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| author |   Mauricio Vasquez B <mauricio.vasquez@polito.it> | 2018-10-18 15:16:25 +0200 |
|---|---|---|
| committer |   Alexei Starovoitov <ast@kernel.org> | 2018-10-19 13:24:31 -0700 |
| commit | f1a2e44a3aeccb3ff18d3ccc0b0203e70b95bd92 (patch) | |
| tree | 454766bd47fa6030b9e60c96da4536413e661fb7 /include/linux/bpf_types.h | |
| parent | bpf/verifier: add ARG_PTR_TO_UNINIT_MAP_VALUE (diff) | |
| download | wireguard-linux-f1a2e44a3aeccb3ff18d3ccc0b0203e70b95bd92.tar.xz wireguard-linux-f1a2e44a3aeccb3ff18d3ccc0b0203e70b95bd92.zip | |
bpf: add queue and stack maps
Queue/stack maps implement a FIFO/LIFO data storage for ebpf programs.
These maps support peek, pop and push operations that are exposed to eBPF
programs through the new bpf_map[peek/pop/push] helpers. Those operations
are exposed to userspace applications through the already existing
syscalls in the following way:
BPF_MAP_LOOKUP_ELEM -> peek
BPF_MAP_LOOKUP_AND_DELETE_ELEM -> pop
BPF_MAP_UPDATE_ELEM -> push
Queue/stack maps are implemented using a buffer, tail and head indexes,
hence BPF_F_NO_PREALLOC is not supported.
As opposite to other maps, queue and stack do not use RCU for protecting
maps values, the bpf_map[peek/pop] have a ARG_PTR_TO_UNINIT_MAP_VALUE
argument that is a pointer to a memory zone where to save the value of a
map. Basically the same as ARG_PTR_TO_UNINIT_MEM, but the size has not
be passed as an extra argument.
Our main motivation for implementing queue/stack maps was to keep track
of a pool of elements, like network ports in a SNAT, however we forsee
other use cases, like for exampling saving last N kernel events in a map
and then analysing from userspace.
Signed-off-by: Mauricio Vasquez B <mauricio.vasquez@polito.it>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'include/linux/bpf_types.h')
| -rw-r--r-- | include/linux/bpf_types.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/bpf_types.h b/include/linux/bpf_types.h index 7bad4e1947ed..44d9ab4809bd 100644 --- a/include/linux/bpf_types.h +++ b/include/linux/bpf_types.h @@ -69,3 +69,5 @@ BPF_MAP_TYPE(BPF_MAP_TYPE_XSKMAP, xsk_map_ops) BPF_MAP_TYPE(BPF_MAP_TYPE_REUSEPORT_SOCKARRAY, reuseport_array_ops) #endif #endif +BPF_MAP_TYPE(BPF_MAP_TYPE_QUEUE, queue_map_ops) +BPF_MAP_TYPE(BPF_MAP_TYPE_STACK, stack_map_ops) |