TCP listener refactoring, part 4 :
To speed up inet lookups, we moved IPv4 addresses from inet to struct
sock_common
Now is time to do the same for IPv6, because it permits us to have fast
lookups for all kind of sockets, including upcoming SYN_RECV.
Getting IPv6 addresses in TCP lookups currently requires two extra cache
lines, plus a dereference (and memory stall).
inet6_sk(sk) does the dereference of inet_sk(__sk)->pinet6
This patch is way bigger than its IPv4 counter part, because for IPv4,
we could add aliases (inet_daddr, inet_rcv_saddr), while on IPv6,
it's not doable easily.
inet6_sk(sk)->daddr becomes sk->sk_v6_daddr
inet6_sk(sk)->rcv_saddr becomes sk->sk_v6_rcv_saddr
And timewait socket also have tw->tw_v6_daddr & tw->tw_v6_rcv_saddr
at the same offset.
We get rid of INET6_TW_MATCH() as INET6_MATCH() is now the generic
macro.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
TCP listener refactoring, part 3 :
Our goal is to hash SYN_RECV sockets into main ehash for fast lookup,
and parallel SYN processing.
Current inet_ehash_bucket contains two chains, one for ESTABLISH (and
friend states) sockets, another for TIME_WAIT sockets only.
As the hash table is sized to get at most one socket per bucket, it
makes little sense to have separate twchain, as it makes the lookup
slightly more complicated, and doubles hash table memory usage.
If we make sure all socket types have the lookup keys at the same
offsets, we can use a generic and faster lookup. It turns out TIME_WAIT
and ESTABLISHED sockets already have common lookup fields for IPv4.
[ INET_TW_MATCH() is no longer needed ]
I'll provide a follow-up to factorize IPv6 lookup as well, to remove
INET6_TW_MATCH()
This way, SYN_RECV pseudo sockets will be supported the same.
A new sock_gen_put() helper is added, doing either a sock_put() or
inet_twsk_put() [ and will support SYN_RECV later ].
Note this helper should only be called in real slow path, when rcu
lookup found a socket that was moved to another identity (freed/reused
immediately), but could eventually be used in other contexts, like
sock_edemux()
Before patch :
dmesg | grep "TCP established"
TCP established hash table entries: 524288 (order: 11, 8388608 bytes)
After patch :
TCP established hash table entries: 524288 (order: 10, 4194304 bytes)
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Conflicts:
include/linux/netdevice.h
net/core/sock.c
Trivial merge issues.
Removal of "extern" for functions declaration in netdevice.h
at the same time "const" was added to an argument.
Two parallel line additions in net/core/sock.c
Signed-off-by: David S. Miller <davem@davemloft.net>
Ben Hutchings says:
====================
Some more fixes for EF10 support; hopefully the last lot:
1. Fixes for reading statistics, from Edward Cree and Jon Cooper.
2. Addition of ethtool statistics for packets dropped by the hardware
before they were associated with a specific function, from Edward Cree.
3. Only bind to functions that are in control of their associated port,
as the driver currently assumes this is the case.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Steinar reported FQ pacing was not working for UDP flows.
It looks like the initial sk->sk_pacing_rate value of 0 was
a wrong choice. We should init it to ~0U (unlimited)
Then, TCA_FQ_FLOW_DEFAULT_RATE should be removed because it makes
no real sense. The default rate is really unlimited, and we
need to avoid a zero divide.
Reported-by: Steinar H. Gunderson <sesse@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This reverts commit 612c337306.
As per Stephen Hemminger, the layout of the netlink attribute
is not implemented correctly so revert this for now.
Signed-off-by: David S. Miller <davem@davemloft.net>
Add the missing destroy_workqueue() before return from
qlcnic_probe() in the error handling case.
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch fix the error handling in moxart_mac_probe():
- return -ENOMEM in some memory alloc fail cases
- add missing free_netdev() in the error handling case
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch fixes the calculation of the nlmsg size, by adding the missing
nla_total_size().
Cc: Patrick McHardy <kaber@trash.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
TCA_FQ_INITIAL_QUANTUM should set q->initial_quantum
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Unlike ipv4, the struct member hlen holds the length of the GRE and ipv6
headers. This length is also counted in dev->hard_header_len.
Perhaps, it's more clean to modify the hlen to count only the GRE header
without ipv6 header as the variable name suggest, but the simple way to fix
this without regression risk is simply modify the calculation of the limit
in ip6gre_tunnel_change_mtu function.
Verified in kernel version v3.11.
Signed-off-by: Oussama Ghorbel <ou.ghorbel@gmail.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
We can get classid through cgroup_subsys_state,
this is directviewing and effective.
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since the tasks have been migrated to the cgroup,
there is no need to call task_netprioidx to get
task's cgroup id.
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The since the removal of the routing cache computing
fib_compute_spec_dst() does a fib_table lookup for each UDP multicast
packet received. This has introduced a performance regression for some
UDP workloads.
This change skips populating the packet info for sockets that do not have
IP_PKTINFO set.
Benchmark results from a netperf UDP_RR test:
Before 89789.68 transactions/s
After 90587.62 transactions/s
Benchmark results from a fio 1 byte UDP multicast pingpong test
(Multicast one way unicast response):
Before 12.63us RTT
After 12.48us RTT
Signed-off-by: Shawn Bohrer <sbohrer@rgmadvisors.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The removal of the routing cache introduced a performance regression for
some UDP workloads since a dst lookup must be done for each packet.
This change caches the dst per socket in a similar manner to what we do
for TCP by implementing early_demux.
For UDP multicast we can only cache the dst if there is only one
receiving socket on the host. Since caching only works when there is
one receiving socket we do the multicast socket lookup using RCU.
For UDP unicast we only demux sockets with an exact match in order to
not break forwarding setups. Additionally since the hash chains may be
long we only check the first socket to see if it is a match and not
waste extra time searching the whole chain when we might not find an
exact match.
Benchmark results from a netperf UDP_RR test:
Before 87961.22 transactions/s
After 89789.68 transactions/s
Benchmark results from a fio 1 byte UDP multicast pingpong test
(Multicast one way unicast response):
Before 12.97us RTT
After 12.63us RTT
Signed-off-by: Shawn Bohrer <sbohrer@rgmadvisors.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
UDP sockets can receive packets from multiple endpoints and thus may be
received on multiple receive queues. Since packets packets can arrive
on multiple receive queues we should not mark the napi_id for all
packets. This makes busy read/poll only work for connected UDP sockets.
This additionally enables busy read/poll for UDP multicast packets as
long as the socket is connected by moving the check into
__udp_queue_rcv_skb().
Signed-off-by: Shawn Bohrer <sbohrer@rgmadvisors.com>
Suggested-by: Eric Dumazet <edumazet@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
qdisc_tree_decrease_qlen() is called when some packets are dropped
on a qdisc, and we want to notify parents of qlen changes.
We also can increment parents qdisc qstats drop counters.
This permits more accurate drop counters up to root qdisc.
For example a graft operation typically resets a qdisc
(drops all packets) and call qdisc_tree_decrease_qlen()
Note that callers are responsible for their drop counters.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If a guest is destroyed without transitioning its frontend to CLOSED,
the domain becomes a zombie as netback was not grant unmapping the
shared rings.
When removing a VIF, transition the backend to CLOSED so the VIF is
disconnected if necessary (which will unmap the shared rings etc).
This fixes a regression introduced by
279f438e36 (xen-netback: Don't destroy
the netdev until the vif is shut down).
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Wei Liu <wei.liu2@citrix.com>
Cc: Paul Durrant <Paul.Durrant@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Reviewed-by: Paul Durrant <paul.durrant@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Amir Vadai says:
====================
net/mlx4_en: Fix pages never dma unmapped on rx
This patchset fixes a bug introduced by commit 51151a16 (mlx4: allow order-0
memory allocations in RX path). Where dma_unmap_page wasn't called.
Changes from V0:
- Added "Rename name of mlx4_en_rx_alloc members". Old names were confusing.
- Last frag in page calculation was wrong. Since all frags in page are of the
same size, need to add this frag_stride to end of frag offset, and not the
size of next frag in skb.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch fixes a bug introduced by commit 51151a16 (mlx4: allow
order-0 memory allocations in RX path).
dma_unmap_page never reached because condition to detect last fragment
in page is wrong. offset+frag_stride can't be greater than size, need to
make sure no additional frag will fit in page => compare offset +
frag_stride + next_frag_size instead.
next_frag_size is the same as the current one, since page is shared only
with frags of the same size.
CC: Eric Dumazet <edumazet@google.com>
Signed-off-by: Amir Vadai <amirv@mellanox.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add page prefix to page related members: @size and @offset into
@page_size and @page_offset
CC: Eric Dumazet <edumazet@google.com>
Signed-off-by: Amir Vadai <amirv@mellanox.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently, in TLB mode we change mac addresses only by memcpy-ing the to
net_device->dev_addr, without actually setting them via
dev_set_mac_address(). This permits us to receive all the traffic always on
one mac address.
However, in case the interface flips, some drivers might enforce the
mac filtering for its FW/HW based on current ->dev_addr, and thus we won't
be able to receive traffic on that interface, in case it will be selected
as active in TLB mode.
Fix it by setting the mac address forcefully on every new active slave that
we select in TLB mode.
CC: Jay Vosburgh <fubar@us.ibm.com>
CC: Andy Gospodarek <andy@greyhouse.net>
CC: Yuval Mintz <yuvalmin@broadcom.com>
Reported-by: Yuval Mintz <yuvalmin@broadcom.com>
Tested-by: Yuval Mintz <yuvalmin@broadcom.com>
Signed-off-by: Veaceslav Falico <vfalico@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch will fix RX packets errors when receiving big size
of data by set bit RNC = 1.
RNC - Receive Enable Control
0: Upon completion of reception of one frame, the E-DMAC writes
the receive status to the descriptor and clears the RR bit in
EDRRR to 0.
1: Upon completion of reception of one frame, the E-DMAC writes
(writes back) the receive status to the descriptor. In addition,
the E-DMAC reads the next descriptor and prepares for reception
of the next frame.
In addition, for get more stable when receiving packets, I set
maximum size for the transmit/receive FIFO and inserts padding
in receive data.
Signed-off-by: Nguyen Hong Ky <nh-ky@jinso.co.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/l2tp/l2tp_core.c: In function ‘l2tp_verify_udp_checksum’:
net/l2tp/l2tp_core.c:499:22: warning: unused variable ‘tunnel’ [-Wunused-variable]
Create a helper "l2tp_tunnel()" to facilitate this, and as a side
effect get rid of a bunch of unnecessary void pointer casts.
Signed-off-by: David S. Miller <davem@davemloft.net>
We play with a wait queue even if socket is
non blocking. This is an obvious waste.
Besides, it will prevent calling the non blocking
variant when current is not valid.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Alan Ott says:
====================
Fix race conditions in mrf24j40 interrupts
After testing with the betas of this patchset, it's been rebased and is
ready for inclusion.
David Hauweele noticed that the mrf24j40 would hang arbitrarily after some
period of heavy traffic. Two race conditions were discovered, and the
driver was changed to use threaded interrupts, since the enable/disable of
interrupts in the driver has recently been a lighning rod whenever issues
arise related to interrupts (costing engineering time), and since threaded
interrupts are the right way to do it.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
The mrf24j40 generates level interrupts. There are rare cases where it
appears that the interrupt line never gets de-asserted between interrupts,
causing interrupts to be lost, and causing a hung device from the driver's
perspective. Switching the driver to interpret these interrupts as
level-triggered fixes this issue.
Signed-off-by: Alan Ott <alan@signal11.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
Eliminate all the workqueue and interrupt enable/disable.
Signed-off-by: Alan Ott <alan@signal11.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
This avoids a race condition where complete(tx_complete) could be called
before tx_complete is initialized.
Signed-off-by: Alan Ott <alan@signal11.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
Alan Ott says:
====================
Alexander Aring suggested that devices desired to be linked to 6lowpan
be checked for actually being of type IEEE802154, since IEEE802154 devices
are all that are supported by 6lowpan at present.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
When a lowpan link to a wpan device is created, set the hardware address
of the lowpan link to that of the wpan device.
Signed-off-by: Alan Ott <alan@signal11.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
Refuse to create 6lowpan links if the actual hardware interface is
of any type other than ARPHRD_IEEE802154.
Signed-off-by: Alan Ott <alan@signal11.us>
Suggested-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
ip link has ability to show extra information of net work device if
kernel provides sunh information. With this patch veth driver can
provide its peer ifindex information to ip command via netlink
interface.
Signed-off-by: Masatake YAMATO <yamato@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This reverts commit 4f0581d258.
The named changeset is causing problem. Let's aim to make this part less
fragile before trying to improve things.
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Annie Li <annie.li@oracle.com>
Cc: Matt Wilson <msw@amazon.com>
Cc: Xi Xiong <xixiong@amazon.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Paul Durrant <paul.durrant@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
On Tue, 20 Aug 2013 11:40:04 -0500 Eric Sandeen <sandeen@redhat.com> wrote:
> This was brought up in a Red Hat bug (which may be marked private, I'm sorry):
>
> Bug 987055 - open O_WRONLY succeeds on some root owned files in /proc for process running with unprivileged EUID
>
> "On RHEL7 some of the files in /proc can be opened for writing by an unprivileged EUID."
>
> The flaw existed upstream as well last I checked.
>
> This commit in kernel v3.8 caused the regression:
>
> commit cff109768b
> Author: Eric W. Biederman <ebiederm@xmission.com>
> Date: Fri Nov 16 03:03:01 2012 +0000
>
> net: Update the per network namespace sysctls to be available to the network namespace owner
>
> - Allow anyone with CAP_NET_ADMIN rights in the user namespace of the
> the netowrk namespace to change sysctls.
> - Allow anyone the uid of the user namespace root the same
> permissions over the network namespace sysctls as the global root.
> - Allow anyone with gid of the user namespace root group the same
> permissions over the network namespace sysctl as the global root group.
>
> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
> Signed-off-by: David S. Miller <davem@davemloft.net>
>
> because it changed /sys/net's special permission handler to test current_uid, not
> current_euid; same for current_gid/current_egid.
>
> So in this case, root cannot drop privs via set[ug]id, and retains all privs
> in this codepath.
Modify the code to use current_euid(), and in_egroup_p, as in done
in fs/proc/proc_sysctl.c:test_perm()
Cc: stable@vger.kernel.org
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Reported-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch fixes the calculation of the nlmsg size, by adding the missing
nla_total_size().
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch proposes to remove the use of the IRQF_DISABLED flag
It's a NOOP since 2.6.35 and it will be removed one day.
Signed-off-by: Michael Opdenacker <michael.opdenacker@free-electrons.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch proposes to remove the use of the IRQF_DISABLED flag
It's a NOOP since 2.6.35 and it will be removed one day.
Signed-off-by: Michael Opdenacker <michael.opdenacker@free-electrons.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch proposes to remove the use of the IRQF_DISABLED flag
It's a NOOP since 2.6.35 and it will be removed one day.
Signed-off-by: Michael Opdenacker <michael.opdenacker@free-electrons.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch proposes to remove the use of the IRQF_DISABLED flag
It's a NOOP since 2.6.35 and it will be removed one day.
Signed-off-by: Michael Opdenacker <michael.opdenacker@free-electrons.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
There no longer are ISA drivers in the fujitsu directory, so remove the
dependency from the Kconfig.
Signed-off-by: Matthew Whitehead <tedheadster@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Conflicts:
drivers/net/wireless/brcm80211/brcmfmac/dhd_bus.h
drivers/net/wireless/rtlwifi/rtl8188ee/phy.h
drivers/net/wireless/rtlwifi/rtl8192ce/phy.h
drivers/net/wireless/rtlwifi/rtl8192de/phy.h
drivers/net/wireless/rtlwifi/rtl8723ae/phy.h
Just some minor conflicts between the wireless-next changes
and Joe Perches's "extern" removal from function prototypes
in header files.
John W. Linville says:
====================
Regarding the Bluetooth bits, Gustavo says:
"The big work here is from Marcel and Johan. They did a lot of work
in the L2CAP, HCI and MGMT layers. The most important ones are the
addition of a new MGMT command to enable/disable LE advertisement
and the introduction of the HCI user channel to allow applications
to get directly and exclusive access to Bluetooth devices."
As to the ath10k bits, Kalle says:
"Bartosz dropped support for qca98xx hw1.0 hardware from ath10k, it's
just too much to support it. Michal added support for the new firmware
interface. Marek fixed WEP in AP and IBSS mode. Rest of the changes are
minor fixes or cleanups."
And also:
"Major changes are:
* throughput improvements including aligning the RX frames correctly and
optimising HTT layer (Michal)
* remove qca98xx hw1.0 support (Bartosz)
* add support for firmware version 999.999.0.636 (Michal)
* firmware htt statistics support (Kalle)
* fix WEP in AP and IBSS mode (Marek)
* fix a mutex unlock balance in debugfs file (Shafi)
And of course there's a lot of smaller fixes and cleanup."
For the wl12xx bits, Luca says:
"Here are some patches intended for 3.13. Eliad is upstreaming a bunch
of patches that have been pending in the internal tree. Mostly bugfixes
and other small improvements."
Along with that...
Arend and friends bring us a batch of brcmfmac updates, Larry Finger
offers some rtlwifi refactoring, and Sujith sends the usual batch of
ath9k updates. As usual, there are a number of other small updates
from a variety of players as well.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
When sending out multicast messages, the source address in inet->mc_addr is
ignored and rewritten by an autoselected one. This is caused by a typo in
commit 813b3b5db8 ("ipv4: Use caller's on-stack flowi as-is in output
route lookups").
Signed-off-by: Jiri Benc <jbenc@redhat.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Separate the unreg_list and the close_list in dev_close_many preventing
dev_close_many from permuting the unreg_list. The permutations of the
unreg_list have resulted in cases where the loopback device is accessed
it has been freed in code such as dst_ifdown. Resulting in subtle memory
corruption.
This is the second bug from sharing the storage between the close_list
and the unreg_list. The issues that crop up with sharing are
apparently too subtle to show up in normal testing or usage, so let's
forget about being clever and use two separate lists.
v2: Make all callers pass in a close_list to dev_close_many
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Acked-by: Mugunthan V N <mugunthanvnm@ti.com>
Acked-by: Peter Korsgaard <jacmet@sunsite.dk>
Signed-off-by: David S. Miller <davem@davemloft.net>
The current implementation searches the whole DT for nodes named
"slave".
This patch changes it to search only child nodes for slaves.
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Acked-by: Mugunthan V N <mugunthanvnm@ti.com>
Acked-by: Peter Korsgaard <jacmet@sunsite.dk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Although we do not yet enable multiple PFs per port, it is possible
that a board will be reconfigured to enable them while the driver has
not yet been updated to fully support this.
The most obvious problem is that multiple functions may try to set
conflicting link settings. But we will also run into trouble if the
firmware doesn't consider us fully trusted. So, abort probing unless
both the LinkCtrl and Trusted flags are set for this function.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
The (inner) MTU of a ipip6 (IPv4-in-IPv6) tunnel cannot be set below 1280, which is the minimum MTU in IPv6.
However, there should be no IPv6 on the tunnel interface at all, so the IPv6 rules should not apply.
More info at https://bugzilla.kernel.org/show_bug.cgi?id=15530
This patch allows to check the minimum MTU for ipv6 tunnel according to these rules:
-In case the tunnel is configured with ipip6 mode the minimum MTU is 68.
-In case the tunnel is configured with ip6ip6 or any mode the minimum MTU is 1280.
Signed-off-by: Oussama Ghorbel <ou.ghorbel@gmail.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>