On Fri, Feb 14, 2025 at 7:41 AM Stanislav Fomichev <stfomichev@xxxxxxxxx> 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@xxxxxxxxx> > > --- > > 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. And > the precedence as well. 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. [1]: https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git/commit/?id=ae9b3c0e79bc > > WRT precedence, can you install setsockopt cgroup program and filter out > calls to TCP_RTO_MAX_MS? Yesterday, as suggested by Kuniyuki, I decided to re-use the same logic of TCP_RTO_MAX_MS for bpf_setsockopt(): diff --git a/net/core/filter.c b/net/core/filter.c index 2ec162dd83c4..ffec7b4357f9 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -5382,6 +5382,7 @@ static int sol_tcp_sockopt(struct sock *sk, int optname, case TCP_USER_TIMEOUT: case TCP_NOTSENT_LOWAT: case TCP_SAVE_SYN: + case TCP_RTO_MAX_MS: if (*optlen != sizeof(int)) return -EINVAL; break; Are you referring to using the previous way (by introducing a new flag for BPF) because we need to know the explicit precedence between setsockopt() and bpf_setsockopt() or other reasons? If so, I think there are more places than setsockopt() to modify. And, sorry that I don't follow what you meant by saying "install setsockopt cgroup program" here. Please provide more hints. Thanks for the review:) Thanks, Jason
