Signed-off-by: NFelix Jia <felix.jia@alliedtelesis.co.nz>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

vti6 interface is registered before the rtnl_link_ops block
is attached. As a result the resulting RTM_NEWLINK is missing
IFLA_INFO_KIND. Re-order attachment of rtnl_link_ops block to fix.
Signed-off-by: NDave Forster <dforster@brocade.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Make struct pernet_operations::id unsigned.

There are 2 reasons to do so:

1)
This field is really an index into an zero based array and
thus is unsigned entity. Using negative value is out-of-bound
access by definition.

2)
On x86_64 unsigned 32-bit data which are mixed with pointers
via array indexing or offsets added or subtracted to pointers
are preffered to signed 32-bit data.

"int" being used as an array index needs to be sign-extended
to 64-bit before being used.

	void f(long *p, int i)
	{
		g(p[i]);
	}

  roughly translates to

	movsx	rsi, esi
	mov	rdi, [rsi+...]
	call 	g

MOVSX is 3 byte instruction which isn't necessary if the variable is
unsigned because x86_64 is zero extending by default.

Now, there is net_generic() function which, you guessed it right, uses
"int" as an array index:

	static inline void *net_generic(const struct net *net, int id)
	{
		...
		ptr = ng->ptr[id - 1];
		...
	}

And this function is used a lot, so those sign extensions add up.

Patch snipes ~1730 bytes on allyesconfig kernel (without all junk
messing with code generation):

	add/remove: 0/0 grow/shrink: 70/598 up/down: 396/-2126 (-1730)

Unfortunately some functions actually grow bigger.
This is a semmingly random artefact of code generation with register
allocator being used differently. gcc decides that some variable
needs to live in new r8+ registers and every access now requires REX
prefix. Or it is shifted into r12, so [r12+0] addressing mode has to be
used which is longer than [r8]

However, overall balance is in negative direction:

	add/remove: 0/0 grow/shrink: 70/598 up/down: 396/-2126 (-1730)
	function                                     old     new   delta
	nfsd4_lock                                  3886    3959     +73
	tipc_link_build_proto_msg                   1096    1140     +44
	mac80211_hwsim_new_radio                    2776    2808     +32
	tipc_mon_rcv                                1032    1058     +26
	svcauth_gss_legacy_init                     1413    1429     +16
	tipc_bcbase_select_primary                   379     392     +13
	nfsd4_exchange_id                           1247    1260     +13
	nfsd4_setclientid_confirm                    782     793     +11
		...
	put_client_renew_locked                      494     480     -14
	ip_set_sockfn_get                            730     716     -14
	geneve_sock_add                              829     813     -16
	nfsd4_sequence_done                          721     703     -18
	nlmclnt_lookup_host                          708     686     -22
	nfsd4_lockt                                 1085    1063     -22
	nfs_get_client                              1077    1050     -27
	tcf_bpf_init                                1106    1076     -30
	nfsd4_encode_fattr                          5997    5930     -67
	Total: Before=154856051, After=154854321, chg -0.00%
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

- Use the UID in routing lookups made by protocol connect() and
  sendmsg() functions.
- Make sure that routing lookups triggered by incoming packets
  (e.g., Path MTU discovery) take the UID of the socket into
  account.
- For packets not associated with a userspace socket, (e.g., ping
  replies) use UID 0 inside the user namespace corresponding to
  the network namespace the socket belongs to. This allows
  all namespaces to apply routing and iptables rules to
  kernel-originated traffic in that namespaces by matching UID 0.
  This is better than using the UID of the kernel socket that is
  sending the traffic, because the UID of kernel sockets created
  at namespace creation time (e.g., the per-processor ICMP and
  TCP sockets) is the UID of the user that created the socket,
  which might not be mapped in the namespace.

Tested: compiles allnoconfig, allyesconfig, allmodconfig
Tested: https://android-review.googlesource.com/253302Signed-off-by: NLorenzo Colitti <lorenzo@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

ipv4/ip_tunnel:
- min_mtu = 68, max_mtu = 0xFFF8 - dev->hard_header_len - t_hlen
- preserve all ndo_change_mtu checks for now to prevent regressions

ipv6/ip6_tunnel:
- min_mtu = 68, max_mtu = 0xFFF8 - dev->hard_header_len
- preserve all ndo_change_mtu checks for now to prevent regressions

ipv6/ip6_vti:
- min_mtu = 1280, max_mtu = 65535
- remove redundant vti6_change_mtu

ipv6/sit:
- min_mtu = 1280, max_mtu = 0xFFF8 - t_hlen
- remove redundant ipip6_tunnel_change_mtu

CC: netdev@vger.kernel.org
CC: "David S. Miller" <davem@davemloft.net>
CC: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
CC: James Morris <jmorris@namei.org>
CC: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
CC: Patrick McHardy <kaber@trash.net>
Signed-off-by: NJarod Wilson <jarod@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This is the same fix than commit a5d0dc81 ("vti: flush x-netns xfrm
cache when vti interface is removed")

This patch fixes a refcnt problem when a x-netns vti6 interface is removed:
unregister_netdevice: waiting for vti6_test to become free. Usage count = 1

Here is a script to reproduce the problem:

ip link set dev ntfp2 up
ip addr add dev ntfp2 2001::1/64
ip link add vti6_test type vti6 local 2001::1 remote 2001::2 key 1
ip netns add secure
ip link set vti6_test netns secure
ip netns exec secure ip link set vti6_test up
ip netns exec secure ip link s lo up
ip netns exec secure ip addr add dev vti6_test 2003::1/64
ip -6 xfrm policy add dir out tmpl src 2001::1 dst 2001::2 proto esp \
	   mode tunnel mark 1
ip -6 xfrm policy add dir in tmpl src 2001::2 dst 2001::1 proto esp \
	   mode tunnel mark 1
ip xfrm state add src 2001::1 dst 2001::2 proto esp spi 1 mode tunnel \
	   enc des3_ede 0x112233445566778811223344556677881122334455667788 mark 1
ip xfrm state add src 2001::2 dst 2001::1 proto esp spi 1 mode tunnel \
	   enc des3_ede 0x112233445566778811223344556677881122334455667788 mark 1
ip netns exec secure  ping6 -c 4 2003::2
ip netns del secure

CC: Lance Richardson <lrichard@redhat.com>
Signed-off-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: NLance Richardson <lrichard@redhat.com>
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

Since commit 1625f452, vti6 is broken, all input packets are dropped
(LINUX_MIB_XFRMINNOSTATES is incremented).

XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6 is set by vti6_rcv() before calling
xfrm6_rcv()/xfrm6_rcv_spi(), thus we cannot set to NULL that value in
xfrm6_rcv_spi().

A new function xfrm6_rcv_tnl() that enables to pass a value to
xfrm6_rcv_spi() is added, so that xfrm6_rcv() is not touched (this function
is used in several handlers).

CC: Alexey Kodanev <alexey.kodanev@oracle.com>
Fixes: 1625f452 ("net/xfrm_input: fix possible NULL deref of tunnel.ip6->parms.i_key")
Signed-off-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

In case of inter address family tunneling (IPv6 over vti4 or IPv4 over
vti6), the inbound policy checks in vti_rcv_cb() and vti6_rcv_cb() are
using the wrong address family. As a result, all inbound inter address
family traffic is dropped.

Use the xfrm_ip2inner_mode() helper, as done in xfrm_input() (i.e., also
increment LINUX_MIB_XFRMINSTATEMODEERROR in case of error), to select the
inner_mode that contains the right address family for the inbound policy
checks.
Signed-off-by: NThomas Zeitlhofer <thomas.zeitlhofer+lkml@ze-it.at>
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

This is a preparatory patch for converting qdisc linked list into a
hashtable. As we'll need to include hashtable.h in netdevice.h, we first
have to make sure that this will not introduce symbol conflicts for any of
the netdevice.h users.
Reviewed-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This also fix a potential race into the existing tunnel code, which
could lead to the wrong dst to be permanenty cached:

CPU1:					CPU2:
  <xmit on ip6_tunnel>
  <cache lookup fails>
  dst = ip6_route_output(...)
					<tunnel params are changed via nl>
					dst_cache_reset() // no effect,
							// the cache is empty
  dst_cache_set() // the wrong dst
	// is permanenty stored
	// into the cache

With the new dst implementation the above race is not possible
since the first cache lookup after dst_cache_reset will fail due
to the timestamp check
Signed-off-by: NPaolo Abeni <pabeni@redhat.com>
Suggested-and-acked-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Replace dst_output_okfn with dst_output
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add a sock paramter to dst_output making dst_output_sk superfluous.
Add a skb->sk parameter to all of the callers of dst_output
Have the callers of dst_output_sk call dst_output.
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We currently rely on the PMTU discovery of xfrm.
However if a packet is localy sent, the PMTU mechanism
of xfrm tries to to local socket notification what
might not work for applications like ping that don't
check for this. So add pmtu handling to vti6_xmit to
report MTU changes immediately.
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: NAlexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The vti6_rcv_cb and vti_rcv_cb calls were leaving the skb->mark modified
after completing the function.  This resulted in the original skb->mark
value being lost.  Since we only need skb->mark to be set for
xfrm_policy_check we can pull the assignment into the rcv_cb calls and then
just restore the original mark after xfrm_policy_check has been completed.
Signed-off-by: NAlexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

Instead of modifying skb->mark we can simply modify the flowi_mark that is
generated as a result of the xfrm_decode_session.  By doing this we don't
need to actually touch the skb->mark and it can be preserved as it passes
out through the tunnel.
Signed-off-by: NAlexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

When the kernel deleted a vti6 interface, this interface was not removed from
the tunnels list. Thus, when the ip6_vti module was removed, this old interface
was found and the kernel tried to delete it again. This was leading to a kernel
panic.

Fixes: 61220ab3 ("vti6: Enable namespace changing")
Signed-off-by: NYao Xiwei <xiwei.yao@6wind.com>
Signed-off-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

Don't use dev->iflink anymore.

CC: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Those are counterparts to nla_put_in_addr and nla_put_in6_addr.
Signed-off-by: NJiri Benc <jbenc@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

IP addresses are often stored in netlink attributes. Add generic functions
to do that.

For nla_put_in_addr, it would be nicer to pass struct in_addr but this is
not used universally throughout the kernel, in way too many places __be32 is
used to store IPv4 address.
Signed-off-by: NJiri Benc <jbenc@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The ipv6 code uses a mixture of coding styles. In some instances check for NULL
pointer is done as x != NULL and sometimes as x. x is preferred according to
checkpatch and this patch makes the code consistent by adopting the latter
form.

No changes detected by objdiff.
Signed-off-by: NIan Morris <ipm@chirality.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The ipv6 code uses a mixture of coding styles. In some instances check for NULL
pointer is done as x == NULL and sometimes as !x. !x is preferred according to
checkpatch and this patch makes the code consistent by adopting the latter
form.

No changes detected by objdiff.
Signed-off-by: NIan Morris <ipm@chirality.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Implement rtnl_link_ops->get_link_net() callback so that IFLA_LINK_NETNSID is
added to rtnetlink messages.
Signed-off-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Now the vti_link_ops do not point the .dellink, for fb tunnel device
(ip_vti0), the net_device will be removed as the default .dellink is
unregister_netdevice_queue,but the tunnel still in the tunnel list,
then if we add a new vti tunnel, in ip_tunnel_find():

        hlist_for_each_entry_rcu(t, head, hash_node) {
                if (local == t->parms.iph.saddr &&
                    remote == t->parms.iph.daddr &&
                    link == t->parms.link &&
==>                 type == t->dev->type &&
                    ip_tunnel_key_match(&t->parms, flags, key))
                        break;
        }

the panic will happen, cause dev of ip_tunnel *t is null:
[ 3835.072977] IP: [<ffffffffa04103fd>] ip_tunnel_find+0x9d/0xc0 [ip_tunnel]
[ 3835.073008] PGD b2c21067 PUD b7277067 PMD 0
[ 3835.073008] Oops: 0000 [#1] SMP
.....
[ 3835.073008] Stack:
[ 3835.073008]  ffff8800b72d77f0 ffffffffa0411924 ffff8800bb956000 ffff8800b72d78e0
[ 3835.073008]  ffff8800b72d78a0 0000000000000000 ffffffffa040d100 ffff8800b72d7858
[ 3835.073008]  ffffffffa040b2e3 0000000000000000 0000000000000000 0000000000000000
[ 3835.073008] Call Trace:
[ 3835.073008]  [<ffffffffa0411924>] ip_tunnel_newlink+0x64/0x160 [ip_tunnel]
[ 3835.073008]  [<ffffffffa040b2e3>] vti_newlink+0x43/0x70 [ip_vti]
[ 3835.073008]  [<ffffffff8150d4da>] rtnl_newlink+0x4fa/0x5f0
[ 3835.073008]  [<ffffffff812f68bb>] ? nla_strlcpy+0x5b/0x70
[ 3835.073008]  [<ffffffff81508fb0>] ? rtnl_link_ops_get+0x40/0x60
[ 3835.073008]  [<ffffffff8150d11f>] ? rtnl_newlink+0x13f/0x5f0
[ 3835.073008]  [<ffffffff81509cf4>] rtnetlink_rcv_msg+0xa4/0x270
[ 3835.073008]  [<ffffffff8126adf5>] ? sock_has_perm+0x75/0x90
[ 3835.073008]  [<ffffffff81509c50>] ? rtnetlink_rcv+0x30/0x30
[ 3835.073008]  [<ffffffff81529e39>] netlink_rcv_skb+0xa9/0xc0
[ 3835.073008]  [<ffffffff81509c48>] rtnetlink_rcv+0x28/0x30
....

modprobe ip_vti
ip link del ip_vti0 type vti
ip link add ip_vti0 type vti
rmmod ip_vti

do that one or more times, kernel will panic.

fix it by assigning ip_tunnel_dellink to vti_link_ops' dellink, in
which we skip the unregister of fb tunnel device. do the same on ip6_vti.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NCong Wang <cwang@twopensource.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This change has no functional impact and simply addresses some coding
style issues detected by checkpatch. Specifically this change
adjusts "if" statements which also include the assignment of a
variable.

No changes to the resultant object files result as determined by objdiff.
Signed-off-by: NIan Morris <ipm@chirality.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently we can't lookup tunnels with wildcard endpoints.
This patch adds a method to lookup these tunnels in the
receive path.
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

Currently we need the IP6_TNL_F_CAP_XMIT capabiltiy to transmit
packets through an ipv6 tunnel. This capability is set when the
tunnel gets configured, based on the tunnel endpoint addresses.

On tunnels with wildcard tunnel endpoints, we need to do the
capabiltiy checking on a per packet basis like it is done in
the receive path.

This patch extends ip6_tnl_xmit_ctl() to take local and remote
addresses as parameters to allow for per packet capabiltiy
checking.
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

vti6_dev_init() sets the dev->iflink via a call to
vti6_link_config(). After that, register_netdevice()
sets dev->iflink = -1. So we loose the iflink configuration
for vti6 tunnels. Fix this by using vti6_dev_init() as the
ndo_init function. Then vti6_dev_init() is called after
dev->iflink is set to -1 from register_netdevice().
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Testing xmit_more support with netperf and connected UDP sockets,
I found strange dst refcount false sharing.

Current handling of IFF_XMIT_DST_RELEASE is not optimal.

Dropping dst in validate_xmit_skb() is certainly too late in case
packet was queued by cpu X but dequeued by cpu Y

The logical point to take care of drop/force is in __dev_queue_xmit()
before even taking qdisc lock.

As Julian Anastasov pointed out, need for skb_dst() might come from some
packet schedulers or classifiers.

This patch adds new helper to cleanly express needs of various drivers
or qdiscs/classifiers.

Drivers that need skb_dst() in their ndo_start_xmit() should call
following helper in their setup instead of the prior :

	dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
->
	netif_keep_dst(dev);

Instead of using a single bit, we use two bits, one being
eventually rebuilt in bonding/team drivers.

The other one, is permanent and blocks IFF_XMIT_DST_RELEASE being
rebuilt in bonding/team. Eventually, we could add something
smarter later.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Julian Anastasov <ja@ssi.bg>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

vti6_locate() should not return an existing tunnel if
create is true. Otherwise it is possible to add the same
tunnel multiple times without getting an error.

So return NULL if the tunnel that should be created already
exists.
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Extend alloc_netdev{,_mq{,s}}() to take name_assign_type as argument, and convert
all users to pass NET_NAME_UNKNOWN.

Coccinelle patch:

@@
expression sizeof_priv, name, setup, txqs, rxqs, count;
@@

(
-alloc_netdev_mqs(sizeof_priv, name, setup, txqs, rxqs)
+alloc_netdev_mqs(sizeof_priv, name, NET_NAME_UNKNOWN, setup, txqs, rxqs)
|
-alloc_netdev_mq(sizeof_priv, name, setup, count)
+alloc_netdev_mq(sizeof_priv, name, NET_NAME_UNKNOWN, setup, count)
|
-alloc_netdev(sizeof_priv, name, setup)
+alloc_netdev(sizeof_priv, name, NET_NAME_UNKNOWN, setup)
)

v9: move comments here from the wrong commit
Signed-off-by: NTom Gundersen <teg@jklm.no>
Reviewed-by: NDavid Herrmann <dh.herrmann@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The error handling in the module init and exit functions can be
shortened to safe us some code.

1/ Remove the code duplications in the init function, jump straight to
the existing cleanup code by adding some labels. Also give the error
message some more value by telling the reason why loading the module has
failed.

2/ Remove the error handling in the exit function as the only legitimate
reason xfrm6_protocol_deregister() might fail is inet6_del_protocol()
returning -1. That, in turn, means some other protocol handler had been
registered for this very protocol in the meantime. But that essentially
means we haven't been handling that protocol any more, anyway. What it
definitely means not is that we "can't deregister protocol". Therefore
just get rid of that bogus warning. It's plain wrong.
Signed-off-by: NMathias Krause <minipli@googlemail.com>
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

Netdev_priv is an accessor function, and has no purpose if its result is
not used.

A simplified version of the semantic match that fixes this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@@ local idexpression x; @@
-x = netdev_priv(...);
... when != x
// </smpl>
Signed-off-by: NJulia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We need to use the mark we get from the tunnels o_key to
lookup the right vti state in the error handlers. This patch
ensures that.

Fixes: df3893c1 ("vti: Update the ipv4 side to use it's own receive hook.")
Fixes: fa9ad96d ("vti6: Update the ipv6 side to use its own receive hook.")
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

If we fail to register one of the xfrm protocol handlers we will
unregister the pernet ops twice on the error exit path. This will
probably lead to a kernel panic as the double deregistration
leads to a double kfree().

Fix this by removing one of the calls to do it only once.

Fixes: fa9ad96d ("vti6: Update the ipv6 side to use its own...")
Signed-off-by: NMathias Krause <minipli@googlemail.com>
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

vti6 is now fully namespace aware, so allow namespace changing
for vti devices.
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

The tunnel endpoints of the xfrm_state we got from the xfrm_lookup
must match the tunnel endpoints of the vti interface. This patch
ensures this matching.
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

With this patch we can tunnel ipv4 traffic via a vti6
interface. A vti6 interface can now have an ipv4 address
and ipv4 traffic can be routed via a vti6 interface.
The resulting traffic is xfrm transformed and tunneled
through ipv6 if matching IPsec policies and states are
present.
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

With this patch, vti6 uses the IPsec protocol multiplexer to
register its own receive side hooks for ESP, AH and IPCOMP.

Vti6 now does the following on receive side:

1. Do an input policy check for the IPsec packet we received.
   This is required because this packet could be already
   prosecces by IPsec, so an inbuond policy check is needed.

2. Mark the packet with the i_key. The policy and the state
   must match this key now. Policy and state belong to the vti
   namespace and policy enforcement is done at the further layers.

3. Call the generic xfrm layer to do decryption and decapsulation.

4. Wait for a callback from the xfrm layer to properly clean the
   skb to not leak informations on namespace transitions and
    update the device statistics.

On transmit side:

1. Mark the packet with the o_key. The policy and the state
   must match this key now.

2. Do a xfrm_lookup on the original packet with the mark applied.

3. Check if we got an IPsec route.

4. Clean the skb to not leak informations on namespace
   transitions.

5. Attach the dst_enty we got from the xfrm_lookup to the skb.

6. Call dst_output to do the IPsec processing.

7. Do the device statistics.
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

Unlike ip6_tunnel, vti6 does not use the the tunnel
endpoint addresses to do route and xfrm lookups.
So no need to cache the flow informations. It also
does not make sense to calculate the mtu based on
such flow informations, so remove this too.
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

Unlike ip6_tunnel, vti6 can lookup multiple different dst entries,
dependent of the configured xfrm states. Therefore it does not make
sense to cache a dst_entry.
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>