This patch adds the GSO implementation for IPv4 TCP.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Having separate fields in sk_buff for TSO/UFO (tso_size/ufo_size) is not
going to scale if we add any more segmentation methods (e.g., DCCP).  So
let's merge them.

They were used to tell the protocol of a packet.  This function has been
subsumed by the new gso_type field.  This is essentially a set of netdev
feature bits (shifted by 16 bits) that are required to process a specific
skb.  As such it's easy to tell whether a given device can process a GSO
skb: you just have to and the gso_type field and the netdev's features
field.

I've made gso_type a conjunction.  The idea is that you have a base type
(e.g., SKB_GSO_TCPV4) that can be modified further to support new features.
For example, if we add a hardware TSO type that supports ECN, they would
declare NETIF_F_TSO | NETIF_F_TSO_ECN.  All TSO packets with CWR set would
have a gso_type of SKB_GSO_TCPV4 | SKB_GSO_TCPV4_ECN while all other TSO
packets would be SKB_GSO_TCPV4.  This means that only the CWR packets need
to be emulated in software.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

First of all it is unnecessary to allocate a new skb in skb_pad since
the existing one is not shared.  More importantly, our hard_start_xmit
interface does not allow a new skb to be allocated since that breaks
requeueing.

This patch uses pskb_expand_head to expand the existing skb and linearize
it if needed.  Actually, someone should sift through every instance of
skb_pad on a non-linear skb as they do not fit the reasons why this was
originally created.

Incidentally, this fixes a minor bug when the skb is cloned (tcpdump,
TCP, etc.).  As it is skb_pad will simply write over a cloned skb.  Because
of the position of the write it is unlikely to cause problems but still
it's best if we don't do it.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It's better to warn and fail rather than rarely triggering BUG on paths
that incorrectly call skb_trim/__skb_trim on a non-linear skb.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The linearisation operation doesn't need to be super-optimised.  So we can
replace __skb_linearize with __pskb_pull_tail which does the same thing but
is more general.

Also, most users of skb_linearize end up testing whether the skb is linear
or not so it helps to make skb_linearize do just that.

Some callers of skb_linearize also use it to copy cloned data, so it's
useful to have a new function skb_linearize_cow to copy the data if it's
either non-linear or cloned.

Last but not least, I've removed the gfp argument since nobody uses it
anymore.  If it's ever needed we can easily add it back.

Misc bugs fixed by this patch:

* via-velocity error handling (also, no SG => no frags)
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add a secmark field to the skbuff structure, to allow security subsystems to
place security markings on network packets.  This is similar to the nfmark
field, except is intended for implementing security policy, rather than than
networking policy.

This patch was already acked in principle by Dave Miller.
Signed-off-by: NJames Morris <jmorris@namei.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Adds an async_wait_queue and some additional fields to tcp_sock, and a
dma_cookie_t to sk_buff.
Signed-off-by: NChris Leech <christopher.leech@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

Add some sanity checking.  truesize should be at least sizeof(struct
sk_buff) plus the current packet length.  If not, then truesize is
seriously mangled and deserves a kernel log message.

Currently we'll do the check for release of stream socket buffers.

But we can add checks to more spots over time.

Incorporating ideas from Herbert Xu.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Previously we added NET_IP_ALIGN so an architecture can override the
padding done to align headers. The next step is to allow the skb
headroom to be overridden.

We currently always reserve 16 bytes to grow into, meaning all DMAs
start 16 bytes into a cacheline. On ppc64 we really want DMA writes to
start on a cacheline boundary, so we increase that headroom to one
cacheline.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We're now starting to have quite a number of places that do skb_pull
followed immediately by an skb_postpull_rcsum.  We can merge these two
operations into one function with skb_pull_rcsum.  This makes sense
since most pull operations on receive skb's need to update the
checksum.

I've decided to make this out-of-line since it is fairly big and the
fast path where hardware checksums are enabled need to call
csum_partial anyway.

Since this is a brand new function we get to add an extra check on the
len argument.  As it is most callers of skb_pull ignore its return
value which essentially means that there is no check on the len
argument.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

o Uninline kfree_skb, which saves some 15k of object code on my notebook.

o Allow kfree_skb to be called with a NULL argument.

  Subsequent patches can remove conditional from drivers and further
  reduce source and object size.
Signed-off-by: NJrn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The bridge netfilter code simulates the NF_IP_PRE_ROUTING hook and skips
the real hook by registering with high priority and returning NF_STOP if
skb->nf_bridge is present and the BRNF_NF_BRIDGE_PREROUTING flag is not
set. The flag is only set during the simulated hook.

Because skb->nf_bridge is only freed when the packet is destroyed, the
packet will not only skip the first invocation of NF_IP_PRE_ROUTING, but
in the case of tunnel devices on top of the bridge also all further ones.
Forwarded packets from a bridge encapsulated by a tunnel device and sent
as locally outgoing packet will also still have the incorrect bridge
information from the input path attached.

We already have nf_reset calls on all RX/TX paths of tunnel devices,
so simply reset the nf_bridge field there too. As an added bonus,
the bridge information for locally delivered packets is now also freed
when the packet is queued to a socket.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Move skb->nf_mark next to skb->tc_index to remove a 4 byte hole between
skb->nfmark and skb->nfct and another one between skb->users and skb->head
when CONFIG_NETFILTER, CONFIG_NET_SCHED and CONFIG_NET_CLS_ACT are enabled.
For all other combinations the size stays the same.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Some subsystems, such as PPP, can send negative values
here.  It just happened to work correctly on 32-bit with
an unsigned value, but on 64-bit this explodes.

Figured out by Paul Mackerras based upon several PPP crash
reports.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

ip_route_me_harder doesn't use the port numbers of the xfrm lookup and
uses ip_route_input for non-local addresses which doesn't do a xfrm
lookup, ip6_route_me_harder doesn't do a xfrm lookup at all.

Use xfrm_decode_session and do the lookup manually, make sure both
only do the lookup if the packet hasn't been transformed already.

Makeing sure the lookup only happens once needs a new field in the
IP6CB, which exceeds the size of skb->cb. The size of skb->cb is
increased to 48b. Apparently the IPv6 mobile extensions need some
more room anyway.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

From: Benjamin LaHaise <bcrl@kvack.org>

In __alloc_skb(), the use of skb_shinfo() which casts a u8 * to the 
shared info structure results in gcc being forced to do a reload of the 
pointer since it has no information on possible aliasing.  Fix this by 
using a pointer to refer to skb_shared_info.

By initializing skb_shared_info sequentially, the write combining buffers 
can reduce the number of memory transactions to a single write.  Reorder 
the initialization in __alloc_skb() to match the structure definition.  
There is also an alignment issue on 64 bit systems with skb_shared_info 
by converting nr_frags to a short everything packs up nicely.

Also, pass the slab cache pointer according to the fclone flag instead 
of using two almost identical function calls.

This raises bw_unix performance up to a peak of 707KB/s when combined 
with the spinlock patch.  It should help other networking protocols, too.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

sock_init can be done as a core_initcall instead of calling
it directly in init/main.c

Also I removed an out of date #ifdef.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When a packet is obtained from skb_recv_datagram with MSG_PEEK enabled
it is left on the socket receive queue.  This means that when we detect
a checksum error we have to be careful when trying to free the packet
as someone could have dequeued it in the time being.

Currently this delicate logic is duplicated three times between UDPv4,
UDPv6 and RAWv6.  This patch moves them into a one place and simplifies
the code somewhat.

This is based on a suggestion by Eric Dumazet.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix kernel-doc warnings in network files.
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.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>

Here is the patch that introduces the generic skb_checksum_complete
which also checks for hardware RX checksum faults.  If that happens,
it'll call netdev_rx_csum_fault which currently prints out a stack
trace with the device name.  In future it can turn off RX checksum.

I've converted every spot under net/ that does RX checksum checks to
use skb_checksum_complete or __skb_checksum_complete with the
exceptions of:

* Those places where checksums are done bit by bit.  These will call
netdev_rx_csum_fault directly.

* The following have not been completely checked/converted:

ipmr
ip_vs
netfilter
dccp

This patch is based on patches and suggestions from Stephen Hemminger
and David S. Miller.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The existing connection tracking subsystem in netfilter can only
handle ipv4.  There were basically two choices present to add
connection tracking support for ipv6.  We could either duplicate all
of the ipv4 connection tracking code into an ipv6 counterpart, or (the
choice taken by these patches) we could design a generic layer that
could handle both ipv4 and ipv6 and thus requiring only one sub-protocol
(TCP, UDP, etc.) connection tracking helper module to be written.

In fact nf_conntrack is capable of working with any layer 3
protocol.

The existing ipv4 specific conntrack code could also not deal
with the pecularities of doing connection tracking on ipv6,
which is also cured here.  For example, these issues include:

1) ICMPv6 handling, which is used for neighbour discovery in
   ipv6 thus some messages such as these should not participate
   in connection tracking since effectively they are like ARP
   messages

2) fragmentation must be handled differently in ipv6, because
   the simplistic "defrag, connection track and NAT, refrag"
   (which the existing ipv4 connection tracking does) approach simply
   isn't feasible in ipv6

3) ipv6 extension header parsing must occur at the correct spots
   before and after connection tracking decisions, and there were
   no provisions for this in the existing connection tracking
   design

4) ipv6 has no need for stateful NAT

The ipv4 specific conntrack layer is kept around, until all of
the ipv4 specific conntrack helpers are ported over to nf_conntrack
and it is feature complete.  Once that occurs, the old conntrack
stuff will get placed into the feature-removal-schedule and we will
fully kill it off 6 months later.
Signed-off-by: NYasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp>
Signed-off-by: NHarald Welte <laforge@netfilter.org>
Signed-off-by: NArnaldo Carvalho de Melo <acme@mandriva.com>

Change netem to support packets getting reordered because of variations in
delay. Introduce a special case version of FIFO that queues packets in order
based on the netem delay.

Since netem is classful, those users that don't want jitter based reordering
can just insert a pfifo instead of the default.

This required changes to generic skbuff code to allow finer grain manipulation
of sk_buff_head.  Insertion into the middle and reverse walk.
Signed-off-by: NStephen Hemminger <shemminger@osdl.org>
Signed-off-by: NArnaldo Carvalho de Melo <acme@mandriva.com>

Attached is kernel patch for UDP Fragmentation Offload (UFO) feature.

1. This patch incorporate the review comments by Jeff Garzik.
2. Renamed USO as UFO (UDP Fragmentation Offload)
3. udp sendfile support with UFO

This patches uses scatter-gather feature of skb to generate large UDP
datagram. Below is a "how-to" on changes required in network device
driver to use the UFO interface.

UDP Fragmentation Offload (UFO) Interface:
-------------------------------------------
UFO is a feature wherein the Linux kernel network stack will offload the
IP fragmentation functionality of large UDP datagram to hardware. This
will reduce the overhead of stack in fragmenting the large UDP datagram to
MTU sized packets

1) Drivers indicate their capability of UFO using
dev->features |= NETIF_F_UFO | NETIF_F_HW_CSUM | NETIF_F_SG

NETIF_F_HW_CSUM is required for UFO over ipv6.

2) UFO packet will be submitted for transmission using driver xmit routine.
UFO packet will have a non-zero value for

"skb_shinfo(skb)->ufo_size"

skb_shinfo(skb)->ufo_size will indicate the length of data part in each IP
fragment going out of the adapter after IP fragmentation by hardware.

skb->data will contain MAC/IP/UDP header and skb_shinfo(skb)->frags[]
contains the data payload. The skb->ip_summed will be set to CHECKSUM_HW
indicating that hardware has to do checksum calculation. Hardware should
compute the UDP checksum of complete datagram and also ip header checksum of
each fragmented IP packet.

For IPV6 the UFO provides the fragment identification-id in
skb_shinfo(skb)->ip6_frag_id. The adapter should use this ID for generating
IPv6 fragments.
Signed-off-by: NAnanda Raju <ananda.raju@neterion.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (forwarded)
Signed-off-by: NArnaldo Carvalho de Melo <acme@mandriva.com>

Add kernel-doc to skbuff.h, skbuff.c to eliminate kernel-doc warnings.
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NArnaldo Carvalho de Melo <acme@mandriva.com>

 - added typedef unsigned int __nocast gfp_t;

 - replaced __nocast uses for gfp flags with gfp_t - it gives exactly
   the same warnings as far as sparse is concerned, doesn't change
   generated code (from gcc point of view we replaced unsigned int with
   typedef) and documents what's going on far better.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

I've found the problem in general.  It affects any 64-bit
architecture.  The problem occurs when you change the system time.

Suppose that when you boot your system clock is forward by a day.
This gets recorded down in skb_tv_base.  You then wind the clock back
by a day.  From that point onwards the offset will be negative which
essentially overflows the 32-bit variables they're stored in.

In fact, why don't we just store the real time stamp in those 32-bit
variables? After all, we're not going to overflow for quite a while
yet.

When we do overflow, we'll need a better solution of course.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since packets almost never contain extra garbage at the end, it is
worthwhile to optimize for that case.
Signed-off-by: NStephen Hemminger <shemminger@osdl.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The new timestamp get/set routines should have const attribute
on parameters (helps to indicate direction).
Signed-off-by: NStephen Hemminger <shemminger@osdl.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Protocols that make extensive use of SKB cloning,
for example TCP, eat at least 2 allocations per
packet sent as a result.

To cut the kmalloc() count in half, we implement
a pre-allocation scheme wherein we allocate
2 sk_buff objects in advance, then use a simple
reference count to free up the memory at the
correct time.

Based upon an initial patch by Thomas Graf and
suggestions from Herbert Xu.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Of this type, mostly:

CHECK   net/ipv6/netfilter.c
net/ipv6/netfilter.c:96:12: warning: symbol 'ipv6_netfilter_init' was not declared. Should it be static?
net/ipv6/netfilter.c:101:6: warning: symbol 'ipv6_netfilter_fini' was not declared. Should it be static?
Signed-off-by: NArnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Reduces skb size by 8 bytes on 64-bit.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Bonding just wants the device before the skb_bond()
decapsulation occurs, so simply pass that original
device into packet_type->func() as an argument.

It remains to be seen whether we can use this same
exact thing to get rid of skb->input_dev as well.
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 removes the private element from skbuff, that is only used by
HIPPI. Instead it uses skb->cb[] to hold the additional data that is
needed in the output path from hard_header to device driver.

PS: The only qdisc that might potentially corrupt this cb[] is if
netem was used over HIPPI. I will take care of that by fixing netem
to use skb->stamp. I don't expect many users of netem over HIPPI
Signed-off-by: NStephen Hemminger <shemminger@osdl.org>
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>

Remove the "list" member of struct sk_buff, as it is entirely
redundant.  All SKB list removal callers know which list the
SKB is on, so storing this in sk_buff does nothing other than
taking up some space.

Two tricky bits were SCTP, which I took care of, and two ATM
drivers which Francois Romieu <romieu@fr.zoreil.com> fixed
up.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NFrancois Romieu <romieu@fr.zoreil.com>

As discussed at netconf'05, we're trying to save every bit in sk_buff.
The patch below makes sk_buff 8 bytes smaller.  I did some basic
testing on my notebook and it seems to work.

The only real in-tree user of nfcache was IPVS, who only needs a
single bit.  Unfortunately I couldn't find some other free bit in
sk_buff to stuff that bit into, so I introduced a separate field for
them.  Maybe the IPVS guys can resolve that to further save space.

Initially I wanted to shrink pkt_type to three bits (PACKET_HOST and
alike are only 6 values defined), but unfortunately the bluetooth code
overloads pkt_type :(

The conntrack-event-api (out-of-tree) uses nfcache, but Rusty just
came up with a way how to do it without any skb fields, so it's safe
to remove it.

- remove all never-implemented 'nfcache' code
- don't have ipvs code abuse 'nfcache' field. currently get's their own
  compile-conditional skb->ipvs_property field.  IPVS maintainers can
  decide to move this bit elswhere, but nfcache needs to die.
- remove skb->nfcache field to save 4 bytes
- move skb->nfctinfo into three unused bits to save further 4 bytes
Signed-off-by: NHarald Welte <laforge@netfilter.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As discussed at netconf'05, we convert nfmark and conntrack-mark to be
32bits even on 64bit architectures.
Signed-off-by: NHarald Welte <laforge@netfilter.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>