From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guillaume Nault Date: Thu, 21 Apr 2016 16:22:48 +0000 Subject: [RFC PATCH v3 0/2] ppp: add rtnetlink support Message-Id: List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: netdev@vger.kernel.org Cc: linux-ppp@vger.kernel.org, David Miller , Paul Mackerras , Stephen Hemminger , walter harms PPP devices lack the ability to be customised at creation time. In particular they can't be created in a given netns or with a particular name. Moving or renaming the device after creation is possible, but creates undesirable transient effects on servers where PPP devices are constantly created and removed, as users connect and disconnect. Implementing rtnetlink support solves this problem. The rtnetlink handlers implemented in this series are minimal, and can only replace the PPPIOCNEWUNIT ioctl. The rest of PPP ioctls remains necessary for any other operation on channels and units. It is perfectly possible to mix PPP devices created by rtnl and by ioctl(PPPIOCNEWUNIT). Devices will behave in the same way. If necessary, rtnetlink support could be extended to provide some of the functionalities brought by ppp_net_ioctl() and ppp_ioctl(). This would let external programs, like "ip link", set or retrieve PPP device information. However, I haven't made my mind on the usefulness of this approach, so this isn't implemented in this series. This series doesn't try to invert lock ordering between ppp_mutex and rtnl_lock. mutex_trylock() is used instead, which greatly simplifies things. A user visible difference brought by this series is that old PPP interfaces (those created with ioctl(PPPIOCNEWUNIT)), can now be removed by "ip link del", just like new rtnl based PPP devices. Changes since v2: - Define ->rtnl_link_ops for ioctl based PPP devices, so they can handle rtnl messages just like rtnl based ones (suggested by Stephen Hemminger). - Move back to original lock ordering between ppp_mutex and rtnl_lock to simplify patch series. Handle lock inversion issue using mutex_trylock() (suggested by Stephen Hemminger). - Do file descriptor lookup directly in ppp_nl_newlink(), to simplify ppp_dev_configure(). Changes since v1: - Rebase on net-next. - Invert locking order wrt. ppp_mutex and rtnl_lock and protect file->private_data with ppp_mutex. Guillaume Nault (2): ppp: define reusable device creation functions ppp: add rtnetlink device creation support drivers/net/ppp/ppp_generic.c | 315 ++++++++++++++++++++++++++++++------------ include/uapi/linux/if_link.h | 8 ++ 2 files changed, 235 insertions(+), 88 deletions(-) -- 2.8.1