IP_ROUTE_CLASSID depends on INET and NET_CLS_ROUTE4 selects
IP_ROUTE_CLASSID, but when INET is not enabled, this kconfig warning
is produced, so fix it by making NET_CLS_ROUTE4 depend on INET.

warning: (NET_CLS_ROUTE4) selects IP_ROUTE_CLASSID which has unmet direct dependencies (NET && INET)

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This is an implementation of the Quick Fair Queue scheduler developed
by Fabio Checconi. The same algorithm is already implemented in ipfw
in FreeBSD. Fabio had an earlier version developed on Linux, I just
cleaned it up.  Thanks to Eric Dumazet for testing this under load.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This is the Stochastic Fair Blue scheduler, based on work from :

W. Feng, D. Kandlur, D. Saha, K. Shin. Blue: A New Class of Active Queue
Management Algorithms. U. Michigan CSE-TR-387-99, April 1999.

http://www.thefengs.com/wuchang/blue/CSE-TR-387-99.pdf

This implementation is based on work done by Juliusz Chroboczek

General SFB algorithm can be found in figure 14, page 15:

B[l][n] : L x N array of bins (L levels, N bins per level)
enqueue()
Calculate hash function values h{0}, h{1}, .. h{L-1}
Update bins at each level
for i = 0 to L - 1
   if (B[i][h{i}].qlen > bin_size)
      B[i][h{i}].p_mark += p_increment;
   else if (B[i][h{i}].qlen == 0)
      B[i][h{i}].p_mark -= p_decrement;
p_min = min(B[0][h{0}].p_mark ... B[L-1][h{L-1}].p_mark);
if (p_min == 1.0)
    ratelimit();
else
    mark/drop with probabilty p_min;

I did the adaptation of Juliusz code to meet current kernel standards,
and various changes to address previous comments :

http://thread.gmane.org/gmane.linux.network/90225
http://thread.gmane.org/gmane.linux.network/90375

Default flow classifier is the rxhash introduced by RPS in 2.6.35, but
we can use an external flow classifier if wanted.

tc qdisc add dev $DEV parent 1:11 handle 11:  \
        est 0.5sec 2sec sfb limit 128

tc filter add dev $DEV protocol ip parent 11: handle 3 \
        flow hash keys dst divisor 1024

Notes:

1) SFB default child qdisc is pfifo_fast. It can be changed by another
qdisc but a child qdisc MUST not drop a packet previously queued. This
is because SFB needs to handle a dequeued packet in order to maintain
its virtual queue states. pfifo_head_drop or CHOKe should not be used.

2) ECN is enabled by default, unlike RED/CHOKe/GRED

With help from Patrick McHardy & Andi Kleen

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Juliusz Chroboczek <Juliusz.Chroboczek@pps.jussieu.fr>
CC: Stephen Hemminger <shemminger@vyatta.com>
CC: Patrick McHardy <kaber@trash.net>
CC: Andi Kleen <andi@firstfloor.org>
CC: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

CHOKe ("CHOose and Kill" or "CHOose and Keep") is an alternative
packet scheduler based on the Random Exponential Drop (RED) algorithm.

The core idea is:
  For every packet arrival:
  	Calculate Qave
	if (Qave < minth)
	     Queue the new packet
	else
	     Select randomly a packet from the queue
	     if (both packets from same flow)
	     then Drop both the packets
	     else if (Qave > maxth)
	          Drop packet
	     else
	       	  Admit packet with proability p (same as RED)

See also:
  Rong Pan, Balaji Prabhakar, Konstantinos Psounis, "CHOKe: a stateless active
   queue management scheme for approximating fair bandwidth allocation",
  Proceeding of INFOCOM'2000, March 2000.

Help from:
     Eric Dumazet <eric.dumazet@gmail.com>
     Patrick McHardy <kaber@trash.net>

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This implements a mqprio queueing discipline that by default creates
a pfifo_fast qdisc per tx queue and provides the needed configuration
interface.

Using the mqprio qdisc the number of tcs currently in use along
with the range of queues alloted to each class can be configured. By
default skbs are mapped to traffic classes using the skb priority.
This mapping is configurable.

Configurable parameters,

struct tc_mqprio_qopt {
	__u8    num_tc;
	__u8    prio_tc_map[TC_BITMASK + 1];
	__u8    hw;
	__u16   count[TC_MAX_QUEUE];
	__u16   offset[TC_MAX_QUEUE];
};

Here the count/offset pairing give the queue alignment and the
prio_tc_map gives the mapping from skb->priority to tc.

The hw bit determines if the hardware should configure the count
and offset values. If the hardware bit is set then the operation
will fail if the hardware does not implement the ndo_setup_tc
operation. This is to avoid undetermined states where the hardware
may or may not control the queue mapping. Also minimal bounds
checking is done on the count/offset to verify a queue does not
exceed num_tx_queues and that queue ranges do not overlap. Otherwise
it is left to user policy or hardware configuration to create
useful mappings.

It is expected that hardware QOS schemes can be implemented by
creating appropriate mappings of queues in ndo_tc_setup().

One expected use case is drivers will use the ndo_setup_tc to map
queue ranges onto 802.1Q traffic classes. This provides a generic
mechanism to map network traffic onto these traffic classes and
removes the need for lower layer drivers to know specifics about
traffic types.

Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix dependencies of netfilter realm match: it depends on NET_CLS_ROUTE,
which itself depends on NET_SCHED; this dependency is missing from netfilter.

Since matching on realms is also useful without having NET_SCHED enabled and
the option really only controls whether the tclassid member is included in
route and dst entries, rename the config option to IP_ROUTE_CLASSID and move
it outside of traffic scheduling context to get rid of the NET_SCHED dependeny.

Reported-by: Vladis Kletnieks <Valdis.Kletnieks@vt.edu>
Signed-off-by: Patrick McHardy <kaber@trash.net>

Some of the documentation refers to web pages under
the domain `osdl.org'. However, `osdl.org' now
redirects to `linuxfoundation.org'.

Rather than rely on redirections, this patch updates
the addresses appropriately; for the most part, only
documentation that is meant to be current has been
updated.

The patch should be pretty quick to scan and check;
each new web-page url was gotten by trying out the
original URL in a browser and then simply copying the
the redirected URL (formatting as necessary).

There is some conflict as to which one of these domain
names is preferred:

  linuxfoundation.org
  linux-foundation.org

So, I wrote:

  info@linuxfoundation.org

and got this reply:

  Message-ID: <4CE17EE6.9040807@linuxfoundation.org>
  Date: Mon, 15 Nov 2010 10:41:42 -0800
  From: David Ames <david@linuxfoundation.org>

  ...

  linuxfoundation.org is preferred. The canonical name for our web site is
  www.linuxfoundation.org. Our list site is actually
  lists.linux-foundation.org.

  Regarding email linuxfoundation.org is preferred there are a few people
  who choose to use linux-foundation.org for their own reasons.

Consequently, I used `linuxfoundation.org' for web pages and
`lists.linux-foundation.org' for mailing-list web pages and email addresses;
the only personal email address I updated from `@osdl.org' was that of
Andrew Morton, who prefers `linux-foundation.org' according `git log'.

Signed-off-by: Michael Witten <mfwitten@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

It uses ip_send_check() and stuff like that.

Reported-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>