This patch makes MIPv6 loadable module named "mip6".

Here is a modprobe.conf(5) example to load it automatically
when user application uses XFRM state for MIPv6:

alias xfrm-type-10-43 mip6
alias xfrm-type-10-60 mip6

Some MIPv6 feature is not included by this modular, however,
it should not be affected to other features like either IPsec
or IPv6 with and without the patch.
We may discuss XFRM, MH (RAW socket) and ancillary data/sockopt
separately for future work.

Loadable features:
* MH receiving check (to send ICMP error back)
* RO header parsing and building (i.e. RH2 and HAO in DSTOPTS)
* XFRM policy/state database handling for RO

These are NOT covered as loadable:
* Home Address flags and its rule on source address selection
* XFRM sub policy (depends on its own kernel option)
* XFRM functions to receive RO as IPv6 extension header
* MH sending/receiving through raw socket if user application
  opens it (since raw socket allows to do so)
* RH2 sending as ancillary data
* RH2 operation with setsockopt(2)
Signed-off-by: NMasahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Kill unnecessary CONFIG_IPV6_MIP6.

o It is redundant for RAW socket to keep MH out with the config then
  it can handle any protocol.
o Clean-up at AH.
Signed-off-by: NMasahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Sent the wrong patch previously.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add a nested compat attribute type that can be used to convert
attributes that contain a structure to nested attributes in a
backwards compatible way.

The attribute looks like this:

struct {
        [ compat contents ]
        struct rtattr {
                .rta_len        = total size,
                .rta_type       = type,
        } rta;
        struct old_structure struct;

        [ nested top-level attribute ]
        struct rtattr {
                .rta_len        = nest size,
                .rta_type       = type,
        } nest_attr;

        [ optional 0 .. n nested attributes ]
        struct rtattr {
                .rta_len        = private attribute len,
                .rta_type       = private attribute typ,
        } nested_attr;
        struct nested_data data;
};

Since both userspace and kernel deal correctly with attributes that are
larger than expected old versions will just parse the compat part and
ignore the rest.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add a nested compat attribute type that can be used to convert
attributes that contain a structure to nested attributes in a
backwards compatible way.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently NAT (and others) that want to modify cloned skbs copy them,
even if in the vast majority of cases its not necessary because the
skb is a clone made by TCP and the portion NAT wants to modify is
actually writable because TCP release the header reference before
cloning.

The problem is that there is no clean way for NAT to find out how
long the writable header area is, so this patch introduces skb->hdr_len
to hold this length. When a headerless skb is cloned skb->hdr_len
is set to the current headroom, for regular clones it is copied from
the original. A new function skb_clone_writable(skb, len) returns
whether the skb is writable up to len bytes from skb->data. To avoid
enlarging the skb the mac_len field is reduced to 16 bit and the
new hdr_len field is put in the remaining 16 bit.

I've done a few rough benchmarks of NAT (not with this exact patch,
but a very similar one). As expected it saves huge amounts of system
time in case of sendfile, bringing it down to basically the same
amount as without NAT, with sendmsg it only helps on loopback,
probably because of the large MTU.

Transmit a 1GB file using sendfile/sendmsg over eth0/lo with and
without NAT:

- sendfile eth0, no NAT:	sys     0m0.388s
- sendfile eth0, NAT:		sys     0m1.835s
- sendfile eth0: NAT + path:	sys     0m0.370s	(~ -80%)

- sendfile lo, no NAT:		sys     0m0.258s
- sendfile lo, NAT:		sys     0m2.609s
- sendfile lo, NAT + patch:	sys     0m0.260s	(~ -90%)

- sendmsg eth0, no NAT:		sys     0m2.508s
- sendmsg eth0, NAT:		sys     0m2.539s
- sendmsg eth0, NAT + patch:	sys     0m2.445s	(no change)

- sendmsg lo, no NAT:		sys	0m2.151s
- sendmsg lo, NAT:		sys     0m3.557s
- sendmsg lo, NAT + patch:	sys     0m2.159s	(~ -40%)

I expect other users can see a similar performance improvement,
packet mangling iptables targets, ipip and ip_gre come to mind ..
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Changes :

- netif_queue_stopped need not be called inside qdisc_restart as
  it has been called already in qdisc_run() before the first skb
  is sent, and in __qdisc_run() after each intermediate skb is
  sent (note : we are the only sender, so the queue cannot get
  stopped while the tx lock was got in the ~LLTX case).

- BUG_ON((int) q->q.qlen < 0) was a relic from old times when -1
  meant more packets are available, and __qdisc_run used to loop
  when qdisc_restart() returned -1. During those days, it was
  necessary to make sure that qlen is never less than zero, since
  __qdisc_run would get into an infinite loop if no packets are on
  the queue and this bug in qdisc was there (and worse - no more
  skbs could ever get queue'd as we hold the queue lock too). With
  Herbert's recent change to return values, this check is not
  required.  Hopefully Herbert can validate this change. If at all
  this is required, it should be added to skb_dequeue (in failure
  case), and not to qdisc_qlen.
Signed-off-by: NKrishna Kumar <krkumar2@in.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

New changes :

- Incorporated Peter Waskiewicz's comments.
- Re-added back one warning message (on driver returning wrong value).

Previous changes :

- Converted to use switch/case code which looks neater.

- "if (ret == NETDEV_TX_LOCKED && lockless)" is buggy, and the lockless
  check should be removed, since driver will return NETDEV_TX_LOCKED only
  if lockless is true and driver has to do the locking. In the original
  code as well as the latest code, this code can result in a bug where
  if LLTX is not set for a driver (lockless == 0) but the driver is written
  wrongly to do a trylock (despite LLTX being set), the driver returns
  LOCKED. But since lockless is zero, the packet is requeue'd instead of
  calling collision code which will issue warning and free up the skb.
  Instead this skb will be retried with this driver next time, and the same
  result will ensue. Removing this check will catch these driver bugs instead
  of hiding the problem. I am keeping this change to readability section
  since :
  	a. it is confusing to check two things as it is; and
  	b. it is difficult to keep this check in the changed 'switch' code.

- Changed some names, like try_get_tx_pkt to dev_dequeue_skb (as that is
  the work being done and easier to understand) and do_dev_requeue to
  dev_requeue_skb, merged handle_dev_cpu_collision and tx_islocked to
  dev_handle_collision (handle_dev_cpu_collision is a small routine with only
  one caller, so there is no need to have two separate routines which also
  results in getting rid of two macros, etc.

- Removed an XXX comment as it should never fail (I suspect this was related
  to batch skb WIP, Jamal ?). Converted some functions to original coding
  style of having the return values and the function name on same line, eg
  prio2list.
Signed-off-by: NKrishna Kumar <krkumar2@in.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

ccid3_hc_tx_send_packet currently returns 0 when the time difference between
current time and t_nom is less than 1000 microseconds.

In this case the packet is sent immediately; but, unlike other packets that can
be emitted on first attempt, it will not have its window counter updated and
its options set as required. This is a bug.

Fix: Require the time difference to be at least 1000 microseconds. The
algorithm then converges: time differences > 1000 microseconds trigger the
timer in dccp_write_xmit; after timer expiry this function is tried again; when
the time difference is less than 1000, the packet will have its options added
and window counter updated as required.
Signed-off-by: NGerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: NArnaldo Carvalho de Melo <acme@ghostprotocols.net>

This updates the computation of t_nom and t_last_win_count to use the newer
gettimeofday interface.

Committer note: used ktime_to_timeval to set the 'now' variable to t_ld in
                ccid3hctx_no_feedback_timer
Signed-off-by: NGerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: NArnaldo Carvalho de Melo <acme@ghostprotocols.net>

Signed-off-by: NArnaldo Carvalho de Melo <acme@ghostprotocols.net>

This provides a reusable time difference function which returns the difference in
microseconds, as often used in the DCCP code.

Commiter note: renamed ktime_delta to ktime_us_delta and put it in ktime.h.
Signed-off-by: NGerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: NArnaldo Carvalho de Melo <acme@ghostprotocols.net>

net/dccp/ccids/lib/loss_interval.c is the only place where this struct is used.
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

It had just a slab cache, so, for the sake of simplicity just make
dccp_trfc_lib module init routine create the slab cache, no need for users of
the lib to create a private loss_interval object.
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Not used outside the loss_interval code anymore.
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Now its only used inside the loss_interval code.
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Renaming it to dccp_li_update_li.

Also based on previous work by Ian McDonald.
Signed-off-by: NArnaldo Carvalho de Melo <acme@ghostprotocols.net>

Now ccid3_hc_rx_update_li is ready to be moved to
net/dccp/ccids/lib/loss_interval, it uses the same interface as the other
functions there.
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

This is a preparatory patch for moving these loss interval functions from
net/dccp/ccids/ccid3.c to net/dccp/ccids/lib/loss_interval.c.

Based on a patch by Ian McDonald.
Signed-off-by: NArnaldo Carvalho de Melo <acme@ghostprotocols.net>

When compiling with EXTRA_CFLAGS=-W noticed that tstamp is not initialised
correctly in dccp_li_calc_first_li.
Signed-off-by: NArnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: NIan McDonald <ian.mcdonald@jandi.co.nz>

When compiling with EXTRA_CFLAGS=-W notice that we have signed/unsigned issue
in dccp.h.
Signed-off-by: NArnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: NIan McDonald <ian.mcdonald@jandi.co.nz>

Signed-off-by: NIan McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: NArnaldo Carvalho de Melo <acme@ghostprotocols.net>

Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Keep track of the number of configured ingress/egress QoS mappings to
avoid iteration while calculating the netlink attribute size.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

skb->priority has only 32 bits and even VLAN uses 32 bit values in its API.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The returned device is unused, return proper error codes instead and avoid
having the ioctl handler guess the error.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Move device registration and configuration of the underlying device to a
seperate function.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Move the checks of the underlying device to a seperate function.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Move group allocation to a seperate function to clean up the code a bit
and allocate groups before registering the device. Device registration
is globally visible and causes netlink events, so we shouldn't fail
afterwards.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Move some device initialization code to new dev->init callback to make
it shareable with netlink. Additionally this fixes a minor bug, dev->iflink
is set after registration, which causes an incorrect value in the initial
netlink message.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Move the device lookup and checks to the ioctl handler under the RTNL and
change all name-based interfaces to take a struct net_device * instead.

This allows to use them from a netlink interface, which identifies devices
based on ifindex not name. It also avoids races between the ioctl interface
and the (upcoming) netlink interface since now all changes happen under the
RTNL.

As a nice side effect this greatly simplifies error handling in the helper
functions and fixes a number of incorrect error codes like -EINVAL for
device not found.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use a list instead of an array to allow creating new devices.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use a list instead of an array to allow creating new devices.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use dev->stats instead of netdev_priv().
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add rtnetlink API for creating, changing and deleting software devices.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Split up rtnl_setlink into a function performing validation and a function
performing the actual changes. This allows to share the modifcation logic
with rtnl_newlink, which is introduced by the next patch.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>