Re: [PATCH 0/2] namespaces: log namespaces per task

Le 02/05/2014 16:28, Richard Guy Briggs a ?crit : >On 14/05/02, Serge E. Hallyn wrote: >>Quoting Richard Guy Briggs (rgb(a)redhat.com): >>>I saw no replies to my questions when I replied a year after Aris' posting, so >>>I don't know if it was ignored or got lost in stale threads: >>> https://www.redhat.com/archives/linux-audit/2013-March/msg00020.html >>> https://www.redhat.com/archives/linux-audit/2013-March/msg00033.html >>> (https://lists.linux-foundation.org/pipermail/containers/2013-March/032063...) >>> https://www.redhat.com/archives/linux-audit/2014-January/msg00180.html >>> >>>I've tried to answer a number of questions that were raised in that thread. >>> >>>The goal is not quite identical to Aris' patchset. >>> >>>The purpose is to track namespaces in use by logged processes from the >>>perspective of init_*_ns. The first patch defines a function to list them. >>>The second patch provides an example of usage for audit_log_task_info() which >>>is used by syscall audits, among others. audit_log_task() and >>>audit_common_recv_message() would be other potential use cases. >>> >>>Use a serial number per namespace (unique across one boot of one kernel) >>>instead of the inode number (which is claimed to have had the right to change >>>reserved and is not necessarily unique if there is more than one proc fs). It >>>could be argued that the inode numbers have now become a defacto interface and >>>can't change now, but I'm proposing this approach to see if this helps address >>>some of the objections to the earlier patchset. >>> >>>There could also have messages added to track the creation and the destruction >>>of namespaces, listing the parent for hierarchical namespaces such as pidns, >>>userns, and listing other ids for non-hierarchical namespaces, as well as other >>>information to help identify a namespace. >>> >>>There has been some progress made for audit in net namespaces and pid >>>namespaces since this previous thread. net namespaces are now served as peers >>>by one auditd in the init_net namespace with processes in a non-init_net >>>namespace being able to write records if they are in the init_user_ns and have >>>CAP_AUDIT_WRITE. Processes in a non-init_pid_ns can now similarly write >>>records. As for CAP_AUDIT_READ, I just posted a patchset to check capabilities >>>of userspace processes that try to join netlink broadcast groups. >>> >>> >>>Questions: >>>Is there a way to link serial numbers of namespaces involved in migration of a >>>container to another kernel? (I had a brief look at CRIU.) Is there a unique >>>identifier for each running instance of a kernel? Or at least some identifier >>>within the container migration realm? >> >>Eric Biederman has always been adamantly opposed to adding new namespaces >>of namespaces, so the fact that you're asking this question concerns me. > >I have seen that position and I don't fully understand the justification >for it other than added complexity. Just FYI, have you seen this thread: http://thread.gmane.org/gmane.linux.network/286572/ There is some explanations/examples about this topic.

Nicolas