The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.
Discussed with: pfg
MFC After: 3 days
Sponsored by: Netflix
When a prefix gets deleted from the RIB, dpdk_lpm algo needs to know
the nexthop of the "parent" prefix to update its internal state.
The glue code, which utilises RIB as a backing route store, uses
fib[46]_lookup_rt() for the prefix destination after its deletion
to fetch the desired nexthop.
This approach does not work when deleting less-specific prefixes
with most-specific ones are still present. For example, if
10.0.0.0/24, 10.0.0.0/23 and 10.0.0.0/22 exist in RIB, deleting
10.0.0.0/23 would result in 10.0.0.0/24 being returned as a search
result instead of 10.0.0.0/22. This, in turn, results in the failed
datastructure update: part of the deleted /23 prefix will still
contain the reference to an old nexthop. This leads to the
use-after-free behaviour, ending with the eventual crashes.
Fix the logic flaw by properly fetching the prefix "parent" via
newly-created rt_get_inet[6]_parent() helpers.
Differential Revision: https://reviews.freebsd.org/D31546
PR: 256882,256833
MFC after: 1 week
The current preference number were copied from IPv4 code,
assuming 500k routes to be the full-view. Adjust with the current
reality (100k full-view).
Reported by: Marek Zarychta <zarychtam at plan-b.pwste.edu.pl>
MFC after: 3 days
This change introduces loadable fib lookup modules based on
DPDK rte_lpm lib targeted for high-speed lookups in large-scale tables.
It is based on the lookup framework described in D27401.
IPv4 module is called dpdk_lpm4. It wraps around rte_lpm [1] library.
This library implements variation of DIR24-8 [2] lookup algorithm.
Module provide lockless route lookups and in-place incremental updates,
allowing for good RIB performance.
IPv6 module is called dpdk_lpm6. It wraps around rte_lpm6 [3] library.
Implementation can be seen as multi-bit trie where the stride or number of bits
inspected on each level varies from level to level.
It can vary from 1 to 14 memory accesses, with 5 being the average value
for the lengths that are most commonly used in IPv6.
Module provide lockless route lookups for global unicast addresses
and in-place incremental updates, allowing for good RIB performance.
Implementation details:
* wrapper code lives in `sys/contrib/dpdk_rte_lpm/dpdk_lpm[6].c`.
* rte_lpm[6] implementation contains both RIB and FIB code.
. RIB ("rule_") code, backed by array of hash tables part has been commented out,
as base radix already provides all the necessary primitives.
* link-local lookups are currently implemented as base radix lookup.
This part should be converted to something like read-only radix trie.
Usage detail:
Compile kernel with option FIB_ALGO and load dpdk_lpm4/dpdk_lpm6
module at any time. They will be picked up automatically when
amount of routes raises to several thousand.
[1]: https://doc.dpdk.org/guides/prog_guide/lpm_lib.html
[2]: http://yuba.stanford.edu/~nickm/papers/Infocom98_lookup.pdf
[3]: https://doc.dpdk.org/guides/prog_guide/lpm6_lib.html
Differential Revision: https://reviews.freebsd.org/D27412
