Commit Graph

144 Commits

Author SHA1 Message Date
Peter Zijlstra
654bed16cf net: packet split receive api
Add some packet-split receive hooks.

For one this allows to do NUMA node affine page allocs. Later on these
hooks will be extended to do emergency reserve allocations for
fragments.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-07 14:22:33 -07:00
Herbert Xu
4edd87ad5c net: BUG instead of corrupting memory in pskb_expand_head
If the caller of pskb_expand_head specifies a negative nhead
we'll silently overwrite other people's memory.  This patch
makes it BUG instead.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-01 07:09:38 -07:00
Lennert Buytenhek
04a4bb55bc net: add skb_recycle_check() to enable netdriver skb recycling
This patch adds skb_recycle_check(), which can be used by a network
driver after transmitting an skb to check whether this skb can be
recycled as a receive buffer.

skb_recycle_check() checks that the skb is not shared or cloned, and
that it is linear and its head portion large enough (as determined by
the driver) to be recycled as a receive buffer.  If these conditions
are met, it does any necessary reference count dropping and cleans
up the skbuff as if it just came from __alloc_skb().

Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-01 02:33:12 -07:00
Herbert Xu
6f85a124d8 net: Preserve netfilter attributes in skb_gso_segment using __copy_skb_header
skb_gso_segment didn't preserve some attributes in the original skb
such as the netfilter fields.  This was harmless until they were used
which is the case for packets going through lo.

This patch makes it call __copy_skb_header which also picks up some
other missing attributes.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-08-15 19:51:36 -07:00
Johannes Berg
d0f0980414 mac80211: partially fix skb->cb use
This patch fixes mac80211 to not use the skb->cb over the queue step
from virtual interfaces to the master. The patch also, for now,
disables aggregation because that would still require requeuing,
will fix that in a separate patch. There are two other places (software
requeue and powersaving stations) where requeue can happen, but that is
not currently used by any drivers/not possible to use respectively.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-07-29 16:55:08 -04:00
Ilpo Järvinen
547b792cac net: convert BUG_TRAP to generic WARN_ON
Removes legacy reinvent-the-wheel type thing. The generic
machinery integrates much better to automated debugging aids
such as kerneloops.org (and others), and is unambiguous due to
better naming. Non-intuively BUG_TRAP() is actually equal to
WARN_ON() rather than BUG_ON() though some might actually be
promoted to BUG_ON() but I left that to future.

I could make at least one BUILD_BUG_ON conversion.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-25 21:43:18 -07:00
Harvey Harrison
7b1c65faa2 net: make __skb_splice_bits static
net/core/skbuff.c:1335:5: warning: symbol '__skb_splice_bits' was not declared. Should it be static?

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-16 20:12:30 -07:00
Octavian Purdila
2870c43d17 net: refactor tcp splice receive path to improve readability
- move all of the details on offsets, lengths and buffers into a
single function instead of doing these operation from multiple places

- use a bottom up approach: try to avoid details in the high level
functions, introduce them gradually as we go deeper in the function
call stack

With helpful feedback from Jarek Poplawski.

Signed-off-by: Octavian Purdila <opurdila@ixiacom.com>
Acked-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-15 00:49:11 -07:00
Patrick McHardy
6aa895b047 vlan: Don't store VLAN tag in cb
Use a real skb member to store the skb to avoid clashes with qdiscs,
which are allowed to use the cb area themselves. As currently only real
devices that consume the skb set the NETIF_F_HW_VLAN_TX flag, no explicit
invalidation is neccessary.

The new member fills a hole on 64 bit, the skb layout changes from:

        __u32                      mark;                 /*   172     4 */
        sk_buff_data_t             transport_header;     /*   176     4 */
        sk_buff_data_t             network_header;       /*   180     4 */
        sk_buff_data_t             mac_header;           /*   184     4 */
        sk_buff_data_t             tail;                 /*   188     4 */
        /* --- cacheline 3 boundary (192 bytes) --- */
        sk_buff_data_t             end;                  /*   192     4 */

        /* XXX 4 bytes hole, try to pack */

to

        __u32                      mark;                 /*   172     4 */
        __u16                      vlan_tci;             /*   176     2 */

        /* XXX 2 bytes hole, try to pack */

        sk_buff_data_t             transport_header;     /*   180     4 */
        sk_buff_data_t             network_header;       /*   184     4 */

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-14 22:49:06 -07:00
David S. Miller
1b63ba8a86 Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:

	drivers/net/wireless/iwlwifi/iwl4965-base.c
2008-06-28 01:19:40 -07:00
Octavian Purdila
db43a282d3 tcp: fix for splice receive when used with software LRO
If an skb has nr_frags set to zero but its frag_list is not empty (as
it can happen if software LRO is enabled), and a previous
tcp_read_sock has consumed the linear part of the skb, then
__skb_splice_bits:

(a) incorrectly reports an error and

(b) forgets to update the offset to account for the linear part

Any of the two problems will cause the subsequent __skb_splice_bits
call (the one that handles the frag_list skbs) to either skip data,
or, if the unadjusted offset is greater then the size of the next skb
in the frag_list, make tcp_splice_read loop forever.

Signed-off-by: Octavian Purdila <opurdila@ixiacom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-06-27 17:27:21 -07:00
Ben Hutchings
4497b0763c net: Discard and warn about LRO'd skbs received for forwarding
Add skb_warn_if_lro() to test whether an skb was received with LRO and
warn if so.

Change br_forward(), ip_forward() and ip6_forward() to call it) and
discard the skb if it returns true.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-06-19 16:22:28 -07:00
Adrian Bunk
0b04082995 net: remove CVS keywords
This patch removes CVS keywords that weren't updated for a long time
from comments.

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-06-11 21:00:38 -07:00
Octavian Purdila
293ad60401 tcp: Fix for race due to temporary drop of the socket lock in skb_splice_bits.
skb_splice_bits temporary drops the socket lock while iterating over
the socket queue in order to break a reverse locking condition which
happens with sendfile. This, however, opens a window of opportunity
for tcp_collapse() to aggregate skbs and thus potentially free the
current skb used in skb_splice_bits and tcp_read_sock.

This patch fixes the problem by (re-)getting the same "logical skb"
after the lock has been temporary dropped.

Based on idea and initial patch from Evgeniy Polyakov.

Signed-off-by: Octavian Purdila <opurdila@ixiacom.com>
Acked-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-06-04 15:45:58 -07:00
Johannes Berg
c800578510 net: Fix useless comment reference loop.
include/linux/skbuff.h says:
        /* These elements must be at the end, see alloc_skb() for details.  */

net/core/skbuff.c says:
	* See comment in sk_buff definition, just before the 'tail' member

This patch contains my guess as to the actual reason rather than a
dead comment reference loop.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-05-03 20:56:42 -07:00
David S. Miller
df39e8ba56 Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:

	drivers/net/ehea/ehea_main.c
	drivers/net/wireless/iwlwifi/Kconfig
	drivers/net/wireless/rt2x00/rt61pci.c
	net/ipv4/inet_timewait_sock.c
	net/ipv6/raw.c
	net/mac80211/ieee80211_sta.c
2008-04-14 02:30:23 -07:00
Gerrit Renker
7de6c03336 [SKB]: __skb_append = __skb_queue_after
This expresses __skb_append in terms of __skb_queue_after, exploiting that

  __skb_append(old, new, list) = __skb_queue_after(list, old, new).

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-14 00:05:09 -07:00
Ben Hutchings
4c821d753d [NET]: Fix kernel-doc for skb_segment
The kernel-doc comment for skb_segment is clearly wrong.  This states
what it actually does.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-13 21:52:48 -07:00
David S. Miller
a0f55e0e83 [NET]: Fix dev_alloc_skb() typo.
Noticed by Joe Perches.

Signed-off-by: David S. Miller <davem@davemloft.net>
2008-03-28 18:22:32 -07:00
Denys Vlasenko
1483b8744e [NET]: Add inline intent commentary to dev_alloc_skb().
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-03-28 15:57:39 -07:00
Ilpo Järvinen
419ae74ecc [NET]: uninline skb_trim, de-bloats
Allyesconfig (v2.6.24-mm1):
-10976  209 funcs, 123 +, 11099 -, diff: -10976 --- skb_trim

Without number of debug related CONFIGs (v2.6.25-rc2-mm1):
-7360  192 funcs, 131 +, 7491 -, diff: -7360 --- skb_trim
skb_trim                      |  +42

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-03-27 17:54:01 -07:00
Ilpo Järvinen
c2aa270ad7 [NET]: uninline skb_push, de-bloats a lot
Allyesconfig (v2.6.24-mm1):

-21593  356 funcs, 2418 +, 24011 -, diff: -21593 --- skb_push

Without many debug related CONFIGs (v2.6.25-rc2-mm1):

-13890  341 funcs, 189 +, 14079 -, diff: -13890 --- skb_push
skb_push                      |  +46

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-03-27 17:52:40 -07:00
Ilpo Järvinen
f58518e678 [NET]: uninline dev_alloc_skb, de-bloats a lot
Allyesconfig (v2.6.24-mm1):

-23668  392 funcs, 104 +, 23772 -, diff: -23668 --- dev_alloc_skb

Without many debug CONFIGs (v2.6.25-rc2-mm1):

-12178  382 funcs, 157 +, 12335 -, diff: -12178 --- dev_alloc_skb
dev_alloc_skb                 |  +37

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-03-27 17:51:31 -07:00
Ilpo Järvinen
6be8ac2fdc [NET]: uninline skb_pull, de-bloats a lot
Allyesconfig (v2.6.24-mm1):

-28162  354 funcs, 3005 +, 31167 -, diff: -28162 --- skb_pull

Without number of debug related CONFIGs (v2.6.25-rc2-mm1):

-9697  338 funcs, 221 +, 9918 -, diff: -9697 --- skb_pull
skb_pull                      |  +44

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-03-27 17:47:24 -07:00
Ilpo Järvinen
0dde3e1648 [NET]: uninline skb_put, de-bloats a lot
Allyesconfig (v2.6.24-mm1):

~500 files changed
...
 869 funcs, 198 +, 111003 -, diff: -110805 --- skb_put
  skb_put                       | +104

Without number of debug related CONFIGs (v2.6.25-rc2-mm1):

-60744  855 funcs, 861 +, 61605 -, diff: -60744 --- skb_put
  skb_put                       |  +57

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-03-27 17:43:41 -07:00
Linus Torvalds
f6866fecd6 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (82 commits)
  [NET]: Make sure sockets implement splice_read
  netconsole: avoid null pointer dereference at show_local_mac()
  [IPV6]: Fix reversed local_df test in ip6_fragment
  [XFRM]: Avoid bogus BUG() when throwing new policy away.
  [AF_KEY]: Fix bug in spdadd
  [NETFILTER] nf_conntrack_proto_tcp.c: Mistyped state corrected.
  net: xfrm statistics depend on INET
  [NETFILTER]: make secmark_tg_destroy() static
  [INET]: Unexport inet_listen_wlock
  [INET]: Unexport __inet_hash_connect
  [NET]: Improve cache line coherency of ingress qdisc
  [NET]: Fix race in dev_close(). (Bug 9750)
  [IPSEC]: Fix bogus usage of u64 on input sequence number
  [RTNETLINK]: Send a single notification on device state changes.
  [NETLABLE]: Hide netlbl_unlabel_audit_addr6 under ifdef CONFIG_IPV6.
  [NETLABEL]: Don't produce unused variables when IPv6 is off.
  [NETLABEL]: Compilation for CONFIG_AUDIT=n case.
  [GENETLINK]: Relax dances with genl_lock.
  [NETLABEL]: Fix lookup logic of netlbl_domhsh_search_def.
  [IPV6]: remove unused method declaration (net/ndisc.h).
  ...
2008-02-15 07:33:07 -08:00
Randy Dunlap
bc2cda1ebd docbook: make a networking book and fix a few errors
Move networking (core and drivers) docbook to its own networking book.
Fix a few kernel-doc errors in header and source files.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Neil Brown <neilb@suse.de>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-13 16:21:19 -08:00
Urs Thuermann
fee54fa517 [NET]: Fix comment for skb_pull_rcsum
Fix comment for skb_pull_rcsum

Signed-off-by: Urs Thuermann <urs@isnogud.escape.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-02-12 22:03:25 -08:00
Rusty Russell
f35d9d8aae virtio: Implement skb_partial_csum_set, for setting partial csums on untrusted packets.
Use it in virtio_net (replacing buggy version there), it's also going
to be used by TAP for partial csum support.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: David S. Miller <davem@davemloft.net>
2008-02-04 23:49:56 +11:00
Jens Axboe
9c55e01c0c [TCP]: Splice receive support.
Support for network splice receive.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 14:53:31 -08:00
Paul Moore
02f1c89d6e [NET]: Clone the sk_buff 'iif' field in __skb_clone()
Both NetLabel and SELinux (other LSMs may grow to use it as well) rely
on the 'iif' field to determine the receiving network interface of
inbound packets.  Unfortunately, at present this field is not
preserved across a skb clone operation which can lead to garbage
values if the cloned skb is sent back through the network stack.  This
patch corrects this problem by properly copying the 'iif' field in
__skb_clone() and removing the 'iif' field assignment from
skb_act_clone() since it is no longer needed.

Also, while we are here, put the assignments in the same order as the
offsets to reduce cacheline bounces.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-08 23:30:17 -08:00
Herbert Xu
2d4baff8da [SKBUFF]: Free old skb properly in skb_morph
The skb_morph function only freed the data part of the dst skb, but leaked
the auxiliary data such as the netfilter fields.  This patch fixes this by
moving the relevant parts from __kfree_skb to skb_release_all and calling
it in skb_morph.

It also makes kfree_skbmem static since it's no longer called anywhere else
and it now no longer does skb_release_data.

Thanks to Yasuyuki KOZAKAI for finding this problem and posting a patch for
it.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2007-11-26 23:11:19 +08:00
Jens Axboe
c46f2334c8 [SG] Get rid of __sg_mark_end()
sg_mark_end() overwrites the page_link information, but all users want
__sg_mark_end() behaviour where we just set the end bit. That is the most
natural way to use the sg list, since you'll fill it in and then mark the
end point.

So change sg_mark_end() to only set the termination bit. Add a sg_magic
debug check as well, and clear a chain pointer if it is set.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-11-02 08:47:06 +01:00
David S. Miller
51c739d1f4 [NET]: Fix incorrect sg_mark_end() calls.
This fixes scatterlist corruptions added by

	commit 68e3f5dd4d
	[CRYPTO] users: Fix up scatterlist conversion errors

The issue is that the code calls sg_mark_end() which clobbers the
sg_page() pointer of the final scatterlist entry.

The first part fo the fix makes skb_to_sgvec() do __sg_mark_end().

After considering all skb_to_sgvec() call sites the most correct
solution is to call __sg_mark_end() in skb_to_sgvec() since that is
what all of the callers would end up doing anyways.

I suspect this might have fixed some problems in virtio_net which is
the sole non-crypto user of skb_to_sgvec().

Other similar sg_mark_end() cases were converted over to
__sg_mark_end() as well.

Arguably sg_mark_end() is a poorly named function because it doesn't
just "mark", it clears out the page pointer as a side effect, which is
what led to these bugs in the first place.

The one remaining plain sg_mark_end() call is in scsi_alloc_sgtable()
and arguably it could be converted to __sg_mark_end() if only so that
we can delete this confusing interface from linux/scatterlist.h

Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-30 21:29:29 -07:00
Jamal Hadi Salim
a057ae3c10 [NET_CLS_ACT]: Use skb_act_clone
clean skb_clone of any signs of CONFIG_NET_CLS_ACT and
have mirred us skb_act_clone()

Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-26 02:47:54 -07:00
Jens Axboe
642f149031 SG: Change sg_set_page() to take length and offset argument
Most drivers need to set length and offset as well, so may as well fold
those three lines into one.

Add sg_assign_page() for those two locations that only needed to set
the page, where the offset/length is set outside of the function context.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-10-24 11:20:47 +02:00
Jens Axboe
fa05f1286b Update net/ to use sg helpers
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-10-22 21:19:56 +02:00
Herbert Xu
172a863f2b [NET]: Fix csum_start update in pskb_expand_head
I got confused by the dual nature of the off variable in the
function pskb_expand_head.  The csum_start offset should use
nhead instead of off which can change depending on whether we
are using offsets or pointers.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-15 12:26:33 -07:00
Herbert Xu
e0053ec07e [SKBUFF]: Add skb_morph
This patch creates a new function skb_morph that's just like skb_clone
except that it lets user provide the spare skb that will be overwritten
by the one that's to be cloned.

This will be used by IP fragment reassembly so that we get back the same
skb that went in last (rather than the head skb that we get now which
requires us to carry around double pointers all over the place).

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-15 12:26:24 -07:00
Herbert Xu
dec18810c5 [SKBUFF]: Merge common code between copy_skb_header and skb_clone
This patch creates a new function __copy_skb_header to merge the common
code between copy_skb_header and skb_clone.  Having two functions which
are largely the same is a source of wasted labour as well as confusion.

In fact the tc_verd stuff is almost certainly a bug since it's treated
differently in skb_clone compared to the callers of copy_skb_header
(skb_copy/pskb_copy/skb_copy_expand).

I've kept that difference in tact with a comment added asking for
clarification.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-15 12:26:24 -07:00
Herbert Xu
52886051ff [SKBUFF]: Fix up csum_start when head room changes
Thanks for noticing the bug where csum_start is not updated
when the head room changes.

This patch fixes that.  It also moves the csum/ip_summed
copying into copy_skb_header so that skb_copy_expand gets
it too.  I've checked its callers and no one should be upset
by this.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:51:24 -07:00
Paul Mundt
20c2df83d2 mm: Remove slab destructors from kmem_cache_create().
Slab destructors were no longer supported after Christoph's
c59def9f22 change. They've been
BUGs for both slab and slub, and slob never supported them
either.

This rips out support for the dtor pointer from kmem_cache_create()
completely and fixes up every single callsite in the kernel (there were
about 224, not including the slab allocator definitions themselves,
or the documentation references).

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2007-07-20 10:11:58 +09:00
Jozsef Kadlecsik
ba9dda3ab5 [NETFILTER]: x_tables: add TRACE target
The TRACE target can be used to follow IP and IPv6 packets through
the ruleset.

Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Patrick NcHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-07-10 22:17:14 -07:00
Peter P Waskiewicz Jr
f25f4e4480 [CORE] Stack changes to add multiqueue hardware support API
Add the multiqueue hardware device support API to the core network
stack.  Allow drivers to allocate multiple queues and manage them at
the netdev level if they choose to do so.

Added a new field to sk_buff, namely queue_mapping, for drivers to
know which tx_ring to select based on OS classification of the flow.

Signed-off-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-07-10 22:16:21 -07:00
Patrick McHardy
334a8132d9 [SKBUFF]: Keep track of writable header len of headerless clones
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: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-07-10 22:15:37 -07:00
Johannes Berg
2cd052e443 [NET] skbuff: remove export of static symbol
skb_clone_fraglist is static so it shouldn't be exported.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-07-05 17:40:19 -07:00
Olaf Kirch
5b5a60da28 [NET]: Make skb_seq_read unmap the last fragment
Having walked through the entire skbuff, skb_seq_read would leave the
last fragment mapped.  As a consequence, the unwary caller would leak
kmaps, and proceed with preempt_count off by one. The only (kind of
non-intuitive) workaround is to use skb_seq_read_abort.

This patch makes sure skb_seq_read always unmaps frag_data after
having cycled through the skb's paged part.

Signed-off-by: Olaf Kirch <olaf.kirch@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-06-23 23:11:52 -07:00
Patrick McHardy
dbbeb2f991 [SKBUFF]: Fix incorrect config #ifdef around skb_copy_secmark
secmark doesn't depend on CONFIG_NET_SCHED.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-06-23 22:58:34 -07:00
Mikael Pettersson
b6ccc67d8e [NET]: Fix net/core/skbuff.c gcc-3.2.3 compilation error
Compiling 2.6.22-rc1 with gcc-3.2.3 for i486 fails with:

  gcc -m32 -Wp,-MD,net/core/.skbuff.o.d  -nostdinc -isystem /home/mikpe/pkgs/linux-x86/gnu/lib/gcc-lib/i486-pc-linux-gnu/3.2.3/include -D__KERNEL__ -Iinclude  -include include/linux/autoconf.h -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs -fno-strict-aliasing -fno-common -O2 -pipe -msoft-float -mregparm=3 -freg-struct-return -mpreferred-stack-boundary=4  -march=i486 -ffreestanding -maccumulate-outgoing-args -DCONFIG_AS_CFI=1  -Iinclude/asm-i386/mach-default -fomit-frame-pointer       -D"KBUILD_STR(s)=#s" -D"KBUILD_BASENAME=KBUILD_STR(skbuff)"  -D"KBUILD_MODNAME=KBUILD_STR(skbuff)" -c -o net/core/skbuff.o net/core/skbuff.c
net/core/skbuff.c:648:1: directives may not be used inside a macro argument
net/core/skbuff.c:647:39: unterminated argument list invoking macro "memcpy"
net/core/skbuff.c: In function `pskb_expand_head':
net/core/skbuff.c:651: `memcpy' undeclared (first use in this function)
net/core/skbuff.c:651: (Each undeclared identifier is reported only once
net/core/skbuff.c:651: for each function it appears in.)
net/core/skbuff.c:651: syntax error before "skb"
make[2]: *** [net/core/skbuff.o] Error 1
make[1]: *** [net/core] Error 2
make: *** [net] Error 2

The patch below implements a simple workaround which is to
clone the offending memcpy() call and specialise it for the
two different scenarios.

Other workarounds are of course possible: e.g. bind the varying
parameter in a local variable, or use a macro or inline function
to perform the varying computation.

Signed-off-by: Mikael Pettersson <mikpe@it.uu.se>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-05-19 13:55:25 -07:00
David S. Miller
1a028e5072 [NET]: Revert sk_buff walker cleanups.
This reverts eefa390628

The simplification made in that change works with the assumption that
the 'offset' parameter to these functions is always positive or zero,
which is not true.  It can be and often is negative in order to access
SKB header values in front of skb->data.

Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-27 15:21:23 -07:00