diff options
| author | Daniel Borkmann <daniel@iogearbox.net> | 2017-07-02 02:13:26 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-07-03 02:22:52 -0700 |
| commit | 2be7e212d5419a400d051c84ca9fdd083e5aacac (patch) | |
| tree | 5787a57531550094941e58800517df911788562e /include | |
| parent | 0daf4349406074fc03e4889ba5e97e6fb5311bab (diff) | |
| download | lwn-2be7e212d5419a400d051c84ca9fdd083e5aacac.tar.gz lwn-2be7e212d5419a400d051c84ca9fdd083e5aacac.zip | |
bpf: add bpf_skb_adjust_room helper
This work adds a helper that can be used to adjust net room of an
skb. The helper is generic and can be further extended in future.
Main use case is for having a programmatic way to add/remove room to
v4/v6 header options along with cls_bpf on egress and ingress hook
of the data path. It reuses most of the infrastructure that we added
for the bpf_skb_change_type() helper which can be used in nat64
translations. Similarly, the helper only takes care of adjusting the
room so that related data is populated and csum adapted out of the
BPF program using it.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include')
| -rw-r--r-- | include/uapi/linux/bpf.h | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index a6a91e5e96fc..e99e3e6f8b37 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -531,6 +531,14 @@ union bpf_attr { * @optval: pointer to option value * @optlen: length of optval in byes * Return: 0 or negative error + * + * int bpf_skb_adjust_room(skb, len_diff, mode, flags) + * Grow or shrink room in sk_buff. + * @skb: pointer to skb + * @len_diff: (signed) amount of room to grow/shrink + * @mode: operation mode (enum bpf_adj_room_mode) + * @flags: reserved for future use + * Return: 0 on success or negative error code */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -582,7 +590,8 @@ union bpf_attr { FN(get_socket_cookie), \ FN(get_socket_uid), \ FN(set_hash), \ - FN(setsockopt), + FN(setsockopt), \ + FN(skb_adjust_room), /* integer value in 'imm' field of BPF_CALL instruction selects which helper * function eBPF program intends to call @@ -632,6 +641,11 @@ enum bpf_func_id { /* BPF_FUNC_perf_event_output for sk_buff input context. */ #define BPF_F_CTXLEN_MASK (0xfffffULL << 32) +/* Mode for BPF_FUNC_skb_adjust_room helper. */ +enum bpf_adj_room_mode { + BPF_ADJ_ROOM_NET, +}; + /* user accessible mirror of in-kernel sk_buff. * new fields can only be added to the end of this structure */ |