On Fri, Feb 14, 2025 at 11:48 PM Stanislav Fomichev <stfomichev@xxxxxxxxx> wrote: > > On 02/14, Jason Xing wrote: > > 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. > > Ah, sorry, I misread it as bpf options taking precedence over tcp ones; > ignore the suggestion about setsockopt cgroup prog. > > And yes, reusing the logic of TCP_RTO_MAX_MS looks better! Okay, then I will send a patch soon. BTW, which tree should this series go in? Should I use the prefix '[patch bpf-next]' or something else in the title? Thanks, Jason
