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authorMauricio Vasquez B <mauricio.vasquez@polito.it>2018-10-18 15:16:25 +0200
committerAlexei Starovoitov <ast@kernel.org>2018-10-19 13:24:31 -0700
commitf1a2e44a3aeccb3ff18d3ccc0b0203e70b95bd92 (patch)
tree454766bd47fa6030b9e60c96da4536413e661fb7 /net
parent2ea864c58f19bf70a0e2415f9f1c53814e07f1b4 (diff)
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 'net')
-rw-r--r--net/core/filter.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/net/core/filter.c b/net/core/filter.c
index 1a3ac6c46873..ea48ec789b5c 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -4876,6 +4876,12 @@ bpf_base_func_proto(enum bpf_func_id func_id)
return &bpf_map_update_elem_proto;
case BPF_FUNC_map_delete_elem:
return &bpf_map_delete_elem_proto;
+ case BPF_FUNC_map_push_elem:
+ return &bpf_map_push_elem_proto;
+ case BPF_FUNC_map_pop_elem:
+ return &bpf_map_pop_elem_proto;
+ case BPF_FUNC_map_peek_elem:
+ return &bpf_map_peek_elem_proto;
case BPF_FUNC_get_prandom_u32:
return &bpf_get_prandom_u32_proto;
case BPF_FUNC_get_smp_processor_id: