When CONFIG_PROC_FS is not set and CONFIG_PPPOL2TP is set,
we have the following warning in build:
  drivers/net/pppol2tp.c: In function 'pppol2tp_init':
  drivers/net/pppol2tp.c:2472: warning: label
'out_unregister_pppox_proto' defined but not used

This patches fixes this warning by adding appropriate #ifdef.
Signed-off-by: NRami Rosen <ramirose@gmail.com>
Acked-by: NJames Chapman <jchapman@katalix.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Changes made on 18-sep to fix skb handling in the pppol2tp driver
broke the transmit and receive paths. Users are only running into this
now because distros are now using 2.6.23 and I must have messed up
when I tested the change.

For receive, we now do our own calculation of how much to pull from
the skb (variable length L2TP header) rather than using
skb_transport_offset(). Also, if the skb isn't a data packet, it must
be passed back to UDP with skb->data pointing to the UDP header.

For transmit, make sure skb->sk is set up because ip_queue_xmit()
needs it.
Signed-off-by: NJames Chapman <jchapman@katalix.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Finally, the zero_it argument can be completely removed from
the callers and from the function prototype.

Besides, fix the checkpatch.pl warnings about using the
assignments inside if-s.

This patch is rather big, and it is a part of the previous one.
I splitted it wishing to make the patches more readable. Hope 
this particular split helped.
Signed-off-by: NPavel Emelyanov <xemul@openvz.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch passes in the namespace a new socket should be created in
and has the socket code do the appropriate reference counting.  By
virtue of this all socket create methods are touched.  In addition
the socket create methods are modified so that they will fail if
you attempt to create a socket in a non-default network namespace.

Failing if we attempt to create a socket outside of the default
network namespace ensures that as we incrementally make the network stack
network namespace aware we will not export functionality that someone
has not audited and made certain is network namespace safe.
Allowing us to partially enable network namespaces before all of the
exotic protocols are supported.

Any protocol layers I have missed will fail to compile because I now
pass an extra parameter into the socket creation code.

[ Integrated AF_IUCV build fixes from Andrew Morton... -DaveM ]
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch makes /proc/net per network namespace.  It modifies the global
variables proc_net and proc_net_stat to be per network namespace.
The proc_net file helpers are modified to take a network namespace argument,
and all of their callers are fixed to pass &init_net for that argument.
This ensures that all of the /proc/net files are only visible and
usable in the initial network namespace until the code behind them
has been updated to be handle multiple network namespaces.

Making /proc/net per namespace is necessary as at least some files
in /proc/net depend upon the set of network devices which is per
network namespace, and even more files in /proc/net have contents
that are relevant to a single network namespace.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch makes pppol2tp_xmit call skb_cow_head so that we don't modify
cloned skb data.  It also gets rid of skb2 we only need to preserve the
original skb for congestion notification, which is only applicable for
ppp_async and ppp_sync.

The other semantic change made here is the removal of socket accounting
for data tranmitted out of pppol2tp_xmit.  The original code leaked any
existing socket skb accounting.  We could fix this by dropping the
original skb owner.  However, this is undesirable as the packet has not
physically left the host yet.

In fact, all other tunnels in the kernel do not account skb's passing
through to their own socket.  In partciular, ESP over UDP does not do
so and it is the closest tunnel type to PPPoL2TP.  So this patch simply
removes the socket accounting in pppol2tp_xmit.  The accounting still
applies to control packets of course.

I've also added a reminder that the outgoing checksum here doesn't work.
I suppose existing deployments don't actually enable checksums.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The function pppol2tp_recv_core doesn't handle non-linear packets properly.
It also fails to check the remote offset field.

This patch fixes these problems.  It also removes an unnecessary check on
the UDP header which has already been performed by the UDP layer.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

With the addition of UDP-Lite we need to refine the socket check so
that only genuine UDP sockets are allowed through.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Address of auto variable is not a userland pointer.  A good thing, too,
since if pppol2tp_tunnel_getsockopt() would _really_ get a userland pointer
as argument, it would be an instant roothole...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Reset netfilter data and IP CB, fix dst_entry leak.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Don't use skb->len after passing it to ip_queue_xmit.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This driver handles only L2TP data frames; control frames are handled
by a userspace application. It implements L2TP using the PPPoX socket
family. There is a PPPoX socket for each L2TP session in an L2TP
tunnel.  PPP data within each session is passed through the kernel's
PPP subsystem via this driver. Kernel parameters of each socket can be
read or modified using ioctl() or [gs]etsockopt() calls.
Signed-off-by: NJames Chapman <jchapman@katalix.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>