Re: [PATCH bpf-next v12 01/12] bpf: add networking timestamping support to bpf_get/setsockopt()

[Martin KaFai Lau <martin.lau@linux.dev>]

On 2/18/25 11:03 PM, Jason Xing wrote:
> On Tue, Feb 18, 2025 at 1:02 PM Jason Xing <kerneljasonxing@gmail.com> wrote:
>>
>> The new SK_BPF_CB_FLAGS and new SK_BPF_CB_TX_TIMESTAMPING are
>> added to bpf_get/setsockopt. The later patches will implement the
>> BPF networking timestamping. The BPF program will use
>> bpf_setsockopt(SK_BPF_CB_FLAGS, SK_BPF_CB_TX_TIMESTAMPING) to
>> enable the BPF networking timestamping on a socket.
>>
>> Signed-off-by: Jason Xing <kerneljasonxing@gmail.com>
>> ---
>>   include/net/sock.h             |  3 +++
>>   include/uapi/linux/bpf.h       |  8 ++++++++
>>   net/core/filter.c              | 23 +++++++++++++++++++++++
>>   tools/include/uapi/linux/bpf.h |  1 +
>>   4 files changed, 35 insertions(+)
>>
>> diff --git a/include/net/sock.h b/include/net/sock.h
>> index 8036b3b79cd8..7916982343c6 100644
>> --- a/include/net/sock.h
>> +++ b/include/net/sock.h
>> @@ -303,6 +303,7 @@ struct sk_filter;
>>     *    @sk_stamp: time stamp of last packet received
>>     *    @sk_stamp_seq: lock for accessing sk_stamp on 32 bit architectures only
>>     *    @sk_tsflags: SO_TIMESTAMPING flags
>> +  *    @sk_bpf_cb_flags: used in bpf_setsockopt()
>>     *    @sk_use_task_frag: allow sk_page_frag() to use current->task_frag.
>>     *                       Sockets that can be used under memory reclaim should
>>     *                       set this to false.
>> @@ -445,6 +446,8 @@ struct sock {
>>          u32                     sk_reserved_mem;
>>          int                     sk_forward_alloc;
>>          u32                     sk_tsflags;
>> +#define SK_BPF_CB_FLAG_TEST(SK, FLAG) ((SK)->sk_bpf_cb_flags & (FLAG))
>> +       u32                     sk_bpf_cb_flags;
>>          __cacheline_group_end(sock_write_rxtx);
>>
>>          __cacheline_group_begin(sock_write_tx);
>> diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
>> index fff6cdb8d11a..fa666d51dffe 100644
>> --- a/include/uapi/linux/bpf.h
>> +++ b/include/uapi/linux/bpf.h
>> @@ -6916,6 +6916,13 @@ enum {
>>          BPF_SOCK_OPS_ALL_CB_FLAGS       = 0x7F,
>>   };
>>
>> +/* Definitions for bpf_sk_cb_flags */
> 
> nit: s/bpf_sk_cb_flags/sk_bpf_cb_flags
> 
> I will correct it.
> 
>> +enum {
>> +       SK_BPF_CB_TX_TIMESTAMPING       = 1<<0,
>> +       SK_BPF_CB_MASK                  = (SK_BPF_CB_TX_TIMESTAMPING - 1) |
>> +                                          SK_BPF_CB_TX_TIMESTAMPING
>> +};
> 
> Martin, I would like to know if it's necessary to update the above new
> enum in tools/include/uapi/linux/bpf.h as well?

Yes, the tools/include/uapi/linux/bpf.h should be updated. If you diff them, two 
of them should be exactly the same. This patch should do the same to keep the 
tools bpf.h up-to-date.

For other headers in tools/include/uapi, I guess it depends. e.g. the tcp.h in 
your another RTO patch, the two tcp.h files are very different already and the 
selftest does not need the new macro either.