From: Vivek Goyal <vgoyal@xxxxxxxxxx> Date: Tue, 15 Apr 2014 20:20:10 -0400 > On Tue, Apr 15, 2014 at 02:53:13PM -0700, Andy Lutomirski wrote: >> On Tue, Apr 15, 2014 at 2:15 PM, Vivek Goyal <vgoyal@xxxxxxxxxx> wrote: >> > This patch implements socket option SO_PASSCGROUP along the lines of >> > SO_PASSCRED. >> > >> > If SO_PASSCGROUP is set, then recvmsg() will get a control message >> > SCM_CGROUP which will contain the cgroup path of sender. This cgroup >> > belongs to first mounted hierarchy in the sytem. >> > >> > SCM_CGROUP control message can only be received and sender can not send >> > a SCM_CGROUP message. Kernel automatically generates one if receiver >> > chooses to receive one. >> > >> > This works both for unix stream and datagram sockets. >> > >> > cgroup information is passed only if either the sender or receiver has >> > SO_PASSCGROUP option set. This means for existing workloads they should >> > not see any significant performance impact of this change. >> >> This is odd. Shouldn't an SCM_CGROUP cmsg be generated when the >> receiver has SO_PASSCGROUP set and the sender passes SCM_CGROUP to >> sendmsg? > > How can receiver trust the cgroup info generated by sender. It needs to > be generated by kernel so that receiver can trust it. > > And if receiver needs to know cgroup of sender, receiver can just set > SO_PASSCGROUP on socket and receiver should get one SCM_CGROUP message > with each message received. I completely agree. -- To unsubscribe from this list: send the line "unsubscribe cgroups" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
