts, the real
nexthop interface is known, and the LSP entry to enter can apply
to the specific interface. To illustrate, the BGP service is able
to handle the following two iproute2 commands:
> ip -f mpls route add 105 via inet 192.0.2.45 dev r1-eth1
> ip -f mpls route add 105 via inet 192.0.2.46 dev r1-eth2
Signed-off-by: Philippe Guibert <philippe.guibert@6wind.com>
This commit introduces the necessary structs and apis to
create the cache entries that store the label information
associated to a given nexthop.
A hash table is created in each BGP instance for all the
AFIs: IPv4 and IPv6. That hash table is initialised.
An API to look and/or create an entry based on a given
nexthop.
Signed-off-by: Philippe Guibert <philippe.guibert@6wind.com>
A new label type is introduced: LP_TYPE_NEXTHOP. This new
label type will be used in next commits to allocate labels
for a specific nexthop IP address.
The commit changes add vty and json outputs to display
the new label type and the label values associated.
Signed-off-by: Philippe Guibert <philippe.guibert@6wind.com>
- double the size of each new chunk request from zebra
- use bitfields to track label allocations in a chunk
- When allocating:
- skip chunks with no free labels
- search biggest chunks first
- start search in chunk where last search ended
- Improve API documentation in comments (bgp_lp_get() and callback)
- Tweak formatting of "show bgp labelpool chunks"
- Add test features (compiled conditionally on BGP_LABELPOOL_ENABLE_TESTS)
Signed-off-by: G. Paul Ziemba <paulz@labn.net>
Again, the FIFO_* stuff in lib/fifo.h is no different from a simple
unsorted list. Just use DECLARE_LIST here so we can get rid of FIFO_*.
Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
This commit is the last missing piece to complete BGP LU support in bgpd. To this moment, bgpd (and zebra) supported auto label assignment only for prefixes leaked from VRFs to vpn and for MPLS SR prefixes. This adds auto label assignment to other routes types in bgpd. The following enhancements have been made:
* bgp_route.c:bgp_process_main_one() now sets implicit-null local_label to all local, aggregate and redistributed routes.
* bgp_route.c:bgp_process_main_one() now will request a label from the label pool for any prefix that loses the label for some reason (for example, when the static label assignment config is removed)
* bgp_label.c:bgp_reg_dereg_for_label() now requests labels from label pool for routes which have no associated label index
* zebra_mpls.c:zebra_mpls_fec_register() now expects both label and label_index from the calling function, one of which must be set to MPLS_INVALID_LABEL or MPLS_INVALID_LABEL_INDEX, based on this it will decide how to register the provided FEC.
Signed-off-by: Anton Degtyarev <anton@cumulusnetworks.com>
MPLS label pool backed by allocations from the zebra label manager.
A caller requests a label (e.g., in support of an "auto" label
specification in the CLI) via lp_get(), supplying a unique ID and
a callback function. The callback function is invoked at a later
time with the unique ID and a label value to inform the requestor
of the assigned label.
Requestors may release their labels back to the pool via lp_release().
The label pool is stocked with labels allocated by the zebra label
manager. The interaction with zebra is asynchronous so that bgpd
is not blocked while awaiting a label allocation from zebra.
The label pool implementation allows for bgpd operation before (or
without) zebra, and gracefully handles loss and reconnection of
zebra. Of course, before initial connection with zebra, no labels
are assigned to requestors. If the zebra connection is lost and
regained, callbacks to requestors will invalidate old assignments
and then assign new labels.
Signed-off-by: G. Paul Ziemba <paulz@labn.net>
