diff options
| author | Daniel Borkmann <daniel@iogearbox.net> | 2016-09-23 01:28:37 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-09-23 08:40:28 -0400 |
| commit | 7a4b28c6cc9ffac50f791b99cc7e46106436e5d8 (patch) | |
| tree | a75242c2019c0a87017ca6babca3953c0b206e38 | |
| parent | 669dc4d76d0ecc2d795df735839f43cfddf9f617 (diff) | |
bpf: add helper to invalidate hash
Add a small helper that complements 36bbef52c7eb ("bpf: direct packet
write and access for helpers for clsact progs") for invalidating the
current skb->hash after mangling on headers via direct packet write.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | include/uapi/linux/bpf.h | 7 | ||||
| -rw-r--r-- | net/core/filter.c | 18 |
2 files changed, 25 insertions, 0 deletions
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index e07432b9f8b8..f09c70b97eca 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -419,6 +419,13 @@ enum bpf_func_id { */ BPF_FUNC_csum_update, + /** + * bpf_set_hash_invalid(skb) + * Invalidate current skb>hash. + * @skb: pointer to skb + */ + BPF_FUNC_set_hash_invalid, + __BPF_FUNC_MAX_ID, }; diff --git a/net/core/filter.c b/net/core/filter.c index acf84fbfb043..00351cdf7d0c 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -1777,6 +1777,22 @@ static const struct bpf_func_proto bpf_get_hash_recalc_proto = { .arg1_type = ARG_PTR_TO_CTX, }; +BPF_CALL_1(bpf_set_hash_invalid, struct sk_buff *, skb) +{ + /* After all direct packet write, this can be used once for + * triggering a lazy recalc on next skb_get_hash() invocation. + */ + skb_clear_hash(skb); + return 0; +} + +static const struct bpf_func_proto bpf_set_hash_invalid_proto = { + .func = bpf_set_hash_invalid, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, +}; + BPF_CALL_3(bpf_skb_vlan_push, struct sk_buff *, skb, __be16, vlan_proto, u16, vlan_tci) { @@ -2534,6 +2550,8 @@ tc_cls_act_func_proto(enum bpf_func_id func_id) return &bpf_get_route_realm_proto; case BPF_FUNC_get_hash_recalc: return &bpf_get_hash_recalc_proto; + case BPF_FUNC_set_hash_invalid: + return &bpf_set_hash_invalid_proto; case BPF_FUNC_perf_event_output: return &bpf_skb_event_output_proto; case BPF_FUNC_get_smp_processor_id: |