On Mon, Mar 20, 2023 at 11:13:03AM -0700, Stanislav Fomichev wrote: > On Sun, Mar 19, 2023 at 12:19 PM Cong Wang <xiyou.wangcong@xxxxxxxxx> wrote: > > > > From: Cong Wang <cong.wang@xxxxxxxxxxxxx> > > > > Currently there is no way to know which sockmap a socket has been added > > to from outside, especially for that a socket can be added to multiple > > sockmap's. We could dump this via socket diag, as shown below. > > > > Sample output: > > > > # ./iproute2/misc/ss -tnaie --bpf-map > > ESTAB 0 344329 127.0.0.1:1234 127.0.0.1:40912 ino:21098 sk:5 cgroup:/user.slice/user-0.slice/session-c1.scope <-> sockmap: 1 > > > > # bpftool map > > 1: sockmap flags 0x0 > > key 4B value 4B max_entries 2 memlock 4096B > > pids echo-sockmap(549) > > 4: array name pid_iter.rodata flags 0x480 > > key 4B value 4B max_entries 1 memlock 4096B > > btf_id 10 frozen > > pids bpftool(624) > > > > In the future, we could dump other sockmap related stats too, hence I > > make it a nested attribute. > > > > Cc: John Fastabend <john.fastabend@xxxxxxxxx> > > Cc: Jakub Sitnicki <jakub@xxxxxxxxxxxxxx> > > Signed-off-by: Cong Wang <cong.wang@xxxxxxxxxxxxx> > > Looks fine from my POW, will let others comment. > > One thing I still don't understand here: what is missing from the > socket iterators to implement this? Is it all the sk_psock_get magic? > I remember you dismissed Yonghong's suggestion on v1, but have you > actually tried it? I am very confused. So in order to figure out which sockmap a socket has been added to, I have to dump *all* sockmap's??? It seems you are suggesting to solve this with a more complex and unnecessary approach? Please tell me why, I am really lost, I don't even see there is a point to make here. > > Also: a test would be nice to have. I know you've tested it with the > iproute2, but having something regularly exercised by the ci seems > good to have (and not a ton of work). Sure, so where are the tests for socket diag? I don't see any within the tree: $ git grep INET_DIAG_SOCKOPT -- tools/ $ Note, this is not suitable for bpf selftests, because it is less relevant to bpf, much more relevant to socket diag. I thought this is obvious. Thanks.
