diff options
| author | Daniel Borkmann | 2017-01-24 01:06:28 +0100 |
|---|---|---|
| committer | David S. Miller | 2017-01-24 20:46:06 +0100 |
| commit | d1b662adcdb87944b7f6f7bd2f95cbb1404dbf18 (patch) | |
| tree | ce847a4583aff07f03b6218180915d066949d403 | |
| parent | bpf: enable load bytes helper for filter/reuseport progs (diff) | |
| download | kernel-qcow2-linux-d1b662adcdb87944b7f6f7bd2f95cbb1404dbf18.tar.gz kernel-qcow2-linux-d1b662adcdb87944b7f6f7bd2f95cbb1404dbf18.tar.xz kernel-qcow2-linux-d1b662adcdb87944b7f6f7bd2f95cbb1404dbf18.zip | |
bpf: allow option for setting bpf_l4_csum_replace from scratch
When programs need to calculate the csum from scratch for small UDP
packets and use bpf_l4_csum_replace() to feed the result from helpers
like bpf_csum_diff(), then we need a flag besides BPF_F_MARK_MANGLED_0
that would ignore the case of current csum being 0, and which would
still allow for the helper to set the csum and transform when needed
to CSUM_MANGLED_0.
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 | 1 | ||||
| -rw-r--r-- | net/core/filter.c | 7 |
2 files changed, 5 insertions, 3 deletions
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index bd3068485410..e07fd5a324e6 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -522,6 +522,7 @@ enum bpf_func_id { /* BPF_FUNC_l4_csum_replace flags. */ #define BPF_F_PSEUDO_HDR (1ULL << 4) #define BPF_F_MARK_MANGLED_0 (1ULL << 5) +#define BPF_F_MARK_ENFORCE (1ULL << 6) /* BPF_FUNC_clone_redirect and BPF_FUNC_redirect flags. */ #define BPF_F_INGRESS (1ULL << 0) diff --git a/net/core/filter.c b/net/core/filter.c index e2263da505be..1e00737e3bc3 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -1522,10 +1522,11 @@ BPF_CALL_5(bpf_l4_csum_replace, struct sk_buff *, skb, u32, offset, { bool is_pseudo = flags & BPF_F_PSEUDO_HDR; bool is_mmzero = flags & BPF_F_MARK_MANGLED_0; + bool do_mforce = flags & BPF_F_MARK_ENFORCE; __sum16 *ptr; - if (unlikely(flags & ~(BPF_F_MARK_MANGLED_0 | BPF_F_PSEUDO_HDR | - BPF_F_HDR_FIELD_MASK))) + if (unlikely(flags & ~(BPF_F_MARK_MANGLED_0 | BPF_F_MARK_ENFORCE | + BPF_F_PSEUDO_HDR | BPF_F_HDR_FIELD_MASK))) return -EINVAL; if (unlikely(offset > 0xffff || offset & 1)) return -EFAULT; @@ -1533,7 +1534,7 @@ BPF_CALL_5(bpf_l4_csum_replace, struct sk_buff *, skb, u32, offset, return -EFAULT; ptr = (__sum16 *)(skb->data + offset); - if (is_mmzero && !*ptr) + if (is_mmzero && !do_mforce && !*ptr) return 0; switch (flags & BPF_F_HDR_FIELD_MASK) { |