Computing the rank of the first set bit in the hash mask (for using later
in u32_hash_fold()) was done with plain C code. Using ffs() instead makes
the code more readable and improves performance (since ffs() is better
optimized in assembler).
Using the conditional operator on hash mask before applying ntohl() also
saves one ntohl() call if mask is 0.
Signed-off-by: Radu Rendec <radu.rendec@ines.ro>
Signed-off-by: Jarek Poplawski <jarkao2@o2.pl>
Acked-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>
While trying to implement u32 hashes in my shaping machine I ran into
a possible bug in the u32 hash/bucket computing algorithm
(net/sched/cls_u32.c).
The problem occurs only with hash masks that extend over the octet
boundary, on little endian machines (where htonl() actually does
something).
Let's say that I would like to use 0x3fc0 as the hash mask. This means
8 contiguous "1" bits starting at b6. With such a mask, the expected
(and logical) behavior is to hash any address in, for instance,
192.168.0.0/26 in bucket 0, then any address in 192.168.0.64/26 in
bucket 1, then 192.168.0.128/26 in bucket 2 and so on.
This is exactly what would happen on a big endian machine, but on
little endian machines, what would actually happen with current
implementation is 0x3fc0 being reversed (into 0xc03f0000) by htonl()
in the userspace tool and then applied to 192.168.x.x in the u32
classifier. When shifting right by 16 bits (rank of first "1" bit in
the reversed mask) and applying the divisor mask (0xff for divisor
256), what would actually remain is 0x3f applied on the "168" octet of
the address.
One could say is this can be easily worked around by taking endianness
into account in userspace and supplying an appropriate mask (0xfc03)
that would be turned into contiguous "1" bits when reversed
(0x03fc0000). But the actual problem is the network address (inside
the packet) not being converted to host order, but used as a
host-order value when computing the bucket.
Let's say the network address is written as n31 n30 ... n0, with n0
being the least significant bit. When used directly (without any
conversion) on a little endian machine, it becomes n7 ... n0 n8 ..n15
etc in the machine's registers. Thus bits n7 and n8 would no longer be
adjacent and 192.168.64.0/26 and 192.168.128.0/26 would no longer be
consecutive.
The fix is to apply ntohl() on the hmask before computing fshift,
and in u32_hash_fold() convert the packet data to host order before
shifting down by fshift.
With helpful feedback from Jamal Hadi Salim and Jarek Poplawski.
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix a bunch of sparse warnings. Mostly about 0 used as
NULL pointer, and shadowed variable declarations.
One notable case was that hash size should have been unsigned.
Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The NET_CLS_ACT option is now a full replacement for NET_CLS_POLICE,
remove the old code. The config option will be kept around to select
the equivalent NET_CLS_ACT options for a short time to allow easier
upgrades.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Spring cleaning time...
There seems to be a lot of places in the network code that have
extra bogus semicolons after conditionals. Most commonly is a
bogus semicolon after: switch() { }
Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
So that it is also an offset from skb->head, reduces its size from 8 to 4 bytes
on 64bit architectures, allowing us to combine the 4 bytes hole left by the
layer headers conversion, reducing struct sk_buff size to 256 bytes, i.e. 4
64byte cachelines, and since the sk_buff slab cache is SLAB_HWCACHE_ALIGN...
:-)
Many calculations that previously required that skb->{transport,network,
mac}_header be first converted to a pointer now can be done directly, being
meaningful as offsets or pointers.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
For the places where we need a pointer to the network header, it is still legal
to touch skb->nh.raw directly if just adding to, subtracting from or setting it
to another layer header.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
After Al Viro (finally) succeeded in removing the sched.h #include in module.h
recently, it makes sense again to remove other superfluous sched.h includes.
There are quite a lot of files which include it but don't actually need
anything defined in there. Presumably these includes were once needed for
macros that used to live in sched.h, but moved to other header files in the
course of cleaning it up.
To ease the pain, this time I did not fiddle with any header files and only
removed #includes from .c-files, which tend to cause less trouble.
Compile tested against 2.6.20-rc2 and 2.6.20-rc2-mm2 (with offsets) on alpha,
arm, i386, ia64, mips, powerpc, and x86_64 with allnoconfig, defconfig,
allmodconfig, and allyesconfig as well as a few randconfigs on x86_64 and all
configs in arch/arm/configs on arm. I also checked that no new warnings were
introduced by the patch (actually, some warnings are removed that were emitted
by unnecessarily included header files).
Signed-off-by: Tim Schmielau <tim@physik3.uni-rostock.de>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
In both cases n can't be NULL without crashing anyway.
Coverity #78
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
From: Jesper Juhl <jesper.juhl@gmail.com>
This is the net/ part of the big kfree cleanup patch.
Remove pointless checks for NULL prior to calling kfree() in net/.
Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Arnaldo Carvalho de Melo <acme@conectiva.com.br>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Acked-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
