linux.git/net/ipv6/sit.c, branch v4.15

net: don't call update_pmtu unconditionally

2018-01-25T21:27:34+00:00

Some dst_ops (e.g. md_dst_ops)) doesn't set this handler. It may result to:
"BUG: unable to handle kernel NULL pointer dereference at           (null)"

Let's add a helper to check if update_pmtu is available before calling it.

Fixes: 52a589d51f10 ("geneve: update skb dst pmtu on tx path")
Fixes: a93bf0ff4490 ("vxlan: update skb dst pmtu on tx path")
CC: Roman Kapl 
CC: Xin Long 
Signed-off-by: Nicolas Dichtel 
Signed-off-by: David S. Miller

sit: update frag_off info

2017-11-30T15:25:41+00:00

After parsing the sit netlink change info, we forget to update frag_off in
ipip6_tunnel_update(). Fix it by assigning frag_off with new value.

Reported-by: Jianlin Shi 
Signed-off-by: Hangbin Liu 
Acked-by: Nicolas Dichtel 
Signed-off-by: David S. Miller

net: sit: Update lookup to handle links set to L3 slave

2017-11-01T03:35:17+00:00

Using SIT tunnels with VRFs works fine if the underlay device is in a
VRF and the link parameter is set to the VRF device. e.g.,

    ip tunnel add jtun mode sit remote  local  dev myvrf

Update the device check to allow the link to be the enslaved device as
well. e.g.,

    ip tunnel add jtun mode sit remote  local  dev eth4

where eth4 is enslaved to myvrf.

Reported-by: Jeff Barnhill <0xeffeff@gmail.com>
Signed-off-by: David Ahern 
Signed-off-by: David S. Miller

ipv6: speedup ipv6 tunnels dismantle

2017-09-19T23:32:23+00:00

Implement exit_batch() method to dismantle more devices
per round.

(rtnl_lock() ...
 unregister_netdevice_many() ...
 rtnl_unlock())

Tested:
$ cat add_del_unshare.sh
for i in `seq 1 40`
do
 (for j in `seq 1 100` ; do unshare -n /bin/true >/dev/null ; done) &
done
wait ; grep net_namespace /proc/slabinfo

Before patch :
$ time ./add_del_unshare.sh
net_namespace        110    267   5504    1    2 : tunables    8    4    0 : slabdata    110    267      0

real    3m25.292s
user    0m0.644s
sys     0m40.153s

After patch:

$ time ./add_del_unshare.sh
net_namespace        126    282   5504    1    2 : tunables    8    4    0 : slabdata    126    282      0

real	1m38.965s
user	0m0.688s
sys	0m37.017s

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2017-06-30T16:43:08+00:00

A set of overlapping changes in macvlan and the rocker
driver, nothing serious.

Signed-off-by: David S. Miller

net: add netlink_ext_ack argument to rtnl_link_ops.validate

2017-06-27T03:13:22+00:00

Add support for extended error reporting.

Signed-off-by: Matthias Schiffer 
Acked-by: David Ahern 
Signed-off-by: David S. Miller

net: add netlink_ext_ack argument to rtnl_link_ops.changelink

2017-06-27T03:13:22+00:00

Add support for extended error reporting.

Signed-off-by: Matthias Schiffer 
Acked-by: David Ahern 
Signed-off-by: David S. Miller

net: add netlink_ext_ack argument to rtnl_link_ops.newlink

2017-06-27T03:13:21+00:00

Add support for extended error reporting.

Signed-off-by: Matthias Schiffer 
Acked-by: David Ahern 
Signed-off-by: David S. Miller

sit: use __GFP_NOWARN for user controlled allocation

2017-06-23T18:08:40+00:00

The memory allocation size is controlled by user-space,
if it is too large just fail silently and return NULL,
not to mention there is a fallback allocation later.

Reported-by: Andrey Konovalov 
Signed-off-by: Cong Wang 
Tested-by: Andrey Konovalov 
Signed-off-by: David S. Miller

net: Fix inconsistent teardown and release of private netdev state.

2017-06-07T19:53:24+00:00

Network devices can allocate reasources and private memory using
netdev_ops->ndo_init().  However, the release of these resources
can occur in one of two different places.

Either netdev_ops->ndo_uninit() or netdev->destructor().

The decision of which operation frees the resources depends upon
whether it is necessary for all netdev refs to be released before it
is safe to perform the freeing.

netdev_ops->ndo_uninit() presumably can occur right after the
NETDEV_UNREGISTER notifier completes and the unicast and multicast
address lists are flushed.

netdev->destructor(), on the other hand, does not run until the
netdev references all go away.

Further complicating the situation is that netdev->destructor()
almost universally does also a free_netdev().

This creates a problem for the logic in register_netdevice().
Because all callers of register_netdevice() manage the freeing
of the netdev, and invoke free_netdev(dev) if register_netdevice()
fails.

If netdev_ops->ndo_init() succeeds, but something else fails inside
of register_netdevice(), it does call ndo_ops->ndo_uninit().  But
it is not able to invoke netdev->destructor().

This is because netdev->destructor() will do a free_netdev() and
then the caller of register_netdevice() will do the same.

However, this means that the resources that would normally be released
by netdev->destructor() will not be.

Over the years drivers have added local hacks to deal with this, by
invoking their destructor parts by hand when register_netdevice()
fails.

Many drivers do not try to deal with this, and instead we have leaks.

Let's close this hole by formalizing the distinction between what
private things need to be freed up by netdev->destructor() and whether
the driver needs unregister_netdevice() to perform the free_netdev().

netdev->priv_destructor() performs all actions to free up the private
resources that used to be freed by netdev->destructor(), except for
free_netdev().

netdev->needs_free_netdev is a boolean that indicates whether
free_netdev() should be done at the end of unregister_netdevice().

Now, register_netdevice() can sanely release all resources after
ndo_ops->ndo_init() succeeds, by invoking both ndo_ops->ndo_uninit()
and netdev->priv_destructor().

And at the end of unregister_netdevice(), we invoke
netdev->priv_destructor() and optionally call free_netdev().

Signed-off-by: David S. Miller