[PATCH 0/9] Add namespace support for syslog v2
rui.xiang at huawei.com
Tue Jul 30 02:11:48 UTC 2013
Thanks for your attention.
On 2013/7/30 2:58, Eric W. Biederman wrote:
> Rui Xiang <rui.xiang at huawei.com> writes:
>> This patchset introduces a system log namespace.
> The largest outstanding question is not answered. Can't we just fix
> iptables to log somehwere better than dmesg, and would that not entirely
> remove the need for this work?
I don't think there is any question. In this patchset, patch(1-8) implement
a mechanism for syslog_ns. And iptables is an actual scene to use ns. So we
can treat patch9 as a instance for syslog_ns.
Sorry for my negligence, I will add some detailed logs in next version.
> That question needs to be answered before we proceed down this path.
>> 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
>> 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.
>> 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(-)
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