no callers other than itself.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

... making both non-draining.  That means that tcp_recvmsg() becomes
non-draining.  And _that_ would break iscsit_do_rx_data() unless we
	a) make sure tcp_recvmsg() is uniformly non-draining (it is)
	b) make sure it copes with arbitrary (including shifted)
iov_iter (it does, all it uses is iov_iter primitives)
	c) make iscsit_do_rx_data() initialize ->msg_iter only once.

Fortunately, (c) is doable with minimal work and we are rid of one
the two places where kernel send/recvmsg users would be unhappy with
non-draining behaviour.

Actually, that makes all but one of ->recvmsg() instances iov_iter-clean.
The exception is skcipher_recvmsg() and it also isn't hard to convert
to primitives (iov_iter_get_pages() is needed there).  That'll wait
a bit - there's some interplay with ->sendmsg() path for that one.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Note that the code _using_ ->msg_iter at that point will be very
unhappy with anything other than unshifted iovec-backed iov_iter.
We still need to convert users to proper primitives.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Since commit f8864972 ("ipv4: fix dst race in sk_dst_get()")
DST_NOCACHE dst_entries get freed by RCU. So there is no need to get a
reference on them when we are in rcu protected sections.

Cc: Eric Dumazet <edumazet@google.com>
Cc: Julian Anastasov <ja@ssi.bg>
Signed-off-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Reviewed-by: NJulian Anastasov <ja@ssi.bg>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit ce1a4ea3 ("net: avoid one atomic operation in skb_clone()")
took the wrong way to save one atomic operation.

It is actually possible to avoid two atomic operations, if we
do not change skb->fclone values, and only rely on clone_ref
content to signal if the clone is available or not.

skb_clone() can simply use the fast clone if clone_ref is 1.

kfree_skbmem() can avoid the atomic_dec_and_test() if clone_ref is 1.

Note that because we usually free the clone before the original skb,
this particular attempt is only done for the original skb to have better
branch prediction.

SKB_FCLONE_FREE is removed.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Chris Mason <clm@fb.com>
Cc: Sabrina Dubroca <sd@queasysnail.net>
Cc: Vijay Subramanian <subramanian.vijay@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds two new helper functions skb_put_padto and eth_skb_pad.
These functions deviate from the standard skb_pad or skb_padto in that they
will also update the length and tail pointers so that they reflect the
padding added to the frame.

The eth_skb_pad helper is meant to be used with Ethernet devices to update
either Rx or Tx frames so that they report the correct size.  The
skb_put_padto helper is meant to be used primarily in the transmit path for
network devices that need frames to be padded up to some minimum size and
don't wish to simply update the length somewhere external to the frame.

The motivation behind this is that there are a number of implementations
throughout the network device drivers that are all doing the same thing,
but each a little bit differently and as a result several implementations
contain bugs such as updating the length without updating the tail offset
and other similar issues.
Signed-off-by: NAlexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

... and kill skb_copy_datagram_iovec()
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

no users left
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

So it can be used from out of openvswitch code.
Did couple of cosmetic changes on the way, namely variable naming and
adding support for 8021AD proto.
Signed-off-by: NJiri Pirko <jiri@resnulli.us>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

note that skb_make_writable already exists in net/netfilter/core.c
but does something slightly different.
Suggested-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NJiri Pirko <jiri@resnulli.us>
Acked-by: NPravin B Shelar <pshelar@nicira.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Remove the two functions which are now dead code.
Signed-off-by: NAlexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch implements __dev_alloc_pages and __dev_alloc_page.  These are
meant to replace the __skb_alloc_pages and __skb_alloc_page functions.  The
reason for doing this is that it occurred to me that __skb_alloc_page is
supposed to be passed an sk_buff pointer, but it is NULL in all cases where
it is used.  Worse is that in the case of ixgbe it is passed NULL via the
sk_buff pointer in the rx_buffer info structure which means the compiler is
not correctly stripping it out.

The naming for these functions is based on dev_alloc_skb and __dev_alloc_skb.
There was originally a netdev_alloc_page, however that was passed a
net_device pointer and this function is not so I thought it best to follow
that naming scheme since that is the same difference between dev_alloc_skb
and netdev_alloc_skb.

In the case of anything greater than order 0 it is assumed that we want a
compound page so __GFP_COMP is set for all allocations as we expect a
compound page when assigning a page frag.

The other change in this patch is to exploit the behaviors of the page
allocator in how it handles flags.  So for example we can always set
__GFP_COMP and __GFP_MEMALLOC since they are ignored if they are not
applicable or are overridden by another flag.
Signed-off-by: NAlexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Now that both macvtap and tun are using skb_copy_datagram_iter, we
can kill the abomination that is skb_copy_datagram_const_iovec.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds skb_copy_datagram_iter, which is identical to
skb_copy_datagram_iovec except that it operates on iov_iter
instead of iovec.

Eventually all users of skb_copy_datagram_iovec should switch
over to iov_iter and then we can remove skb_copy_datagram_iovec.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Device can export MPLS GSO support in dev->mpls_features same way
it export vlan features in dev->vlan_features. So it is safe to
remove NETIF_F_GSO_MPLS redundant flag.
Signed-off-by: NPravin B Shelar <pshelar@nicira.com>

This encapsulates all of the skb_copy_datagram_iovec() callers
with call argument signature "skb, offset, msghdr->msg_iov, length".

When we move to iov_iters in the networking, the iov_iter object will
sit in the msghdr.

Having a helper like this means there will be less places to touch
during that transformation.

Based upon descriptions and patch from Al Viro.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add a new GSO type, SKB_GSO_TUNNEL_REMCSUM, which indicates remote
checksum offload being done (in this case inner checksum must not
be offloaded to the NIC).

Added logic in __skb_udp_tunnel_segment to handle remote checksum
offload case.
Signed-off-by: NTom Herbert <therbert@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Yaogong replaces TCP out of order receive queue by an RB tree.

As netem already does a private skb->{next/prev/tstamp} union
with a 'struct rb_node', lets do this in a cleaner way.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Yaogong Wang <wygivan@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Some drivers are unable to perform TX completions in a bound time.
They instead call skb_orphan()

Problem is skb_fclone_busy() has to detect this case, otherwise
we block TCP retransmits and can freeze unlucky tcp sessions on
mostly idle hosts.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Fixes: 1f3279ae ("tcp: avoid retransmits of TCP packets hanging in host queues")
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix kernel-doc warning in <linux/skbuff.h> by making both headers_start
and headers_end private fields.

Warning(..//include/linux/skbuff.h:654): No description found for parameter 'headers_end[0]'
Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If the skb is not dropped afterwards we should run consume_skb instead
kfree_skb. Inside of function skb_unshare we do always a kfree_skb,
doesn't depend if skb_copy failed or was successful.

This patch switch this behaviour like skb_share_check, if allocation of
sk_buff failed we use kfree_skb otherwise consume_skb.
Signed-off-by: NAlexander Aring <alex.aring@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In commit 7bced397,
dma_cookie was removed from struct skbuff.
But the description of dma_cookie still exist.
So the "make xmldocs" output following warning.

Warning(.//include/linux/skbuff.h:609): Excess struct/union
/enum/typedef member 'dma_cookie' description in 'sk_buff'

Remove description of dma_cookie fix the symptom.
Signed-off-by: NMasanari Iida <standby24x7@gmail.com>
Acked-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

SKB_FCLONE_UNAVAILABLE has overloaded meaning depending on type of skb.
1: If skb is allocated from head_cache, it indicates fclone is not available.
2: If skb is a companion fclone skb (allocated from fclone_cache), it indicates
it is available to be used.

To avoid confusion for case 2 above, this patch  replaces
SKB_FCLONE_UNAVAILABLE with SKB_FCLONE_FREE where appropriate. For fclone
companion skbs, this indicates it is free for use.

SKB_FCLONE_UNAVAILABLE will now simply indicate skb is from head_cache and
cannot / will not have a companion fclone.
Signed-off-by: NVijay Subramanian <subramanian.vijay@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

skb_udp_segment is the function called from udp4_ufo_fragment to
segment a UDP tunnel packet. This function currently assumes
segmentation is transparent Ethernet bridging (i.e. VXLAN
encapsulation). This patch generalizes the function to
operate on either Ethertype or IP protocol.

The inner_protocol field must be set to the protocol of the inner
header. This can now be either an Ethertype or an IP protocol
(in a union). A new flag in the skbuff indicates which type is
effective. skb_set_inner_protocol and skb_set_inner_ipproto
helper functions were added to set the inner_protocol. These
functions are called from the point where the tunnel encapsulation
is occuring.

When skb_udp_tunnel_segment is called, the function to segment the
inner packet is selected based on the inner IP or Ethertype. In the
case of an IP protocol encapsulation, the function is derived from
inet[6]_offloads. In the case of Ethertype, skb->protocol is
set to the inner_protocol and skb_mac_gso_segment is called. (GRE
currently does this, but it might be possible to lookup the protocol
in offload_base and call the appropriate segmenation function
directly).
Signed-off-by: NTom Herbert <therbert@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Lets use a proper structure to clearly document and implement
skb fast clones.

Then, we might experiment more easily alternative layouts.

This patch adds a new skb_fclone_busy() helper, used by tcp and xfrm,
to stop leaking of implementation details.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

With proliferation of bit fields in sk_buff, __copy_skb_header() became
quite expensive, showing as the most expensive function in a GSO
workload.

__copy_skb_header() performance is also critical for non GSO TCP
operations, as it is used from skb_clone()

This patch carefully moves all the fields that were not copied in a
separate zone : cloned, nohdr, fclone, peeked, head_frag, xmit_more

Then I moved all other fields and all other copied fields in a section
delimited by headers_start[0]/headers_end[0] section so that we
can use a single memcpy() call, inlined by compiler using long
word load/stores.

I also tried to make all copies in the natural orders of sk_buff,
to help hardware prefetching.

I made sure sk_buff size did not change.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Per commit "77873803 net_dma: mark broken" net_dma is no longer used
and there is no plan to fix it.

This is the mechanical removal of bits in CONFIG_NET_DMA ifdef guards.
Reverting the remainder of the net_dma induced changes is deferred to
subsequent patches.

Marked for stable due to Roman's report of a memory leak in
dma_pin_iovec_pages():

    https://lkml.org/lkml/2014/9/3/177

Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Vinod Koul <vinod.koul@intel.com>
Cc: David Whipple <whipple@securedatainnovations.ch>
Cc: Alexander Duyck <alexander.h.duyck@intel.com>
Cc: <stable@vger.kernel.org>
Reported-by: NRoman Gushchin <klamm@yandex-team.ru>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

While profiling TCP stack, I noticed one useless atomic operation
in tcp_sendmsg(), caused by skb_header_release().

It turns out all current skb_header_release() users have a fresh skb,
that no other user can see, so we can avoid one atomic operation.

Introduce __skb_header_release() to clearly document this.

This gave me a 1.5 % improvement on TCP_RR workload.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Jesper reported that br_netfilter always registers the hooks since
this is part of the bridge core. This harms performance for people that
don't need this.

This patch modularizes br_netfilter so it can be rmmod'ed, thus,
the hooks can be unregistered. I think the bridge netfilter should have
been a separated module since the beginning, Patrick agreed on that.

Note that this is breaking compatibility for users that expect that
bridge netfilter is going to be available after explicitly 'modprobe
bridge' or via automatic load through brctl.

However, the damage can be easily undone by modprobing br_netfilter.
The bridge core also spots a message to provide a clue to people that
didn't notice that this has been deprecated.

On top of that, the plan is that nftables will not rely on this software
layer, but integrate the connection tracking into the bridge layer to
enable stateful filtering and NAT, which is was bridge netfilter users
seem to require.

This patch still keeps the fake_dst_ops in the bridge core, since this
is required by when the bridge port is initialized. So we can safely
modprobe/rmmod br_netfilter anytime.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
Acked-by: NFlorian Westphal <fw@strlen.de>

Extract from sock_alloc_send_pskb() code building skb with frags,
so that we can reuse this in other contexts.

Intent is to use it from tcp_send_rcvq(), tcp_collapse(), ...

We also want to replace some skb_linearize() calls to a more reliable
strategy in pathological cases where we need to reduce number of frags.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently we have 2 pkt_type_offset functions doing the same thing and
spread across the architecture files. Remove those and replace them
with a PKT_TYPE_OFFSET macro helper which gets the constant value from a
zero sized sk_buff member right in front of the bitfield with offsetof.
This new offset marker does not change size of struct sk_buff.

Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Daniel Borkmann <dborkman@redhat.com>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: NDenis Kirjanov <kda@linux-powerpc.org>
Signed-off-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: NAlexei Starovoitov <ast@plumgrid.com>
Acked-by: NDaniel Borkmann <dborkman@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch updates some of the flow_dissector api so that it can be used to
parse the length of ethernet buffers stored in fragments.  Most of the
changes needed were to __skb_get_poff as it needed to be updated to support
sending a linear buffer instead of a skb.

I have split __skb_get_poff into two functions, the first is skb_get_poff
and it retains the functionality of the original __skb_get_poff.  The other
function is __skb_get_poff which now works much like __skb_flow_dissect in
relation to skb_flow_dissect in that it provides the same functionality but
works with just a data buffer and hlen instead of needing an skb.
Signed-off-by: NAlexander Duyck <alexander.h.duyck@intel.com>
Acked-by: NAlexei Starovoitov <ast@plumgrid.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The phy timestamping takes a different path than the regular timestamping
does in that it will create a clone first so that the packets needing to be
timestamped can be placed in a queue, or the context block could be used.

In order to support these use cases I am pulling the core of the code out
so it can be used in other drivers beyond just phy devices.

In addition I have added a destructor named sock_efree which is meant to
provide a simple way for dropping the reference to skb exceptions that
aren't part of either the receive or send windows for the socket, and I
have removed some duplication in spots where this destructor could be used
in place of sock_edemux.
Signed-off-by: NAlexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

For normal path, added skb_checksum_try_convert which is called
to attempt to convert CHECKSUM_UNNECESSARY to CHECKSUM_COMPLETE. The
primary condition to allow this is that ip_summed is CHECKSUM_NONE
and csum_valid is true, which will be the state after consuming
a CHECKSUM_UNNECESSARY.

For GRO path, added skb_gro_checksum_try_convert which is the GRO
analogue of skb_checksum_try_convert. The primary condition to allow
this is that NAPI_GRO_CB(skb)->csum_cnt == 0 and
NAPI_GRO_CB(skb)->csum_valid is set. This implies that we have consumed
all available CHECKSUM_UNNECESSARY checksums in the GRO path.
Signed-off-by: NTom Herbert <therbert@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This flag indicates that an invalid checksum was detected in the
packet. __skb_mark_checksum_bad helper function was added to set this.

Checksums can be marked bad from a driver or the GRO path (the latter
is implemented in this patch). csum_bad is checked in
__skb_checksum_validate_complete (i.e. calling that when ip_summed ==
CHECKSUM_NONE).

csum_bad works in conjunction with ip_summed value. In the case that
ip_summed is CHECKSUM_NONE and csum_bad is set, this implies that the
first (or next) checksum encountered in the packet is bad. When
ip_summed is CHECKSUM_UNNECESSARY, the first checksum after the last
one validated is bad. For example, if ip_summed == CHECKSUM_UNNECESSARY,
csum_level == 1, and csum_bad is set-- then the third checksum in the
packet is bad. In the normal path, the packet will be dropped when
processing the protocol layer of the bad checksum:
__skb_decr_checksum_unnecessary called twice for the good checksums
changing ip_summed to CHECKSUM_NONE so that
__skb_checksum_validate_complete is called to validate the third
checksum and that will fail since csum_bad is set.
Signed-off-by: NTom Herbert <therbert@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch:
 - Clarifies the specific requirements of devices returning
   CHECKSUM_UNNECESSARY (comments in skbuff.h).
 - Adds csum_level field to skbuff. This is used to express how
   many checksums are covered by CHECKSUM_UNNECESSARY (stores n - 1).
   This replaces the overloading of skb->encapsulation, that field is
   is now only used to indicate inner headers are valid.
 - Change __skb_checksum_validate_needed to "consume" each checksum
   as indicated by csum_level as layers of the the packet are parsed.
 - Remove skb_pop_rcv_encapsulation, no longer needed in the new
   csum_level model.
Signed-off-by: NTom Herbert <therbert@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>