bpf, xdp: Make bpf_redirect_map() a map operation
Currently the bpf_redirect_map() implementation dispatches to the
correct map-lookup function via a switch-statement. To avoid the
dispatching, this change adds bpf_redirect_map() as a map
operation. Each map provides its bpf_redirect_map() version, and
correct function is automatically selected by the BPF verifier.
A nice side-effect of the code movement is that the map lookup
functions are now local to the map implementation files, which removes
one additional function call.
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20210308112907.559576-2-bjorn.topel@gmail.com
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 9fe90ce5..97eb0b2 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -5582,7 +5582,8 @@ record_func_map(struct bpf_verifier_env *env, struct bpf_call_arg_meta *meta,
func_id != BPF_FUNC_map_push_elem &&
func_id != BPF_FUNC_map_pop_elem &&
func_id != BPF_FUNC_map_peek_elem &&
- func_id != BPF_FUNC_for_each_map_elem)
+ func_id != BPF_FUNC_for_each_map_elem &&
+ func_id != BPF_FUNC_redirect_map)
return 0;
if (map == NULL) {
@@ -12017,7 +12018,8 @@ static int do_misc_fixups(struct bpf_verifier_env *env)
insn->imm == BPF_FUNC_map_delete_elem ||
insn->imm == BPF_FUNC_map_push_elem ||
insn->imm == BPF_FUNC_map_pop_elem ||
- insn->imm == BPF_FUNC_map_peek_elem)) {
+ insn->imm == BPF_FUNC_map_peek_elem ||
+ insn->imm == BPF_FUNC_redirect_map)) {
aux = &env->insn_aux_data[i + delta];
if (bpf_map_ptr_poisoned(aux))
goto patch_call_imm;
@@ -12059,6 +12061,9 @@ static int do_misc_fixups(struct bpf_verifier_env *env)
(int (*)(struct bpf_map *map, void *value))NULL));
BUILD_BUG_ON(!__same_type(ops->map_peek_elem,
(int (*)(struct bpf_map *map, void *value))NULL));
+ BUILD_BUG_ON(!__same_type(ops->map_redirect,
+ (int (*)(struct bpf_map *map, u32 ifindex, u64 flags))NULL));
+
patch_map_ops_generic:
switch (insn->imm) {
case BPF_FUNC_map_lookup_elem:
@@ -12085,6 +12090,10 @@ static int do_misc_fixups(struct bpf_verifier_env *env)
insn->imm = BPF_CAST_CALL(ops->map_peek_elem) -
__bpf_call_base;
continue;
+ case BPF_FUNC_redirect_map:
+ insn->imm = BPF_CAST_CALL(ops->map_redirect) -
+ __bpf_call_base;
+ continue;
}
goto patch_call_imm;
