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authorDaniel Borkmann <daniel@iogearbox.net>2016-09-23 01:28:37 +0200
committerDavid S. Miller <davem@davemloft.net>2016-09-23 08:40:28 -0400
commit7a4b28c6cc9ffac50f791b99cc7e46106436e5d8 (patch)
treea75242c2019c0a87017ca6babca3953c0b206e38 /net/core
parent669dc4d76d0ecc2d795df735839f43cfddf9f617 (diff)
downloadtalos-obmc-linux-7a4b28c6cc9ffac50f791b99cc7e46106436e5d8.tar.gz
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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>
Diffstat (limited to 'net/core')
-rw-r--r--net/core/filter.c18
1 files changed, 18 insertions, 0 deletions
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:
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