Convert the "simple" qdiscs to use qdisc_tree_decrease_qlen() where
necessary:

- all graft operations
- destruction of old child qdiscs in prio, red and tbf change operation
- purging of queue in sfq change operation
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There are multiple problems related to qlen adjustment that can lead
to an upper qdisc getting out of sync with the real number of packets
queued, leading to endless dequeueing attempts by the upper layer code.

All qdiscs must maintain an accurate q.qlen counter. There are basically
two groups of operations affecting the qlen: operations that propagate
down the tree (enqueue, dequeue, requeue, drop, reset) beginning at the
root qdisc and operations only affecting a subtree or single qdisc
(change, graft, delete class). Since qlen changes during operations from
the second group don't propagate to ancestor qdiscs, their qlen values
become desynchronized.

This patch adds a function to propagate qlen changes up the qdisc tree,
optionally calling a callback function to perform qdisc-internal
maintenance when the child qdisc becomes empty. The follow-up patches
will convert all qdiscs to use this function where necessary.

Noticed by Timo Steinbach <tsteinbach@astaro.com>.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Set parent classids in default qdiscs to allow walking up the tree
from outside the qdiscs. This is needed by the next patch.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

qlen adjustment should happen immediately in ->delete and not in the
class destroy function because the reference count will not hit zero in
->delete (sch_api holds a reference) but in ->put. Since the qdisc
lock is released between deletion of the class and final destruction
this creates an externally visible error in the qlen counter.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NArnaldo Carvalho de Melo <acme@mandriva.com>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Based on patch by Patrick McHardy.

Add a new option, NET_SCH_FIFO, which provides a simple fifo qdisc
without requiring CONFIG_NET_SCHED.

The d80211 stack needs a generic fifo qdisc for WME.  At present it
uses net/d80211/fifo_qdisc.c which is functionally equivalent to
sch_fifo.c.  This patch will allow the d80211 stack to remove
net/d80211/fifo_qdisc.c and use sch_fifo.c instead.
Signed-off-by: NDavid Kimdon <david.kimdon@devicescape.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

nfmark is being used in various subsystems and has become
the defacto mark field for all kinds of packets. Therefore
it makes sense to rename it to `mark' and remove the
dependency on CONFIG_NETFILTER.
Signed-off-by: NThomas Graf <tgraf@suug.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Otherwise we can hit paths that (legally) do multiple deletes on the
same node and OOPS with the HLIST poison values there instead of
NULL.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

I don't want my code to downgraded to GPLv3 because of
cut-n-pasted the comments. These files which I hold copyright
on were started before it was clear what GPLv3 was going to be.
Signed-off-by: NStephen Hemminger <shemminger@osdl.org>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

The networking emulator can queue SKBs for a very long
time, so if you're using netem on the sender side for
large bandwidth/delay product testing, the SKB socket
send queue sizes become artificially larger.

Correct this by calling skb_orphan() in netem_enqueue().
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use rb_first() to get first entry in rb tree.
Signed-off-by: NAkinbou Mita <akinobu.mita@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Remove unused file, estimators live in net/core/gen_estimator.c now.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

With commit 10fd48f2 [1] ,  RB_EMPTY_NODE
changed behaviour so it returns true when the node is empty as expected.
Hence Patrick McHardy's fix for sched_htb.c should be reverted.
Signed-off-by: NIsmail Donmez <ismail@pardus.org.tr>
ACKed-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The move of qdisc destruction to a rcu callback broke locking in the
entire qdisc layer by invalidating previously valid assumptions about
the context in which changes to the qdisc tree occur.

The two assumptions were:

- since changes only happen in process context, read_lock doesn't need
  bottem half protection. Now invalid since destruction of inner qdiscs,
  classifiers, actions and estimators happens in the RCU callback unless
  they're manually deleted, resulting in dead-locks when read_lock in
  process context is interrupted by write_lock_bh in bottem half context.

- since changes only happen under the RTNL, no additional locking is
  necessary for data not used during packet processing (f.e. u32_list).
  Again, since destruction now happens in the RCU callback, this assumption
  is not valid anymore, causing races while using this data, which can
  result in corruption or use-after-free.

Instead of "fixing" this by disabling bottem halfs everywhere and adding
new locks/refcounting, this patch makes these assumptions valid again by
moving destruction back to process context. Since only the dev->qdisc
pointer is protected by RCU, but ->enqueue and the qdisc tree are still
protected by dev->qdisc_lock, destruction of the tree can be performed
immediately and only the final free needs to happen in the rcu callback
to make sure dev_queue_xmit doesn't access already freed memory.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix incorrect use of RB_EMPTY_NODE in htb_safe_rb_erase, which makes it
skip nodes within the rbtree instead of nodes not in the tree, resulting
in crashes later on.

The root cause for this seems to be the very counter-intuitive behaviour
of the RB_EMPTY_NODE macro, which returns _false_ when the node is empty.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Prevents filters from being added if the first generated
handle already exists.
Signed-off-by: NKim Nordlund <kim.nordlund@nokia.com>
Signed-off-by: NThomas Graf <tgraf@suug.ch>

This patch makes the needlessly global struct simp_hash_info static.
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Support masking the nfmark value before the search. The mask value is
global for all filters contained in one instance. It can only be set
when a new instance is created, all filters must specify the same mask.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The size is verified by x_tables and isn't needed by the modules anymore.
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>

This was simply making templates of functions and mostly causing a lot
of code duplication in the classifier action modules.

We solve this more cleanly by having a common "struct tcf_common" that
hash worker functions contained once in act_api.c can work with.

Callers work with real action objects that have the common struct
plus their module specific struct members.  You go from a common
object to the higher level one using a "to_foo()" macro which makes
use of container_of() to do the dirty work.

This also kills off act_generic.h which was only used by act_simple.c
and keeping it around was more work than the it's value.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NThomas Graf <tgraf@suug.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add code to initialize rb tree nodes, and check for double deletion.
This is not a real fix, but I can make it trap sometimes and may
be a bandaid for: http://bugzilla.kernel.org/show_bug.cgi?id=6681Signed-off-by: NStephen Hemminger <shemminger@osdl.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use hlist instead of list for the hash list. This saves
space, and we can check for double delete better.
Signed-off-by: NStephen Hemminger <shemminger@osdl.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Code was a mess in terms of indentation.  Run through Lindent
script, and cleanup the damage. Also, don't use, vim magic
comment, and substitute inline for __inline__.
Signed-off-by: NStephen Hemminger <shemminger@osdl.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Change the conditional compilation around HTB_HYSTERSIS
since code was splitting mid expression.
Signed-off-by: NStephen Hemminger <shemminger@osdl.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Get rid of the macro's being used to obscure the locking.
Signed-off-by: NStephen Hemminger <shemminger@osdl.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The HTB network scheduler had debug code that wouldn't compile
and confused and obfuscated the code, remove it.
Signed-off-by: NStephen Hemminger <shemminger@osdl.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Replace CHECKSUM_HW by CHECKSUM_PARTIAL (for outgoing packets, whose
checksum still needs to be completed) and CHECKSUM_COMPLETE (for
incoming packets, device supplied full checksum).

Patch originally from Herbert Xu, updated by myself for 2.6.18-rc3.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix lockdep warning with GRE, iptables and Speedtouch ADSL, PPP over ATM.

On Sat, Sep 02, 2006 at 08:39:28PM +0000, Krzysztof Halasa wrote:
> 
> =======================================================
> [ INFO: possible circular locking dependency detected ]
> -------------------------------------------------------
> swapper/0 is trying to acquire lock:
>  (&dev->queue_lock){-+..}, at: [<c02c8c46>] dev_queue_xmit+0x56/0x290
> 
> but task is already holding lock:
>  (&dev->_xmit_lock){-+..}, at: [<c02c8e14>] dev_queue_xmit+0x224/0x290
> 
> which lock already depends on the new lock.

This turns out to be a genuine bug.  The queue lock and xmit lock are
intentionally taken out of order.  Two things are supposed to prevent
dead-locks from occuring:

1) When we hold the queue_lock we're supposed to only do try_lock on the
tx_lock.

2) We always drop the queue_lock after taking the tx_lock and before doing
anything else.

> 
> the existing dependency chain (in reverse order) is:
> 
> -> #1 (&dev->_xmit_lock){-+..}:
>        [<c012e7b6>] lock_acquire+0x76/0xa0
>        [<c0336241>] _spin_lock_bh+0x31/0x40
>        [<c02d25a9>] dev_activate+0x69/0x120

This path obviously breaks assumption 1) and therefore can lead to ABBA
dead-locks.

I've looked at the history and there seems to be no reason for the lock
to be held at all in dev_watchdog_up.  The lock appeared in day one and
even there it was unnecessary.  In fact, people added __dev_watchdog_up
precisely in order to get around the tx lock there.

The function dev_watchdog_up is already serialised by rtnl_lock since
its only caller dev_activate is always called under it.

So here is a simple patch to remove the tx lock from dev_watchdog_up.
In 2.6.19 we can eliminate the unnecessary __dev_watchdog_up and
replace it with dev_watchdog_up.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NRalf Hildebrandt <Ralf.Hildebrandt@charite.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Return ENOENT if qdisc module is unavailable
Signed-off-by: NJamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NPanagiotis Issaris <takis@issaris.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

CONFIG_DEBUG_SLAB found the following bug:
netem_enqueue() in sch_netem.c gets a pointer inside a slab object:
struct netem_skb_cb *cb = (struct netem_skb_cb *)skb->cb;
But then, the slab object may be freed:
skb = skb_unshare(skb, GFP_ATOMIC)
cb is still pointing inside the freed skb, so here is a patch to
initialize cb later, and make it clear that initializing it sooner
is a bad idea.

[From Stephen Hemminger: leave cb unitialized in order to let gcc
complain in case of use before initialization]
Signed-off-by: NGuillaume Chazarain <guichaz@yahoo.fr>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/sched/sch_htb.c: In function 'htb_change_class':
net/sched/sch_htb.c:1605: error: expected ';' before 'do_gettimeofday'
Signed-off-by: NDave Jones <davej@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The upper bound for HTB time diff needs to be scaled to PSCHED
units rather than just assuming usecs.  The field mbuffer is used
in TDIFF_SAFE(), as an upper bound.
Signed-off-by: NStephen Hemminger <shemminger@osdl.org>
Acked-by: NJamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Acked-by: NJamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Module reference needs to be given back if message header
construction fails.
Signed-off-by: NThomas Graf <tgraf@suug.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

"return -err" and blindly inheriting the error code in the netlink
failure exception handler causes errors codes to be returned as
positive value therefore making them being ignored by the caller.

May lead to sending out incomplete netlink messages.
Signed-off-by: NThomas Graf <tgraf@suug.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>