If the allfrag feature has been set on a host route (due to an ICMPv6
Packet Too Big received indicating a MTU of less than 1280), we hit a
very slow behavior in TCP stack, because all big packets are dropped and
only a retransmit timer is able to push one MSS frame every 200 ms.

One way to handle this is to disable GSO on the socket the first time a
super packet is dropped. Adding a specific dst_allfrag() in the fast
path is probably overkill since the dst_allfrag() case almost never
happen.

Result on netperf TCP_STREAM, one flow :

Before : 60 kbit/sec
After : 1.6 Gbit/sec
Reported-by: Tore Anderson <tore@fud.no>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Tested-by: Tore Anderson <tore@fud.no>
Signed-off-by: David S. Miller <davem@davemloft.net>

Update our reference driver to use netdev_alloc_frag() API instead of
the temporary custom allocator I introduced in commit 8d4057a9
(tg3: provide frags as skb head)

This removes the memory leak we had, since we could leak one page at
device dismantle.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Matt Carlson <mcarlson@broadcom.com>
Cc: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

No need to export napi_frags_skb()
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Call consume_skb() in place of kfree_skb() were appropriate.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Mostly bool conversions, some inline removals and const additions.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

We already unconditionally dereference 'sk' via lock_sock(sk) earlier
in this function, and our caller (sock_do_ioctl()) makes takes similar
liberties.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Quoting Tore Anderson from :

If the allfrag feature has been set on a host route (due to an ICMPv6
Packet Too Big received indicating a MTU of less than 1280),
TCP SYN/ACK packets to that destination appears to get an incorrect
TCP checksum. This in turn means they are thrown away as invalid.

In the case of an IPv4 client behind a link with a MTU of less than
1260, accessing an IPv6 server through a stateless translator,
this means that the client can only download a single large file
from the server, because once it is in the server's routing cache
with the allfrag feature set, new TCP connections can no longer
be established.

</endquote>

It appears ip6_fragment() doesn't handle CHECKSUM_PARTIAL properly.

As network drivers are not prepared to fetch correct transport header, a
safe fix is to call skb_checksum_help() before fragmenting packet.
Reported-by: Tore Anderson <tore@fud.no>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Tested-by: Tore Anderson <tore@fud.no>
Signed-off-by: David S. Miller <davem@davemloft.net>

Move blocks of code around to avoid function prototypes.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Introduce and use a debug macro to test and print.
Convert printks to pr_<level>.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Just some stylings.

Use #include <linux... not #include <asm...
Convert a test and print to a printk_once.
Combine an "if (foo) { if (bar) {" to single "if (foo && bar) {"
to save an indent level.
Convert single line "if (foo) bar;" to multiple lines.
Move some braces.
Align some long lines a bit better.

Long lines and printks with KERN_ checkpatch complaints
still exist.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Use more current logging styles.

Add pr_fmt.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Neaten the comments and reflow the code without
changing anything other than whitespace.

git diff -w shows just comment neatening and a few
line removals.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Patch re-spin.
Incorporated review comments by Ben Hutchings.
Signed-off-by: Suresh Reddy <suresh.reddy@emulex.com>
Signed-off-by: Somnath Kotur <somnath.kotur@emulex.com>
Acked-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

csummode variable is always CHECKSUM_NONE in ip6_append_data()
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix two issues introduced in commit a1c7fff7
( net: netdev_alloc_skb() use build_skb() )

- Must be IRQ safe (non NAPI drivers can use it)
- Must not leak the frag if build_skb() fails to allocate sk_buff

This patch introduces netdev_alloc_frag() for drivers willing to
use build_skb() instead of __netdev_alloc_skb() variants.

Factorize code so that :
__dev_alloc_skb() is a wrapper around __netdev_alloc_skb(), and
dev_alloc_skb() a wrapper around netdev_alloc_skb()

Use __GFP_COLD flag.

Almost all network drivers now benefit from skb->head_frag
infrastructure.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

As iwlwifi use fat skbs, it should not pull too much data in skb->head,
and particularly no tcp data payload, or splice() is slower, and TCP
coalescing is disabled. Copying payload to userland also involves at
least two copies (part from header, part from fragment)

Each layer will pull its header from the fragment as needed.

(on 64bit arches, skb_tailroom(skb) at this point is 192 bytes)

With this patch applied, I have a major reduction of collapsed/pruned
TCP packets, a nice increase of TCPRcvCoalesce counter, and overall
better Internet User experience.

Small packets are still using a fragless skb, so that page can be reused
by the driver.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Johannes Berg <johannes.berg@intel.com>
Cc: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv6_opt_accepted() returns a bool, and can use const pointers

ipv6_addr_equal(), ipv6_addr_any(), ipv6_addr_loopback(),
ipv6_addr_orchid() return a bool.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

- match() method returns a boolean
- return (A && B && C && D) -> return A && B && C && D
- fix indentation
Signed-off-by: Eric Dumazet <edumazet@google.com>

ECONET is gone, thus this can be deleted as well.
Signed-off-by: David S. Miller <davem@davemloft.net>

More spring cleaning!

The ancient Econet protocol should go. Most of the bug fixes in recent
years have been fixing security vulnerabilities. The hardware hasn't
been made since the 90s, it is only interesting as an archeological curiosity.

For the truly curious, or insomniac, go read up on it.
  http://en.wikipedia.org/wiki/EconetSigned-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The use of the inw/outw functions by the cs89x0 platform driver
results in NULL pointer references on ARM platforms and
platforms that do not provide ISA-style programmed I/O accessors.

Using inw/outw also accesses the wrong address space on platforms
that have a PCI I/O space that is not identity-mapped into the
physical address space.
Signed-off-by: Jaccon Bastiaansen <jaccon.bastiaansen@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Enable dynamic debugging and remove a bunch of #ifdef/#endifs.

Add a lapb_dbg(level, fmt, ...) macro and replace the
printk(KERN_DEBUG uses.
Add pr_fmt and remove embedded prefixes.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The support for CONFIG_MCA is being removed, since the 20
year old hardware simply isn't capable of meeting today's
software demands on CPU and memory resources.

This commit removes any MCA specific net drivers, and removes
any MCA specific probe/support code from drivers that were
doing a dual ISA/MCA role.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: netdev@vger.kernel.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

Change the TX ring scheme such that the number of rings for untagged packets
and for tagged packets (per each of the vlan priorities) is the same, unlike
the current situation where for tagged traffic there's one ring per priority
and for untagged rings as the number of core.

Queue selection is done as follows:

If the mqprio qdisc is operates on the interface, such that the core networking
code invoked the device setup_tc ndo callback, a mapping of skb->priority =>
queue set is forced - for both, tagged and untagged traffic.

Else, the egress map skb->priority =>  User priority is used for tagged traffic, and
all untagged traffic is sent through tx rings of UP 0.

The patch follows the convergence of discussing that issue with John Fastabend
over this thread http://comments.gmane.org/gmane.linux.network/229877

Cc: John Fastabend <john.r.fastabend@intel.com>
Cc: Liran Liss <liranl@mellanox.com>
Signed-off-by: Amir Vadai <amirv@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When I first wrote drop monitor I wrote it to just build monolithically.  There
is no reason it can't be built modularly as well, so lets give it that
flexibiity.

I've tested this by building it as both a module and monolithically, and it
seems to work quite well

Change notes:

v2)
* fixed for_each_present_cpu loops to be more correct as per Eric D.
* Converted exit path failures to BUG_ON as per Ben H.

v3)
* Converted del_timer to del_timer_sync to close race noted by Ben H.
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
CC: "David S. Miller" <davem@davemloft.net>
CC: Eric Dumazet <eric.dumazet@gmail.com>
CC: Ben Hutchings <bhutchings@solarflare.com>
Reviewed-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

netdev_alloc_skb() is used by networks driver in their RX path to
allocate an skb to receive an incoming frame.

With recent skb->head_frag infrastructure, it makes sense to change
netdev_alloc_skb() to use build_skb() and a frag allocator.

This permits a zero copy splice(socket->pipe), and better GRO or TCP
coalescing.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The padding destination or hop-by-hop option is called Pad1 and not Pad0.

See RFC2460 (4.2) or the IANA ipv6-parameters registry:
http://www.iana.org/assignments/ipv6-parameters/ipv6-parameters.xmlSigned-off-by: Eldad Zack <eldad@fogrefinery.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix some minor problems in comments of etherdevice.h
 * Warning is out dated, file hasn't moved or disappeared in many years and
    is unlikely to do so soon.
 * Capitalize Ethernet consistently since it is a proper name
 * Fix descriptive comment of padding
 * Spelling and grammar fix for alignment comment
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The patch removes unused return value from __delete_item() and
delete_item() methods in drivers/net/ppp/pppoe.c.
Signed-off-by: Rami Rosen <ramirose@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

bool conversions where possible.

__inline__ -> inline

space cleanups
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Under certain scenarios, it's possible that bursty manageability traffic
over the BMC-to-OS path may overrun the internal manageability receive
buffer causing dropped manageability packets. Clearing this bit prevents
this situation by interrupting coalescing to allow manageability traffic
through.
Signed-off-by: Matthew Vick <matthew.vick@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

The code seems to want to look at the last byte where the HW puts some
information. Since the skb->data area is never seen by the HW I guess it
does not work as expected. We pass the page address to the HW so I
*think* in order to get to the last byte where the information might be
one should use the page buffer and take a look.
This is of course not more than just compile tested.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

According to the comment, errata 23 says that the memory we allocate
can't cross a 64KiB boundary. In case of jumbo frames we allocate
complete pages which can never cross the 64KiB boundary because
PAGE_SIZE should be a multiple of 64KiB so we stop either before the
boundary or start after it but never cross it. Furthermore the check
seems bogus because it looks at skb->data which is not seen by the HW
at all because we only pass the DMA address of the page we allocated. So
I *think* the workaround is not required here.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

This define is needed by i217.
Reported-by: Bjorn Mork <bjorn@mork.no>
Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

Use the current logging style.

This enables use of dynamic debugging as well.

Convert printk(KERN_<LEVEL> to pr_<level>.
Add pr_fmt. Remove embedded prefixes, use
%s, __func__ instead.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Why use several macros when one will do?

Convert the multiple ND_PRINTKx macros to a single
ND_PRINTK macro.  Use the new net_<level>_ratelimited
mechanism too.

Add pr_fmt with "ICMPv6: " as prefix.
Remove embedded ICMPv6 prefixes from messages.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Convert printk(KERN_DEBUG to pr_debug which can
enable dynamic debugging.

Remove embedded prefixes from the conversions as
pr_fmt adds them.

Align arguments.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

bool/const conversions where possible

__inline__ -> inline

space cleanups
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

We test both "!skb_out" and "skb_out" here which is duplicative and
causes a static checker warning.  I considered that the intent might
have been to test "skb_in" but that's a valid pointer here.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>