This patch introduce a new mib entry which isn't part of 802.15.4 but
useful as default behaviour to set the ack request bit or not if we
don't know if the ack request bit should set. This is currently used for
stacks like IEEE 802.15.4 6LoWPAN.
Reviewed-by: Stefan Schmidt <stefan@osg.samsung.com>
Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

This patch changes the state change behaviour of at86rf230 to always
TX_ARET mode. According the at86rf2xx datasheets TX_ARET mode doesn't
mean to be always waiting for ack frames after transmit. The transceiver
will automatically wait for ack frames or not if the acknowledge request
bit is set. See section "TX_ARET_ON – Transmit with Automatic Frame
Retransmission and CSMA-CA Retry".
Reviewed-by: Stefan Schmidt <stefan@osg.samsung.com>
Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

This patch changes the default minimum value of frame_retries to 0 and
changes the frame_retries default value to 3 which is also 802.15.4
default.

We don't use the frame_retries "-1" value as indicator for no-aret mode
anymore, instead we checking on the ack request bit inside the 802.15.4
frame control field. This allows a acknowledge handling per frame. This
checking is done by transceiver or inside xmit callback of driver layer.

If a transceiver doesn't support ARET handling the transmit
functionality ignores ack frames then, which isn't well but should not
effect anything of current functionality.
Reviewed-by: Stefan Schmidt <stefan@osg.samsung.com>
Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

This patch removes several checks if a value is really changed. This
makes only sense if we have another layer call e.g. calling the
driver_ops which is done by callbacks like "set_channel".

For MAC settings which need to be set by phy registers (if the phy
supports that handling) this is set by doing an interface up currently
and are not direct driver_ops calls, so we remove the checks from these
configuration callbacks.
Reviewed-by: Stefan Schmidt <stefan@osg.samsung.com>
Suggested-by: Phoebe Buckheister <phoebe.buckheister@itwm.fraunhofer.de>
Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

If we currently change the mac address inside the wpan interface while
we have a lowpan interface on top of the wpan interface, the mac address
setting doesn't reach the lowpan interface. The effect would be that the
IPv6 lowpan interface has the old SLAAC address and isn't working
anymore because the lowpan interface use in internal mechanism sometimes
dev->addr which is the old mac address of the wpan interface.

This patch checks if a wpan interface belongs to lowpan interface, if
yes then we need to check if the lowpan interface is down and change the
mac address also at the lowpan interface. When the lowpan interface will
be set up afterwards, it will use the correct SLAAC address which based
on the updated mac address setting.
Reviewed-by: Stefan Schmidt <stefan@osg.samsung.com>
Tested-by: Stefan Schmidt <stefan@osg.samsung.com>
Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

We currently supports multiple lowpan interfaces per wpan interface. I
never saw any use case into such functionality. We drop this feature now
because it's much easier do deal with address changes inside the under
laying wpan interface.

This patch removes the multiple lowpan interface and adds a lowpan_dev
netdev pointer into the wpan_dev, if this pointer isn't null the wpan
interface belongs to the assigned lowpan interface.
Reviewed-by: Stefan Schmidt <stefan@osg.samsung.com>
Tested-by: Stefan Schmidt <stefan@osg.samsung.com>
Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

The lowpan_fetch_skb function is used to fetch the first byte,
which also increments the data pointer in skb structure,
making subsequent array lookup of byte 0 actually being byte 1.

To decompress the first byte of the Flow Label when the TF flag is
set to 0x01, the second half of the first byte is needed.

The patch fixes the extraction of the Flow Label field.
Acked-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Signed-off-by: Lukasz Duda <lukasz.duda@nordicsemi.no>
Signed-off-by: Glenn Ruben Bakke <glenn.ruben.bakke@nordicsemi.no>
Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

We will not release sdio bus until firmware is completely
downloaded and becomes ready. Our 8887 A2 chip can have
separate firmware images for WLAN and bluetooth. This
patch fixes an issue observed when both drivers
simultaneously try to download respective firmwares.
Signed-off-by: Aniket Nagarnaik <aniketn@marvell.com>
Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

We should be passing the pointer itself instead of the address of the
pointer.

This was a copy and paste bug when we replaced the calls to
hci_send_cmd().  Originally, the arguments were "len, cp" but we
overwrote them with "sizeof(cp), &cp" by mistake.

Fixes: b3d39140 ('Bluetooth: Move amp assoc read/write completed callback to amp.c')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

Jiri Pirko says:

====================
mlxsw: Couple of fixes/adjustments

Ido Schimmel (5):
  mlxsw: Call free_netdev when removing port
  mlxsw: Make system port to local port mapping explicit
  mlxsw: Simplify mlxsw_sx_port_xmit function
  mlxsw: Use correct skb length when dumping payload
  mlxsw: Fix use-after-free bug in mlxsw_sx_port_xmit

Jiri Pirko (2):
  mlxsw: Make pci module dependent on HAS_DMA and HAS_IOMEM
  mlxsw: Strip FCS from incoming packets
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Store the length of the skb before transmitting it and use it for stats
instead of skb->len, since skb might have been freed already.

This issue was discovered using the Kernel Address sanitizer (KASan).
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Do not use the length of the transmitted skb (which was freed), but
that of the response skb.

This issue was discovered using the Kernel Address sanitizer (KASan).
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Previously we only checked if the transmission queue is not full in the
middle of the xmit function. This lead to complex logic due to the fact
that sometimes we need to reallocate the headroom for our Tx header.

Allow the switch driver to know if the transmission queue is not full
before sending the packet and remove this complex logic.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

FCS of incoming packets is already checked by HW. Just strip it out.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This resolves compile errors on um-allyesconfig.

Note that there are many other drivers which have the same issue.
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

System ports are unique identifiers in a multi-ASIC environment that
represent all the available ports in the system. Local ports on the
other hand, are unique only within the local ASIC.

Since system port to local port mapping is not part of the HW-SW
contract and since only single-ASIC configurations are currently
supported, set an explicit 1:1 mapping by configuring the Switch System
Port Record (SSPR) register.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When removing a port's netdevice we should also free the memory
allocated by alloc_etherdev(). Do this by calling free_netdev() at the
end of the teardown sequence.
Reported-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch fix double word "the the" in
Documentation/DocBook/networking/API-eth-get-headlen.html
Documentation/DocBook/networking/netdev.html
Documentation/DocBook/networking.xml

These files are generated from comment in source,
so I have to fix comment in net/ethernet/eth.c.
Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

RTL8211DN is compatible with RTL8211E.
Signed-off-by: Shaohui Xie <Shaohui.Xie@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

RFC 4182 s2 states that if an IPv4 Explicit NULL label is the only
label on the stack, then after popping the resulting packet must be
treated as a IPv4 packet and forwarded based on the IPv4 header. The
same is true for IPv6 Explicit NULL with an IPv6 packet following.

Therefore, when installing the IPv4/IPv6 Explicit NULL label routes,
add an attribute that specifies the expected payload type for use at
forwarding time for determining the type of the encapsulated packet
instead of inspecting the first nibble of the packet.
Signed-off-by: Robert Shearman <rshearma@brocade.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Kaixu Xia says:

====================
bpf: Introduce the new ability of eBPF programs to access hardware PMU counter

This patchset is base on the net-next:
 git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git
commit 9dc20a64.

Previous patch v6 url:
https://lkml.org/lkml/2015/8/4/188

changes in V7:
 - rebase the whole patch set to net-next tree(9dc20a64);
 - split out the core perf APIs into Patch 1/5;
 - change the return value of function perf_event_attrs()
   from struct perf_event * to const struct perf_event * in
   Patch 1/5;
 - rename the function perf_event_read_internal() to perf_event_
   read_local() and rewrite it in Patch 1/5;
 - rename the function check_func_limit() to check_map_func
   _compatibility() and remove the unnecessary pass pointer to
   a pointer in Patch 4/5;

changes in V6:
 - make the Patch 1/4 commit message more meaning and readable;
 - remove the unnecessary comment in Patch 2/4 and make it clean;
 - declare the function perf_event_release_kernel() in include/
   linux/perf_event.h to fix the build error when CONFIG_PERF_EVENTS
   isn't configured in Patch 2/4;
 - add function perf_event_attrs() to get the struct perf_event_attr
   in Patch 2/4.
 - move the related code from kernel/trace/bpf_trace.c to kernel/
   events/core.c and add function perf_event_read_internal() to
   avoid poking inside of the event outside of perf code in Patch 3/4;
 - generial the func & map match-pair with an array in Patch 3/4;

changes in V5:
 - move struct fd_array_map_ops* fd_ops to bpf_map;
 - move array perf event decrement refcnt function to
   map_free;
 - fix the NULL ptr of perf_event_get();
 - move bpf_perf_event_read() to kernel/bpf/bpf_trace.c;
 - get rid of the remaining struct bpf_prog;
 - move the unnecessay cast on void *;

changes in V4:
 - make the bpf_prog_array_map more generic;
 - fix the bug of event refcnt leak;
 - use more useful errno in bpf_perf_event_read();

changes in V3:
 - collapse V2 patches 1-3 into one;
 - drop the function map->ops->map_traverse_elem() and release
   the struct perf_event in map_free;
 - only allow to access bpf_perf_event_read() from programs;
 - update the perf_event_array_map elem via xchg();
 - pass index directly to bpf_perf_event_read() instead of
   MAP_KEY;

changes in V2:
 - put atomic_long_inc_not_zero() between fdget() and fdput();
 - limit the event type to PERF_TYPE_RAW and PERF_TYPE_HARDWARE;
 - Only read the event counter on current CPU or on current
   process;
 - add new map type BPF_MAP_TYPE_PERF_EVENT_ARRAY to store the
   pointer to the struct perf_event;
 - according to the perf_event_map_fd and key, the function
   bpf_perf_event_read() can get the Hardware PMU counter value;

Patch 5/5 is a simple example and shows how to use this new eBPF
programs ability. The PMU counter data can be found in
/sys/kernel/debug/tracing/trace(trace_pipe).(the cycles PMU
value when 'kprobe/sys_write' sampling)

  $ cat /sys/kernel/debug/tracing/trace_pipe
  $ ./tracex6
       ...
       syslog-ng-548   [000] d..1    76.905673: : CPU-0   681765271
       syslog-ng-548   [000] d..1    76.905690: : CPU-0   681787855
       syslog-ng-548   [000] d..1    76.905707: : CPU-0   681810504
       syslog-ng-548   [000] d..1    76.905725: : CPU-0   681834771
       syslog-ng-548   [000] d..1    76.905745: : CPU-0   681859519
       syslog-ng-548   [000] d..1    76.905766: : CPU-0   681890419
       syslog-ng-548   [000] d..1    76.905783: : CPU-0   681914045
       syslog-ng-548   [000] d..1    76.905800: : CPU-0   681935950
       syslog-ng-548   [000] d..1    76.905816: : CPU-0   681958299
              ls-690   [005] d..1    82.241308: : CPU-5   3138451
              sh-691   [004] d..1    82.244570: : CPU-4   7324988
           <...>-699   [007] d..1    99.961387: : CPU-7   3194027
           <...>-695   [003] d..1    99.961474: : CPU-3   288901
           <...>-695   [003] d..1    99.961541: : CPU-3   383145
           <...>-695   [003] d..1    99.961591: : CPU-3   450365
           <...>-695   [003] d..1    99.961639: : CPU-3   515751
           <...>-695   [003] d..1    99.961686: : CPU-3   579047
       ...

The detail of patches is as follow:

Patch 1/5 add the necessary core perf APIs perf_event_attrs(),
perf_event_get(),perf_event_read_local() when accessing events
counters in eBPF programs

Patch 2/5 rewrites part of the bpf_prog_array map code and make it
more generic;

Patch 3/5 introduces a new bpf map type. This map only stores the
pointer to struct perf_event;

Patch 4/5 implements function bpf_perf_event_read() that get the
selected hardware PMU conuter;

Patch 5/5 gives a simple example.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

This is a simple example and shows how to use the new ability
to get the selected Hardware PMU counter value.
Signed-off-by: Kaixu Xia <xiakaixu@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

According to the perf_event_map_fd and index, the function
bpf_perf_event_read() can convert the corresponding map
value to the pointer to struct perf_event and return the
Hardware PMU counter value.
Signed-off-by: Kaixu Xia <xiakaixu@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Introduce a new bpf map type 'BPF_MAP_TYPE_PERF_EVENT_ARRAY'.
This map only stores the pointer to struct perf_event. The
user space event FDs from perf_event_open() syscall are converted
to the pointer to struct perf_event and stored in map.
Signed-off-by: Kaixu Xia <xiakaixu@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

All the map backends are of generic nature. In order to avoid
adding much special code into the eBPF core, rewrite part of
the bpf_prog_array map code and make it more generic. So the
new perf_event_array map type can reuse most of code with
bpf_prog_array map and add fewer lines of special code.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Signed-off-by: Kaixu Xia <xiakaixu@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch add three core perf APIs:
 - perf_event_attrs(): export the struct perf_event_attr from struct
   perf_event;
 - perf_event_get(): get the struct perf_event from the given fd;
 - perf_event_read_local(): read the events counters active on the
   current CPU;
These APIs are needed when accessing events counters in eBPF programs.

The API perf_event_read_local() comes from Peter and I add the
corresponding SOB.
Signed-off-by: Kaixu Xia <xiakaixu@huawei.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: David S. Miller <davem@davemloft.net>

Vivien Didelot says:

====================
net: dsa: mv88e6xxx: support switchdev FDB objects

This patchset refactors the DSA and mv88e6xxx code to use the switchdev FDB
objects.

The first two patches add minor but necessary changes to switchdev, the third
one implements the switchdev glue in DSA for FDB routines, and the remaining
ones refactor the FDB access functions in the mv88e6xxx code.

Below is an usage example (ports 0-2 belongs to br0, ports 3-4 belongs to br1):

    # bridge fdb add 3c:97:0e:11:30:6e dev swp2
    # bridge fdb add 3c:97:0e:11:40:78 dev swp3
    # bridge fdb add 3c:97:0e:11:50:86 dev swp4
    # bridge fdb del 3c:97:0e:11:40:78 dev swp3
    # bridge fdb
    01:00:5e:00:00:01 dev eth0 self permanent
    01:00:5e:00:00:01 dev eth1 self permanent
    00:50:d2:10:78:15 dev swp0 master br0 permanent
    3c:97:0e:11:30:6e dev swp2 self static
    00:50:d2:10:78:15 dev swp3 master br1 permanent
    3c:97:0e:11:50:86 dev swp4 self static
    # cat /sys/kernel/debug/dsa0/atu
    # DB   T/P  Vec State Addr
    # 001  Port 004   e   3c:97:0e:11:30:6e
    # 004  Port 010   e   3c:97:0e:11:50:86

For the 88E6xxx switches, FIDs 1 to num_ports will be reserved for non-bridged
ports and bridge groups, and the remaining will be later used by VLANs.

This change is necessary to welcome the support for hardware VLANs (which will
follow soon).

Changes in v2:

 - remove ndo_bridge_{get,set,del}link from switchdev/DSA glue code

 - use ether_addr_copy instead of memcpy for MAC addresses

 - constify MAC address in port_fdb_{add,del}

 - split the mv88e6xxx code refactoring into several patches
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Add a low level function for the ATU Load operation, and provide FDB add
and delete wrappers functions.
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This commit adds a low level _mv88e6xxx_atu_getnext function and helpers
to rewrite the mv88e6xxx_port_fdb_getnext operation.

A mv88e6xxx_atu_entry structure is added for convenient access to the
hardware, and GLOBAL_ATU_FID is defined instead of the raw 0x01 value.

The previous implementation did not handle the eventual trunk mapping.
If the related bit is set, then the ATU data register would contain the
trunk ID, and not the port vector.

Check this in the FDB getnext operation and do not handle it (yet).
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Rename the __mv88e6xxx_{read,write}_addr functions to more explicit
_mv88e6xxx_atu_mac_{read,write} functions, which also respect the single
underscore convention used in the file (meaning SMI lock must be held).

In the meantime, define their MAC address parameters as an array of
ETH_ALEN bytes instead of a char pointer.
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The driver currently manages one FID per port (or bridge group), with a
mask of DSA_MAX_PORTS bits, where 0 means that the FID is in use.

The Marvell 88E6xxx switches support up to 4094 FIDs (from 1 to 0xfff;
FID 0 means that multiple address databases are not being used).

This patch changes the fid_mask for an fid_bitmap of 4096 bits.

>From now on, FIDs 1 to num_ports are reserved for non-bridged ports and
bridge groups (a bridge group gets the FID of its first member). The
remaining bits will be reserved for VLAN entries.
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Remove the fdb_{add,del,getnext} function pointer in favor of new
port_fdb_{add,del,getnext}.

Implement the switchdev_port_obj_{add,del,dump} functions in DSA to
support the SWITCHDEV_OBJ_PORT_FDB objects.
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch adds a is_static boolean to the switchdev_obj_fdb structure,
in order to set the ndm_state to either NUD_NOARP or NUD_REACHABLE.
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The address in the switchdev_obj_fdb structure is currently represented
as a pointer. Replacing it for a 6-byte array allows switchdev to carry
addresses directly read from hardware registers, not stored by the
switch chip driver (as in Rocker).
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch fix a double word "the the"
in Documentation/DocBook/networking.xml and
Documentation/DocBook/networking/API-Wimax-report-rfkill-sw.html.

These files are generated from comment in source, so I had to
fix the typo in net/wimax/io-rfkill.c
Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

There is a race condition in store_rps_map that allows jump label
count in rps_needed to go below zero. This can happen when
concurrently attempting to set and a clear map.

Scenario:

1. rps_needed count is zero
2. New map is assigned by setting thread, but rps_needed count _not_ yet
   incremented (rps_needed count still zero)
2. Map is cleared by second thread, old_map set to that just assigned
3. Second thread performs static_key_slow_dec, rps_needed count now goes
   negative

Fix is to increment or decrement rps_needed under the spinlock.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When sampling rate is 1, the sampling probability is UINT32_MAX. The packet
should be sampled even the prandom32() generate the number of UINT32_MAX.
And none packet need be sampled when the probability is 0.
Signed-off-by: Wenyu Zhang <wenyuz@vmware.com>
Acked-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

IFLA_VXLAN_FLOWBASED is useless without IFLA_VXLAN_COLLECT_METADATA,
so combine them into single IFLA_VXLAN_COLLECT_METADATA flag.
'flowbased' doesn't convey real meaning of the vxlan tunnel mode.
This mode can be used by routing, tc+bpf and ovs.
Only ovs is strictly flow based, so 'collect metadata' is a better
name for this tunnel mode.
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Acked-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Sowmini Varadhan says:

====================
RDS-TCP: Network namespace support

This patch series contains the set of changes to correctly set up
the infra for PF_RDS sockets that use TCP as the transport in multiple
network namespaces.

Patch 1 in the series is the minimal set of changes to allow
a single instance of RDS-TCP to run in any (i.e init_net or other) net
namespace.  The changes in this patch set ensure that the execution of
'modprobe [-r] rds_tcp' sets up the kernel TCP sockets
relative to the current netns, so that RDS applications can send/recv
packets from that netns, and the netns can later be deleted cleanly.

Patch 2 of the series further allows multiple RDS-TCP instances,
one per network namespace. The changes in this patch allows dynamic
creation/tear-down of RDS-TCP client and server sockets  across all
current and future namespaces.

v2 changes from RFC sent out earlier:
    David Ahern comments in patch 1, net_device notifier in patch 2,
    patch 3 broken off and submitted separately.
v3: Cong Wang review comments.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Register pernet subsys init/stop functions that will set up
and tear down per-net RDS-TCP listen endpoints. Unregister
pernet subusys functions on 'modprobe -r' to clean up these
end points.

Enable keepalive on both accept and connect socket endpoints.
The keepalive timer expiration will ensure that client socket
endpoints will be removed as appropriate from the netns when
an interface is removed from a namespace.

Register a device notifier callback that will clean up all
sockets (and thus avoid the need to wait for keepalive timeout)
when the loopback device is unregistered from the netns indicating
that the netns is getting deleted.
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>