Messages in this thread | | | From | Eddie Hao <> | Date | Sun, 15 Jul 2018 15:06:58 -0700 | Subject | Re: [PATCH] bpf: allow BPF programs access skb_shared_info->gso_segs field |
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Sorry, forgot to annotate the subject line with bpf-next.
On Sun, Jul 15, 2018 at 1:45 AM Eddie Hao <eddieh@google.com> wrote: > > This adds the ability to read gso_segs from a BPF program. This is useful > for user space monitoring systems to get gso_segs statistics for each > arbitrary group of flows defined by the BPF program. > > Signed-off-by: Eddie Hao <eddieh@google.com> > --- > include/uapi/linux/bpf.h | 1 + > net/core/filter.c | 9 +++++++++ > 2 files changed, 10 insertions(+) > > diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h > index b7db3261c62d..282085445616 100644 > --- a/include/uapi/linux/bpf.h > +++ b/include/uapi/linux/bpf.h > @@ -2266,6 +2266,7 @@ struct __sk_buff { > /* ... here. */ > > __u32 data_meta; > + unsigned short gso_segs; > }; > > struct bpf_tunnel_key { > diff --git a/net/core/filter.c b/net/core/filter.c > index b9ec916f4e3a..f17e249f3fbb 100644 > --- a/net/core/filter.c > +++ b/net/core/filter.c > @@ -5820,6 +5820,15 @@ static u32 bpf_convert_ctx_access(enum bpf_access_type type, > bpf_target_off(struct sock_common, > skc_num, 2, target_size)); > break; > + > + case offsetof(struct __sk_buff, gso_segs): > + BUILD_BUG_ON(FIELD_SIZEOF(struct skb_shared_info, gso_segs) != > + sizeof(unsigned short)); > + off = offsetof(struct sk_buff, end); > + off += offsetof(struct skb_shared_info, gso_segs); > + *insn++ = BPF_LDX_MEM(BPF_SIZEOF(unsigned short), si->dst_reg, > + si->src_reg, off); > + break; > } > > return insn - insn_buf; > -- > 2.18.0.203.gfac676dfb9-goog >
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