Re: [RFC nf-next v5 0/2] netfilter: bpf: support prog update

["D. Wythe" <alibuda@linux.alibaba.com>]

Just a reminder to avoid forgetting this patch by everyone. 🙂

Best wishes,
D. Wythe


On 1/2/24 2:11 PM, D. Wythe wrote:
> From: "D. Wythe" <alibuda@linux.alibaba.com>
>
> This patches attempt to implements updating of progs within
> bpf netfilter link, allowing user update their ebpf netfilter
> prog in hot update manner.
>
> Besides, a corresponding test case has been added to verify
> whether the update works.
> --
> v1:
> 1. remove unnecessary context, access the prog directly via rcu.
> 2. remove synchronize_rcu(), dealloc the nf_link via kfree_rcu.
> 3. check the dead flag during the update.
> --
> v1->v2:
> 1. remove unnecessary nf_prog, accessing nf_link->link.prog in direct.
> --
> v2->v3:
> 1. access nf_link->link.prog via rcu_dereference_raw to avoid warning.
> --
> v3->v4:
> 1. remove mutex for link update, as it is unnecessary and can be replaced
> by atomic operations.
> --
> v4->v5:
> 1. fix error retval check on cmpxhcg
>
> D. Wythe (2):
>    netfilter: bpf: support prog update
>    selftests/bpf: Add netfilter link prog update test
>
>   net/netfilter/nf_bpf_link.c                        | 50 ++++++++-----
>   .../bpf/prog_tests/netfilter_link_update_prog.c    | 83 ++++++++++++++++++++++
>   .../bpf/progs/test_netfilter_link_update_prog.c    | 24 +++++++
>   3 files changed, 141 insertions(+), 16 deletions(-)
>   create mode 100644 tools/testing/selftests/bpf/prog_tests/netfilter_link_update_prog.c
>   create mode 100644 tools/testing/selftests/bpf/progs/test_netfilter_link_update_prog.c
>