Re: [PATCH] Add skb_store_bytes() for BPF_PROG_TYPE_CGROUP_SKB
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From: Yonghong Song <hidden>
Date: 2021-12-22 03:44:04
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bpf
On 12/21/21 6:27 PM, Tyler Wear wrote:
Need to modify the ds field to support upcoming Wifi QoS Alliance spec. Instead of adding generic function for just modifying the ds field, add skb_store_bytes for BPF_PROG_TYPE_CGROUP_SKB. This allows other fields in the network and transport header to be modified in the future.
Could change tag from "[PATCH]" to "[PATCH bpf-next]"? Please also indicate the version of the patch, so in this case, it should be "[PATCH bpf-next v2]". I think you can add more contents in the commit message about why existing bpf_setsockopt() won't work and why CGROUP_UDP[4|6]_SENDMSG is not preferred. These have been discussed in v1 of this patch and they are valuable for people to understand full context and reasoning.
quoted hunk ↗ jump to hunk
Signed-off-by: Tyler Wear <redacted> --- net/core/filter.c | 2 ++ 1 file changed, 2 insertions(+)diff --git a/net/core/filter.c b/net/core/filter.c index 6102f093d59a..0c25aa2212a2 100644 --- a/net/core/filter.c +++ b/net/core/filter.c@@ -7289,6 +7289,8 @@ static const struct bpf_func_proto * cg_skb_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) { switch (func_id) { + case BPF_FUNC_skb_store_bytes: + return &bpf_skb_store_bytes_proto;
Typically different 'case's are added in chronological order to people can guess what is added earlier and what is added later. Maybe add the new helper after BPF_FUNC_perf_event_output?
case BPF_FUNC_get_local_storage: return &bpf_get_local_storage_proto; case BPF_FUNC_sk_fullsock:
Please add a test case to exercise the new usage of bpf_skb_store_bytes() helper. You may piggy back on some existing cg_skb progs if it is easier to do.