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| 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 /net/core | |
| parent | 2929ad29a3015120ab64c86f362fc2a590ceb69c (diff) | |
| download | linux-b39b5f411dcfce28ff954e5d6acb2c11be3cb0ec.tar.gz linux-b39b5f411dcfce28ff954e5d6acb2c11be3cb0ec.tar.bz2 linux-b39b5f411dcfce28ff954e5d6acb2c11be3cb0ec.zip | |
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 'net/core')
| -rw-r--r-- | net/core/filter.c | 36 |
1 files changed, 35 insertions, 1 deletions
diff --git a/net/core/filter.c b/net/core/filter.c index ea48ec789b5c..5fd5139e8638 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -5352,6 +5352,40 @@ static bool sk_filter_is_valid_access(int off, int size, return bpf_skb_is_valid_access(off, size, type, prog, info); } +static bool cg_skb_is_valid_access(int off, int size, + enum bpf_access_type type, + const struct bpf_prog *prog, + struct bpf_insn_access_aux *info) +{ + switch (off) { + case bpf_ctx_range(struct __sk_buff, tc_classid): + case bpf_ctx_range(struct __sk_buff, data_meta): + case bpf_ctx_range(struct __sk_buff, flow_keys): + return false; + } + if (type == BPF_WRITE) { + switch (off) { + case bpf_ctx_range(struct __sk_buff, mark): + case bpf_ctx_range(struct __sk_buff, priority): + case bpf_ctx_range_till(struct __sk_buff, cb[0], cb[4]): + break; + default: + return false; + } + } + + switch (off) { + case bpf_ctx_range(struct __sk_buff, data): + info->reg_type = PTR_TO_PACKET; + break; + case bpf_ctx_range(struct __sk_buff, data_end): + info->reg_type = PTR_TO_PACKET_END; + break; + } + + return bpf_skb_is_valid_access(off, size, type, prog, info); +} + static bool lwt_is_valid_access(int off, int size, enum bpf_access_type type, const struct bpf_prog *prog, @@ -7044,7 +7078,7 @@ const struct bpf_prog_ops xdp_prog_ops = { const struct bpf_verifier_ops cg_skb_verifier_ops = { .get_func_proto = cg_skb_func_proto, - .is_valid_access = sk_filter_is_valid_access, + .is_valid_access = cg_skb_is_valid_access, .convert_ctx_access = bpf_convert_ctx_access, }; |