2019-06-06 23:30:49

by Roman Gushchin

Subject: [PATCH bpf-next] bpf: allow CGROUP_SKB programs to use bpf_skb_cgroup_id() helper

Currently bpf_skb_cgroup_id() is not supported for CGROUP_SKB
programs. An attempt to load such a program generates an error
like this:

libbpf:
0: (b7) r6 = 0
...
9: (85) call bpf_skb_cgroup_id#79
unknown func bpf_skb_cgroup_id#79

There are no particular reasons for denying it, and we have some
use cases where it might be useful.

So let's add it to the list of allowed helpers.

Signed-off-by: Roman Gushchin <[email protected]>
Cc: Yonghong Song <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Daniel Borkmann <[email protected]>
---
net/core/filter.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/net/core/filter.c b/net/core/filter.c
index 55bfc941d17a..f2777dc0b624 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -5919,6 +5919,10 @@ cg_skb_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
return &bpf_sk_storage_get_proto;
case BPF_FUNC_sk_storage_delete:
return &bpf_sk_storage_delete_proto;
+#ifdef CONFIG_SOCK_CGROUP_DATA
+ case BPF_FUNC_skb_cgroup_id:
+ return &bpf_skb_cgroup_id_proto;
+#endif
#ifdef CONFIG_INET
case BPF_FUNC_tcp_sock:
return &bpf_tcp_sock_proto;
--
2.20.1

2019-06-07 00:52:53

by Roman Gushchin

Subject: Re: [PATCH bpf-next] bpf: allow CGROUP_SKB programs to use bpf_skb_cgroup_id() helper

On Fri, Jun 07, 2019 at 02:00:20AM +0200, Daniel Borkmann wrote:
> On 06/06/2019 10:30 PM, Roman Gushchin wrote:
> > Currently bpf_skb_cgroup_id() is not supported for CGROUP_SKB
> > programs. An attempt to load such a program generates an error
> > like this:
> >
> > libbpf:
> > 0: (b7) r6 = 0
> > ...
> > 9: (85) call bpf_skb_cgroup_id#79
> > unknown func bpf_skb_cgroup_id#79
> >
> > There are no particular reasons for denying it, and we have some
> > use cases where it might be useful.
> >
> > So let's add it to the list of allowed helpers.
> >
> > Signed-off-by: Roman Gushchin <[email protected]>
> > Cc: Yonghong Song <[email protected]>
> > Cc: Alexei Starovoitov <[email protected]>
> > Cc: Daniel Borkmann <[email protected]>
>
> Applied, thanks!

Thank you, Daniel!

2019-06-07 01:15:44

by Martin KaFai Lau

Subject: Re: [PATCH bpf-next] bpf: allow CGROUP_SKB programs to use bpf_skb_cgroup_id() helper

On Thu, Jun 06, 2019 at 01:30:12PM -0700, Roman Gushchin wrote:
> Currently bpf_skb_cgroup_id() is not supported for CGROUP_SKB
> programs. An attempt to load such a program generates an error
> like this:
>
> libbpf:
> 0: (b7) r6 = 0
> ...
> 9: (85) call bpf_skb_cgroup_id#79
> unknown func bpf_skb_cgroup_id#79
>
> There are no particular reasons for denying it, and we have some
> use cases where it might be useful.
>
> So let's add it to the list of allowed helpers.
Acked-by: Martin KaFai Lau <[email protected]>

2019-06-07 02:07:23

by Daniel Borkmann

Subject: Re: [PATCH bpf-next] bpf: allow CGROUP_SKB programs to use bpf_skb_cgroup_id() helper

On 06/06/2019 10:30 PM, Roman Gushchin wrote:
> Currently bpf_skb_cgroup_id() is not supported for CGROUP_SKB
> programs. An attempt to load such a program generates an error
> like this:
>
> libbpf:
> 0: (b7) r6 = 0
> ...
> 9: (85) call bpf_skb_cgroup_id#79
> unknown func bpf_skb_cgroup_id#79
>
> There are no particular reasons for denying it, and we have some
> use cases where it might be useful.
>
> So let's add it to the list of allowed helpers.
>
> Signed-off-by: Roman Gushchin <[email protected]>
> Cc: Yonghong Song <[email protected]>
> Cc: Alexei Starovoitov <[email protected]>
> Cc: Daniel Borkmann <[email protected]>

Applied, thanks!