7 Mar
2016
7 Mar
'16
2:31 p.m.
On Fri, Mar 04, 2016 at 01:35:01PM +0100, Sven Eckelmann wrote:
On Tuesday 01 March 2016 22:19:07 Andrew Lunn wrote:
Hi Sven
How are you determining this? It compiled fine for me, which is my
usual test.
batman-adv tries to prevent the user from placing
a batX soft
interface into another batman mesh as a hard interface. It does this
by walking up the devices list of parents and ensures they are all
none batX interfaces. iflink can point to an interface in a different
namespace, so also retrieve the parents name space when finding the
parent and use it when doing the comparison.
Signed-off-by: Andrew Lunn <andrew(a)lunn.ch>
Acked-by: Antonio Quartulli <a(a)untable.cc>
---
net/batman-adv/hard-interface.c | 31 ++++++++++++++++++++++++-------
1 file changed, 24 insertions(+), 7 deletions(-)
Include missing in net/batman-adv/hard-interface.c
#include <net/rtnetlink.h>
Does anyone (not only Andrew) have a proposal regarding the compat code?
Patch 1+2 should be unproblematic (maybe these can already be applied?).
I've not much history with netns. One thing which might be interesting
it know, is when did it become mature enough to the usable? Maybe for
kernels older than v4.0, deny that netns exists, and find a way for
functions like get_link_net() to return the default net.
compat.h could contain
#if (LINUX_VERSION_CODE < KERNEL_VERSION(4, 0, 0))
#if IS_ENABLED(CONFIG_NET_NS)
#error Network Namespaces not support with this vintage of kernel. Please disable
#endif
#endif
You then know everything is going to be in the default namespace for
these old kernels.
This patch here is the first problematic one because
it uses get_link_net
which was first introduced in v4.0 with d37512a277df ("rtnl: add link netns
id to interface messages"). I personally see some function substractions
coming at us. But then it would be better to have this code in a smaller
function to make "patching" easier (but I don't have a complete solution
right now):
dev_parent_net = default_net;
if (dev->rtnl_link_ops && dev->rtnl_link_ops->get_link_net)
dev_parent_net = dev->rtnl_link_ops->get_link_net(dev);
Horrible, and i have no idea if it actually works, but how about
#if (LINUX_VERSION_CODE < KERNEL_VERSION(4, 0, 0))
#define dev->rtnl_link_ops->get_link_net true
#define dev->rtnl_link_ops->get_link_net(dev) init_net
#endif
so we get the default namespace.
The next problematic part in regards of compat stuff
is the patch 4.
linux/ns_common.h is missing (can be added without a problem in
compat-includes). More problematic is the net::ns substruct (to be more
precise the net::ns.inum) which was first introduced in 3.19 with
435d5f4bb2cc ("common object embedded into various struct ....ns") and
was previously called net::proc_inum (3.8-3.18) and did not exist
before v3.8 98f842e675f9 ("proc: Usable inode numbers for the
namespace file descriptors.").
How about something along the lines of
#if (LINUX_VERSION_CODE < KERNEL_VERSION(4, 0, 0))
#define init_net.ns.inum 42
#define net->ns.inum 42
#endif
Andrew