Re: [PATCH net-next 2/3] bpf: add TCP_BPF_RTO_MAX for bpf_setsockopt

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

On 2/13/25 3:57 PM, Jason Xing wrote:
> On Fri, Feb 14, 2025 at 7:41 AM Stanislav Fomichev<stfomichev@gmail.com> wrote:
>> On 02/13, Jason Xing wrote:
>>> Support bpf_setsockopt() to set the maximum value of RTO for
>>> BPF program.
>>>
>>> Signed-off-by: Jason Xing<kerneljasonxing@gmail.com>
>>> ---
>>>   Documentation/networking/ip-sysctl.rst | 3 ++-
>>>   include/uapi/linux/bpf.h               | 2 ++
>>>   net/core/filter.c                      | 6 ++++++
>>>   tools/include/uapi/linux/bpf.h         | 2 ++
>>>   4 files changed, 12 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/Documentation/networking/ip-sysctl.rst b/Documentation/networking/ip-sysctl.rst
>>> index 054561f8dcae..78eb0959438a 100644
>>> --- a/Documentation/networking/ip-sysctl.rst
>>> +++ b/Documentation/networking/ip-sysctl.rst
>>> @@ -1241,7 +1241,8 @@ tcp_rto_min_us - INTEGER
>>>
>>>   tcp_rto_max_ms - INTEGER
>>>        Maximal TCP retransmission timeout (in ms).
>>> -     Note that TCP_RTO_MAX_MS socket option has higher precedence.
>>> +     Note that TCP_BPF_RTO_MAX and TCP_RTO_MAX_MS socket option have the
>>> +     higher precedence for configuring this setting.
>> The cover letter needs more explanation about the motivation.

+1

I haven't looked at the patches. The cover letter has no word on the use case. 
Using test_tcp_hdr_options.c as the test is unnecessarily complicated just for 
adding a new optname support. setget_sockopt.c is the right test to reuse.


> I am targeting the net-next tree because of recent changes[1] made by
> Eric. It probably hasn't merged into the bpf-next tree.

There is the bpf-next/net tree. It should have the needed changes.

pw-bot: cr