On Wed, 2010-07-07 at 12:56 -0400, J. Bruce Fields wrote: > On Wed, Jul 07, 2010 at 10:31:21AM -0400, David P. Quigley wrote: > > This patch adds two entries into the fs/KConfig file. The first entry > > NFS_V4_SECURITY_LABEL enables security label support for the NFSv4 client while > > the second entry NFSD_V4_SECURITY_LABEL enables security labeling support on > > the server side. > > Will there also be some way to turn these on and off at run-time (maybe > for particular exports or filesystems?) > > And if so, will there be any reason not to have this on all the time? I > don't think we'll want a config option for every future possible NFSv4.x > feature. The way the code currently works is if you want security labeling on an export you need to put the sec_label option on your export line (we have a modified nfs-utils to accept that option). This will set the particular capability flag for security labeling support on the server. After that it works like any other capability. I don't think there is a need to turn it on/off without reexporting the file system especially since I'm not sure if there is a way to regrab the server capabilities after the initial mount. I don't see why we couldn't not have this on at all times from a kconfig perspective. I can make sure that the code is prepared to always be there and handle when there is no need for it to be used. A little bit of a background on how SELinux will handle this (other LSMs are welcome to do what they like). If you want to turn security labeling on/off on a per export basis we have the sec_label export option for that. If you have a file system that is exported with sec_label and you don't want to use security labels from the server SELinux provides a capability called context mounts. It allows us to set the label for every file on that mount point regardless of whether the file system provides other labeling capabilities. So if we have a server exporting /www with security labels and we don't want to trust it I would use a mount command like the one below to set the security label for the entire mount mount -t nfs4 -o context="system_u:object_r:httpd_sys_content_t:s0" localhost:/www /mnt/www Dave -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
