diff options
| author | Martin KaFai Lau <kafai@fb.com> | 2016-12-07 15:53:11 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-12-08 14:25:13 -0500 |
| commit | 17bedab2723145d17b14084430743549e6943d03 (patch) | |
| tree | 6a1517e36c1be543f591b5ff7fcd7e816dcc906a /include | |
| parent | 8a03cf2cb7efe269913db079afb8c31f20bf0bef (diff) | |
bpf: xdp: Allow head adjustment in XDP prog
This patch allows XDP prog to extend/remove the packet
data at the head (like adding or removing header). It is
done by adding a new XDP helper bpf_xdp_adjust_head().
It also renames bpf_helper_changes_skb_data() to
bpf_helper_changes_pkt_data() to better reflect
that XDP prog does not work on skb.
This patch adds one "xdp_adjust_head" bit to bpf_prog for the
XDP-capable driver to check if the XDP prog requires
bpf_xdp_adjust_head() support. The driver can then decide
to error out during XDP_SETUP_PROG.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/filter.h | 6 | ||||
| -rw-r--r-- | include/uapi/linux/bpf.h | 11 |
2 files changed, 14 insertions, 3 deletions
diff --git a/include/linux/filter.h b/include/linux/filter.h index f078d2b1cff6..6a1658308612 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -406,7 +406,8 @@ struct bpf_prog { u16 jited:1, /* Is our filter JIT'ed? */ gpl_compatible:1, /* Is filter GPL compatible? */ cb_access:1, /* Is control block accessed? */ - dst_needed:1; /* Do we need dst entry? */ + dst_needed:1, /* Do we need dst entry? */ + xdp_adjust_head:1; /* Adjusting pkt head? */ kmemcheck_bitfield_end(meta); enum bpf_prog_type type; /* Type of BPF program */ u32 len; /* Number of filter blocks */ @@ -440,6 +441,7 @@ struct bpf_skb_data_end { struct xdp_buff { void *data; void *data_end; + void *data_hard_start; }; /* compute the linear packet data range [data, data_end) which @@ -595,7 +597,7 @@ void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp); u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog); -bool bpf_helper_changes_skb_data(void *func); +bool bpf_helper_changes_pkt_data(void *func); struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off, const struct bpf_insn *patch, u32 len); diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 6123d9b8e828..0eb0e87dbe9f 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -424,6 +424,12 @@ union bpf_attr { * @len: length of header to be pushed in front * @flags: Flags (unused for now) * Return: 0 on success or negative error + * + * int bpf_xdp_adjust_head(xdp_md, delta) + * Adjust the xdp_md.data by delta + * @xdp_md: pointer to xdp_md + * @delta: An positive/negative integer to be added to xdp_md.data + * Return: 0 on success or negative on error */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -469,7 +475,8 @@ union bpf_attr { FN(csum_update), \ FN(set_hash_invalid), \ FN(get_numa_node_id), \ - FN(skb_change_head), + FN(skb_change_head), \ + FN(xdp_adjust_head), /* integer value in 'imm' field of BPF_CALL instruction selects which helper * function eBPF program intends to call @@ -576,6 +583,8 @@ struct bpf_sock { __u32 protocol; }; +#define XDP_PACKET_HEADROOM 256 + /* User return codes for XDP prog type. * A valid XDP program must return one of these defined values. All other * return codes are reserved for future use. Unknown return codes will result |