diff options
| author | Song Liu <songliubraving@fb.com> | 2018-10-19 09:57:57 -0700 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2018-10-19 13:49:34 -0700 |
| commit | b39b5f411dcfce28ff954e5d6acb2c11be3cb0ec (patch) | |
| tree | 4f724a3269469e76ed30c674bf52ddef3fb93db0 /include | |
| parent | 2929ad29a3015120ab64c86f362fc2a590ceb69c (diff) | |
bpf: add cg_skb_is_valid_access for BPF_PROG_TYPE_CGROUP_SKB
BPF programs of BPF_PROG_TYPE_CGROUP_SKB need to access headers in the
skb. This patch enables direct access of skb for these programs.
Two helper functions bpf_compute_and_save_data_end() and
bpf_restore_data_end() are introduced. There are used in
__cgroup_bpf_run_filter_skb(), to compute proper data_end for the
BPF program, and restore original data afterwards.
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/filter.h | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/include/linux/filter.h b/include/linux/filter.h index 5771874bc01e..91b4c934f02e 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -548,6 +548,27 @@ static inline void bpf_compute_data_pointers(struct sk_buff *skb) cb->data_end = skb->data + skb_headlen(skb); } +/* Similar to bpf_compute_data_pointers(), except that save orginal + * data in cb->data and cb->meta_data for restore. + */ +static inline void bpf_compute_and_save_data_end( + struct sk_buff *skb, void **saved_data_end) +{ + struct bpf_skb_data_end *cb = (struct bpf_skb_data_end *)skb->cb; + + *saved_data_end = cb->data_end; + cb->data_end = skb->data + skb_headlen(skb); +} + +/* Restore data saved by bpf_compute_data_pointers(). */ +static inline void bpf_restore_data_end( + struct sk_buff *skb, void *saved_data_end) +{ + struct bpf_skb_data_end *cb = (struct bpf_skb_data_end *)skb->cb; + + cb->data_end = saved_data_end; +} + static inline u8 *bpf_skb_cb(struct sk_buff *skb) { /* eBPF programs may read/write skb->cb[] area to transfer meta |