Re: [PATCH 0/9] Add namespace support for syslog v2

[Gu Zheng <guz.fnst-BthXqXjhjHXQFUHtdCDX3A@public.gmane.org>]

Hi Rui,

On 07/29/2013 10:31 AM, Rui Xiang wrote:

> This patchset introduces a system log namespace.
> 
> It is the 2nd version. The link of the 1st version is 
> http://lwn.net/Articles/525728/. In that version, syslog_
> namespace was added into nsproxy and created through a new
> clone flag CLONE_SYSLOG when cloning a process. 
> 
> There were some discussion in last November about the 1st 
> version. This version used these important advice, and 
> referred to Serge's patch(http://lwn.net/Articles/525629/).
> 
> Unlike the 1st version, in this patchset, syslog namespace 
> is tied to a user namespace. Add we must create a new user 
> ns before create a new syslog ns, because that will make 
> users have full capabilities in this new userns after 
> cloning a new user ns. The syslog namespace can be created 
> through a new command(11) to __NR_syslog syscall. That owe 
> to a new syslog flag SYSLOG_ACTION_NEW_NS.
> 
> In syslog_namespace, some necessary identifiers for handling 
> syslog buf are containerized. When one container creates a
> new syslog ns, individual buf will be allocated to store log
> ownned this container. 
> 
> A new interface ns_printk is added to print the logs which 
> we want to see in the container. Through ns_printk, we can 
> get more logs related to a specific net ns, for instance, 
> iptables. Here we use it to report iptable logs per 
> contianer.
> 
> Then default printk targeted at the init_syslog_ns will 
> continue to print out most kernel log to host.
> 
> One task in a new syslog ns could affect only current 
> container through "dmesg", "dmesg -c" and /dev/kmsg 
> actions. The read/write interface such as /dev/kmsg, 
> /pro/kmsg and syslog syscall continue to be useful for 
> container users.
> 
> This patchset is based on linus' linux tree.

Changelog details between V2 and V1 is seriously needed, the inline description
is not easy reading for other guys.

> 
> Rui Xiang (9):
>   syslog_ns: add syslog_namespace and put/get_syslog_ns
>   syslog_ns: add syslog_ns into user_namespace
>   syslog_ns: add init syslog_ns for global syslog
>   syslog_ns: make syslog handling per namespace
>   syslog_ns: make permisiion check per user namespace
>   syslog_ns: use init syslog_ns for console action
>   syslog_ns: implement function for creating syslog ns
>   syslog_ns: implement ns_printk for specific syslog_ns
>   netfilter: use ns_printk in iptable context
> 
>  fs/proc/kmsg.c                 |  17 +-
>  include/linux/printk.h         |   5 +-
>  include/linux/syslog.h         |  79 ++++-
>  include/linux/user_namespace.h |   2 +
>  include/net/netfilter/xt_log.h |   6 +-
>  kernel/printk.c                | 642 ++++++++++++++++++++++++-----------------
>  kernel/sysctl.c                |   3 +-
>  kernel/user.c                  |   3 +
>  kernel/user_namespace.c        |   4 +
>  net/netfilter/xt_LOG.c         |   4 +-
>  10 files changed, 493 insertions(+), 272 deletions(-)
>