Helpers for mitigating ACK loops by rate-limiting dupacks sent in
response to incoming out-of-window packets.

This patch includes:

- rate-limiting logic
- sysctl to control how often we allow dupacks to out-of-window packets
- SNMP counter for cases where we rate-limited our dupack sending

The rate-limiting logic in this patch decides to not send dupacks in
response to out-of-window segments if (a) they are SYNs or pure ACKs
and (b) the remote endpoint is sending them faster than the configured
rate limit.

We rate-limit our responses rather than blocking them entirely or
resetting the connection, because legitimate connections can rely on
dupacks in response to some out-of-window segments. For example, zero
window probes are typically sent with a sequence number that is below
the current window, and ZWPs thus expect to thus elicit a dupack in
response.

We allow dupacks in response to TCP segments with data, because these
may be spurious retransmissions for which the remote endpoint wants to
receive DSACKs. This is safe because segments with data can't
realistically be part of ACK loops, which by their nature consist of
each side sending pure/data-less ACKs to each other.

The dupack interval is controlled by a new sysctl knob,
tcp_invalid_ratelimit, given in milliseconds, in case an administrator
needs to dial this upward in the face of a high-rate DoS attack. The
name and units are chosen to be analogous to the existing analogous
knob for ICMP, icmp_ratelimit.

The default value for tcp_invalid_ratelimit is 500ms, which allows at
most one such dupack per 500ms. This is chosen to be 2x faster than
the 1-second minimum RTO interval allowed by RFC 6298 (section 2, rule
2.4). We allow the extra 2x factor because network delay variations
can cause packets sent at 1 second intervals to be compressed and
arrive much closer.
Reported-by: Avery Fay <avery@mixpanel.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Flow alloc needs to initialize unmasked key pointer. Otherwise
it can crash kernel trying to free random unmasked-key pointer.

general protection fault: 0000 [#1] SMP
3.19.0-rc6-net-next+ #457
Hardware name: Supermicro X7DWU/X7DWU, BIOS  1.1 04/30/2008
RIP: 0010:[<ffffffff8111df0e>] [<ffffffff8111df0e>] kfree+0xac/0x196
Call Trace:
 [<ffffffffa060bd87>] flow_free+0x21/0x59 [openvswitch]
 [<ffffffffa060bde0>] ovs_flow_free+0x21/0x23 [openvswitch]
 [<ffffffffa0605b4a>] ovs_packet_cmd_execute+0x2f3/0x35f [openvswitch]
 [<ffffffffa0605995>] ? ovs_packet_cmd_execute+0x13e/0x35f [openvswitch]
 [<ffffffff811fe6fb>] ? nla_parse+0x4f/0xec
 [<ffffffff8139a2fc>] genl_family_rcv_msg+0x26d/0x2c9
 [<ffffffff8107620f>] ? __lock_acquire+0x90e/0x9aa
 [<ffffffff8139a3be>] genl_rcv_msg+0x66/0x89
 [<ffffffff8139a358>] ? genl_family_rcv_msg+0x2c9/0x2c9
 [<ffffffff81399591>] netlink_rcv_skb+0x3e/0x95
 [<ffffffff81399898>] ? genl_rcv+0x18/0x37
 [<ffffffff813998a7>] genl_rcv+0x27/0x37
 [<ffffffff81399033>] netlink_unicast+0x103/0x191
 [<ffffffff81399382>] netlink_sendmsg+0x2c1/0x310
 [<ffffffff811007ad>] ? might_fault+0x50/0xa0
 [<ffffffff8135c773>] do_sock_sendmsg+0x5f/0x7a
 [<ffffffff8135c799>] sock_sendmsg+0xb/0xd
 [<ffffffff8135cacf>] ___sys_sendmsg+0x1a3/0x218
 [<ffffffff8113e54b>] ? get_close_on_exec+0x86/0x86
 [<ffffffff8115a9d0>] ? fsnotify+0x32c/0x348
 [<ffffffff8115a720>] ? fsnotify+0x7c/0x348
 [<ffffffff8113e5f5>] ? __fget+0xaa/0xbf
 [<ffffffff8113e54b>] ? get_close_on_exec+0x86/0x86
 [<ffffffff8135cccd>] __sys_sendmsg+0x3d/0x5e
 [<ffffffff8135cd02>] SyS_sendmsg+0x14/0x16
 [<ffffffff81411852>] system_call_fastpath+0x12/0x17

Fixes: 74ed7ab9("openvswitch: Add support for unique flow IDs.")
CC: Joe Stringer <joestringer@nicira.com>
Reported-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Hariprasad Shenai says:

====================
Add support to dump some hw debug info

This patch series adds support to dump sensor info, dump Transport Processor
event trace, dump Upper Layer Protocol RX module command trace, dump mailbox
contents and dump Transport Processor congestion control configuration.

Will send a separate patch series for all the hw stats patches, by moving them
to ethtool.

The patches series is created against 'net-next' tree.
And includes patches on cxgb4 driver.

We have included all the maintainers of respective drivers. Kindly review the
change and let us know in case of any review comments.

V2: Dopped all hw stats related patches. Added a new patch which adds support to
dump congestion control table.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Dump Transport Processor modules congestion control configuration
Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Adds support to dump the current contents of mailbox and the driver which owns
it.
Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Dump Upper Layer Protocol RX module command trace
Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Dump Transport Processor event trace.
Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Dump out various chip sensor information. Currently Chip Temperature
and Core Voltage.
Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Sathya Perla says:

====================
be2net: patch set

Hi Dave, pls consider applying the following patch-set to the
net-next tree. It has 5 code/style cleanup patches and 4 patches that
add functionality to the driver.

Patch 1 moves routines that were not needed to be in be.h to the respective
src files, to avoid unnecessary compilation.

Patch 2 replaces (1 << x) with BIT(x) macro

Patch 3 refactors code that checks if a FW flash file is compatible
with the adapter. The code is now refactored into 2 routines, the first one
gets the file type from the image file and the 2nd routine checks if the
file type is compatible with the adapter.

Patch 4 adds compatibility checks for flashing a FW image on the new
Skyhawk P2 HW revision.

Patch 5 adds support for a new "offset based" flashing scheme, wherein
the driver informs the FW of the offset at which each component in the flash
file is to be flashed at. This helps flashing components that were
previously not recognized by the running FW.

Patch 6 simplifies the be_cmd_rx_filter() routine, by passing to it the
filter flags already used in the FW cmd, instead of the netdev flags that
were converted to the FW-cmd flags.

Patch 7 introduces helper routines in be_set_rx_mode() and be_vid_config()
to improve code readability.

Patch 8 adds processing of port-misconfig async event sent by the FW.

Patch 9 removes unnecessary swapping of a field in the TX desc.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

The 32-bit fields of a tx-wrb are little endian. The driver is currently
using be_dws_le_to_cpu() routine to swap (cpu to le) all the fields of
a tx-wrb. So, the rsvd field is also unnecessarily swapped.

This patch fixes this by individually swapping the required fields.
Also, the type of the fields in eth_tx_wrb{} is now changed to __le32
from u32 to avoid sparse warnings.
Signed-off-by: Sathya Perla <sathya.perla@emulex.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch adds support for processing the port misconfigure async
event generated by the FW. This event is generated typically when an
optical module is incorrectly installed or is faulty.

This patch also moves the port_name field to the adapter struct for
logging the event. As the be_cmd_query_port_name() call is now moved
to be_get_config(), it is modified to use the mailbox instead of MCCQ
Signed-off-by: Sathya Perla <sathya.perla@emulex.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch re-factors the filter setting (uc-list, mc-list, promisc, vlan)
code in be_set_rx_mode() and be_vid_config() to make it more readable
and reduce code duplication.
This patch adds a separate field to track the state/mode of filtering,
along with moving all the filtering related fields to one place in be
be_adapter structure.
Signed-off-by: Sathya Perla <sathya.perla@emulex.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch passes BE_IF_FLAGS_XXX flags to be_cmd_rx_filter() routine
instead of the IFF_XXX flags. Doing this gets rid of the code to convert
the IFF_XXX flags to the BE_IF_FLAGS_XXX used by the FW cmd. The patch
also removes code for setting if_flags_mask that was duplicated for each
filter mode.
Signed-off-by: Sathya Perla <sathya.perla@emulex.com>
Signed-off-by: Kalesh AP <kalesh.purayil@emulex.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

While sending FW update cmds to the FW, the driver specifies the "type"
of each component that needs to be flashed. The FW then picks the offset
in the flash area at which the componnet is to be flashed. This doesn't work
when new components that the current FW doesn't recognize, need to be
flashed. Recent FWs (10.2 and above) support a scheme of FW-update wherein
the "offset" of the component in the flash area can be specified instead
of the "type". This patch uses the "offset" based FW-update mechanism and
only when it fails, it fallsback to the old "type" based update.
Signed-off-by: Vasundhara Volam <vasundhara.volam@emulex.com>
Signed-off-by: Sathya Perla <sathya.perla@emulex.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Skyhawk-B0 FW UFI is not compatible to flash on Skyhawk-P2 ASIC.
But, Skyhawk-P2 FW UFI is compatible with both B0 and P2 chips.
Signed-off-by: Vasundhara Volam <vasundhara.volam@emulex.com>
Signed-off-by: Sathya Perla <sathya.perla@emulex.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch re-factors the code that checks for flash file compatibility with
the chip type, for better readability, as follows:
	- be_get_ufi_type() returns the UFI type from the flash file
	- be_check_ufi_compatibility() checks if the UFI type is compatible
	  with the adapter/chip that is being flashed
Signed-off-by: Vasundhara Volam <vasundhara.volam@emulex.com>
Signed-off-by: Sathya Perla <sathya.perla@emulex.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

BIT(x) is the preffered usage.
Signed-off-by: Vasundhara Volam <vasundhara.volam@emulex.com>
Signed-off-by: Sathya Perla <sathya.perla@emulex.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Routines that are called only inside one src file must remain in that
file itself. Including them in a header file that is used for exporting
routine/struct definitions, causes unnecessary compilation of other
src files, when such a routine is modified.
Signed-off-by: Sathya Perla <sathya.perla@emulex.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch fixes a missing bridge port check caught by smatch.

setlink/dellink of attributes like vlans can come for a bridge device
and there is no need to offload those today. So, this patch adds a bridge
port check. (In these cases however, the BRIDGE_SELF flags will always be set
and we may not hit a problem with the current code).

smatch complaint:

The patch 68e331c7: "bridge: offload bridge port attributes to
switch asic if feature flag set" from Jan 29, 2015, leads to the
following Smatch complaint:

net/bridge/br_netlink.c:552 br_setlink()
	 error: we previously assumed 'p' could be null (see line 518)

net/bridge/br_netlink.c
   517
   518		if (p && protinfo) {
                    ^
Check for NULL.
Reported-By: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Jeff Kirsher says:

====================
Intel Wired LAN Driver Updates 2015-02-05

This series contains updates to fm10k, ixgbe and ixgbevf.

Matthew fixes an issue where fm10k does not properly drop the upper-most four
bits on of the VLAN ID due to type promotion, so resolve the issue by not
masking off the bits, but by throwing an error if the VLAN ID is out-of-bounds.
Then cleans up two cases where variables were not being used, but were
being set, so just remove the unused variables.

Don cleans up sparse errors in the x550 family file for ixgbe.  Fixed up
a redundant setting of the default value for set_rxpba, which was done
twice accidentally.  Cleaned up the probe routine to remove a redundant
attempt to identify the PHY, which could lead to a panic on x550.  Added
support for VXLAN receive checksum offload in x550 hardware.  Added the
Ethertype Anti-spoofing feature for affected devices.

Emil enables ixgbe and ixgbevf to allow multiple queues in SRIOV mode.
Adds RSS support for x550 per VF.  Fixed up a couple of issues introduced
in commit 2b509c0c ("ixgbe: cleanup ixgbe_ndo_set_vf_vlan"), fixed
setting of the VLAN inside ixgbe_enable_port_vlan() and disable the
"hide VLAN" bit in PFQDE when port VLAN is disabled.  Cleaned up the
setting of vlan_features by enabling all features at once.  Fixed the
ordering of the shutdown patch so that we attempt to shutdown the rings
more gracefully.  We shutdown the main Rx filter in the case of Rx and we
set the carrier_off state in the case of Tx so that packets stop being
delivered from outside the driver.  Then we shutdown interrupts and NAPI,
then finally stop the rings from performing DMA and clean them.  Added
code to allow for Tx hang checking to provide more robust debug info in
the event of a transmit unit hang in ixgbevf.  Cleaned up ixgbevf logic
dealing with link up/down by breaking down the link detection and up/down
events into separate functions, similar to how these events are handled
in other drivers.  Combined the ixgbevf reset and watchdog tasks into a
single task so that we can avoid multiple schedules of the reset task when
we have a reset event needed due to either the mailbox going down or
transmit packets being present on a link down.

v2: Fixed up patch #03 of the series to remove the variable type change
    based on feedback from David Laight
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Hayes Wang says:

====================
r8152: adjust the code

V2:
Correct the subject of patch #5. Replace "link feed" with "line feed".

v1:
Code adjustment.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Use BIT macro to replace (1 << bits).
Signed-off-by: Hayes Wang <hayeswang@realtek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

vlan_get_protocol() has been defined and use it to replace
get_protocol().
Signed-off-by: Hayes Wang <hayeswang@realtek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Keep NETIF_F_HW_VLAN_CTAG_RX and NETIF_F_HW_VLAN_CTAG_TX at the
same line.
Signed-off-by: Hayes Wang <hayeswang@realtek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

It is unnecessary to accress the hw register if the device is unplugged.
Signed-off-by: Hayes Wang <hayeswang@realtek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Replace (tp->speed & LINK_STATUS) with netif_carrier_ok().
Signed-off-by: Hayes Wang <hayeswang@realtek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Set LPM timer to 500us, except for RTL_VER_04 which doesn't link at
USB 3.0.
Signed-off-by: Hayes Wang <hayeswang@realtek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

If a error occurs when submitting rx, skip the remaining submissions
and try to submit them again next time.
Signed-off-by: Hayes Wang <hayeswang@realtek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Commit 083735f4 ("rds: switch rds_message_copy_from_user() to iov_iter")
breaks rds_message_copy_from_user() semantics on success, and causes it
to return nbytes copied, when it should return 0.  This commit fixes that bug.
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The macro rdsdebug is defined as

  pr_debug("%s(): " fmt, __func__ , ##args)

Hence it doesn't make sense to include the name of the calling
function explicitly in the format string passed to rdsdebug.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: David S. Miller <davem@davemloft.net>

OVS userspace already probes the openvswitch kernel module for
OVS_ACTION_ATTR_SET_MASKED support.  This patch adds the kernel module
implementation of masked set actions.

The existing set action sets many fields at once.  When only a subset
of the IP header fields, for example, should be modified, all the IP
fields need to be exact matched so that the other field values can be
copied to the set action.  A masked set action allows modification of
an arbitrary subset of the supported header bits without requiring the
rest to be matched.

Masked set action is now supported for all writeable key types, except
for the tunnel key.  The set tunnel action is an exception as any
input tunnel info is cleared before action processing starts, so there
is no tunnel info to mask.

The kernel module converts all (non-tunnel) set actions to masked set
actions.  This makes action processing more uniform, and results in
less branching and duplicating the action processing code.  When
returning actions to userspace, the fully masked set actions are
converted back to normal set actions.  We use a kernel internal action
code to be able to tell the userspace provided and converted masked
set actions apart.
Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Acked-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Florian Fainelli says:

====================
net: dsa: bcm_sf2: GPHY power down

This patch series implement GPHY power up and down in the SF2 switch
driver in order to conserve power whenever possible (e.g: port is brought
down or unused during Wake-on-LAN).
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Implement the power on/off recommended procedure for the Single GPHY we
have on our Starfighter 2 switch. In order to make sure we get proper
LED link/activity signaling during suspend, switch the link indication
from the Switch/MAC to the PHY.

Finally, since the GPHY needs to be reset to be put in low power mode,
we will loose any context applied to it: workarounds, EEE etc.. so we
need to call phy_init_hw() to get our fixups re-applied successfully.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Move the code that touches the single GPHY register from
bcm_sf2_sw_resume() to a separate function since we will have to
enable/disable the GPHY from different locations, and we want the code
to be self-contained.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

NFC: 3.20 second pull request

This is the second NFC pull request for 3.20.

It brings:

- NCI NFCEE (NFC Execution Environment, typically an embedded or
  external secure element) discovery and enabling/disabling support.
  In order to communicate with an NFCEE, we also added NCI's logical
  connections support to the NCI stack.

- HCI over NCI protocol support. Some secure elements only understand
  HCI and thus we need to send them HCI frames when they're part of
  an NCI chipset.

- NFC_EVT_TRANSACTION userspace API addition. Whenever an application
  running on a secure element needs to notify its host counterpart,
  we send an NFC_EVENT_SE_TRANSACTION event to userspace through the
  NFC netlink socket.

- Secure element and HCI transaction event support for the st21nfcb
  chipset.
Signed-off-by: David S. Miller <davem@davemloft.net>

The remove logic properly searched the remaining chain for a matching
entry with an identical hash but it did this while searching from both
the old and new table. Instead in order to not leave stale references
behind we need to:

 1. When growing and searching from the new table:
    Search remaining chain for entry with same hash to avoid having
    the new table directly point to a entry with a different hash.

 2. When shrinking and searching from the old table:
    Check if the element after the removed would create a cross
    reference and avoid it if so.

These bugs were present from the beginning in nft_hash.

Also, both insert functions calculated the hash based on the mask of
the new table. This worked while growing. Wwhile shrinking, the mask
of the inew table is smaller than the mask of the old table. This lead
to a bit not being taken into account when selecting the bucket lock
and thus caused the wrong bucket to be locked eventually.

Fixes: 7e1e7763 ("lib: Resizable, Scalable, Concurrent Hash Table")
Fixes: 97defe1e ("rhashtable: Per bucket locks & deferred expansion/shrinking")
Reported-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Thomas Graf says:

====================
rhashtable fixes

This series fixes all remaining known issues with rhashtable that
have been reported. In particular the race condition reported by
Ying Xue.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

During a resize, when two buckets in the larger table map to
a single bucket in the smaller table and the new table has already
been (partially) linked to the old table. Removal of an element
may result the bucket in the larger table to point to entries
which all hash to a different value than the bucket index. Thus
causing two buckets to point to the same sub chain after unzipping.
This is not illegal *during* the resize phase but after it has
completed.

Keep the old table around until all of the unzipping is done to
allow the removal code to only search for matching hashed entries
during this special period.
Reported-by: Ying Xue <ying.xue@windriver.com>
Fixes: 97defe1e ("rhashtable: Per bucket locks & deferred expansion/shrinking")
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Catch hash miscalculations which result in hard to track down race
conditions.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

This simplifies debugging of locking violations if compiled with
CONFIG_PROVE_LOCKING.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>