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

On 14/05/05, Nicolas Dichtel wrote: > 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. Thanks for that reference. I read it through, but will need to do so again to get it to sink in.