This series adds a new map type, devmap_hash, that works like the existing
devmap type, but using a hash-based indexing scheme. This is useful for the use
case where a devmap is indexed by ifindex (for instance for use with the routing
table lookup helper). For this use case, the regular devmap needs to be sized
after the maximum ifindex number, not the number of devices in it. A hash-based
indexing scheme makes it possible to size the map after the number of devices it
should contain instead.
This was previously part of my patch series that also turned the regular
bpf_redirect() helper into a map-based one; for this series I just pulled out
the patches that introduced the new map type.
Changelog:
v2:
- Split commit adding the new map type so uapi and tools changes are separate.
Changes to these patches since the previous series:
- Rebase on top of the other devmap changes (makes this one simpler!)
- Don't enforce key==val, but allow arbitrary indexes.
- Rename the type to devmap_hash to reflect the fact that it's just a hashmap
now.
---
Toke Høiland-Jørgensen (6):
include/bpf.h: Remove map_insert_ctx() stubs
xdp: Refactor devmap allocation code for reuse
uapi/bpf: Add new devmap_hash type
xdp: Add devmap_hash map type for looking up devices by hashed index
tools/libbpf_probes: Add new devmap_hash type
tools: Add definitions for devmap_hash map type
include/linux/bpf.h | 11 -
include/linux/bpf_types.h | 1
include/trace/events/xdp.h | 3
include/uapi/linux/bpf.h | 1
kernel/bpf/devmap.c | 325 ++++++++++++++++++++++++++-----
kernel/bpf/verifier.c | 2
net/core/filter.c | 9 +
tools/bpf/bpftool/map.c | 1
tools/include/uapi/linux/bpf.h | 1
tools/lib/bpf/libbpf_probes.c | 1
tools/testing/selftests/bpf/test_maps.c | 16 ++
11 files changed, 310 insertions(+), 61 deletions(-)
