Hi Harald, > -----Original Message----- > From: Harald Welte <[email protected]> > Sent: wtorek, 22 lutego 2022 21:40 > To: Drewek, Wojciech <[email protected]> > Cc: Marcin Szycik <[email protected]>; [email protected]; > [email protected]; > [email protected]; [email protected]; [email protected]; [email protected]; > [email protected]; intel-wired- > [email protected] > Subject: Re: [PATCH net-next v7 3/7] gtp: Implement GTP echo request > > Hi Wojciech, > > On Tue, Feb 22, 2022 at 09:38:08AM +0000, Drewek, Wojciech wrote: > > > > I think either the Tx and the Rx ard triggered by / notified to userspace, > > > or you would also do periodic triggering of Tx in the kernel autonomously, > > > and process the responses. But at that point then you also need to think > > > about further consequences, such as counting the number of missed ECHO > > > RESP, > > > and then notify userspace if that condition "N out of M last responses > > > missed". > > > > > > > I thought that with the GTP device created from ip link, userspace > > would be unable to receive Echo Response (similar to Echo Request). > > If it's not the case than I will get rid of handling Echo Response in the > > next version. > > Well, userspace cannot 'receive' the ECHO response through the UDP socket as > the UDP socket is hidden in the kernel. I was thinking of the same mechanism > you introduce for transmit: You can trigger the Tx of GTP ECHO REQ via > netlink, > so why shouldn't you receive a notifiation about its completion also via > netlink?
How can we notify the userspace that the echo response was received? I thought that I implemented it with the dumpit callback. Is there a way to send msg to the userspace using generic netlink interface? > > Just don't think of it as sending an ECHO REQ via netlink, but triggering the > tx > and acknowledging the completion/reception of a related response. > > One of the advantages of the existing mechanism via 'socket is held in > userspace' > is that we don't have to jump through any such hoops or invent strange > interfaces: > The process can just send and receive the messages as usual via UDP socket > related > syscalls. > > -- > - Harald Welte <[email protected]> http://laforge.gnumonks.org/ > ============================================================================ > "Privacy in residential applications is a desirable marketing option." > (ETSI EN 300 175-7 Ch. A6)
