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>
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>
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>
FQ has a fast path for skb attached to a socket, as it does not
have to compute a flow hash. But for other packets, FQ being non
stochastic means that hosts exposed to random Internet traffic
can allocate million of flows structure (104 bytes each) pretty
easily. Not only host can OOM, but lookup in RB trees can take
too much cpu and memory resources.
This patch adds a new attribute, orphan_mask, that is adding
possibility of having a stochastic hash for orphaned skb.
Its default value is 1024 slots, to mimic SFQ behavior.
Note: This does not apply to locally generated TCP traffic,
and no locally generated traffic will share a flow structure
with another perfect or stochastic flow.
This patch also handles the specific case of SYNACK messages:
They are attached to the listener socket, and therefore all map
to a single hash bucket. If listener have set SO_MAX_PACING_RATE,
hoping to have new accepted socket inherit this rate, SYNACK
might be paced and even dropped.
This is very similar to an internal patch Google have used more
than one year.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Last round of updates for net-next:
* revert a patch that caused a regression with mesh userspace (Bob)
* fix a number of suspend/resume related races
(from Emmanuel, Luca and myself - we'll look at backporting later)
* add software implementations for new ciphers (Jouni)
* add a new ACPI ID for Broadcom's rfkill (Mika)
* allow using netns FD for wireless (Vadim)
* some other cleanups (various)
Signed-off-by: David S. Miller <davem@davemloft.net>
Add timestamping option SOF_TIMESTAMPING_OPT_TSONLY. For transmit
timestamps, this loops timestamps on top of empty packets.
Doing so reduces the pressure on SO_RCVBUF. Payload inspection and
cmsg reception (aside from timestamps) are no longer possible. This
works together with a follow on patch that allows administrators to
only allow tx timestamping if it does not loop payload or metadata.
Signed-off-by: Willem de Bruijn <willemb@google.com>
----
Changes (rfc -> v1)
- add documentation
- remove unnecessary skb->len test (thanks to Richard Cochran)
Signed-off-by: David S. Miller <davem@davemloft.net>
NFC_EVT_TRANSACTION is sent through netlink in order for a
specific application running on a secure element to notify
userspace of an event. Typically the secure element application
counterpart on the host could interpret that event and act
upon it.
Forwarded information contains:
- SE host generating the event
- Application IDentifier doing the operation
- Applications parameters
Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Such a feature doesn't exist and isn't really needed since you
probably won't have enough interfaces to make it worthwhile, so
just remove that from the documentation.
Reported-by: booto [on IRC]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Previous commit is based on a wrong assumption, fdb messages are always sent
into the netns where the interface stands (see vxlan_fdb_notify()).
These fdb messages doesn't embed the rtnl attribute IFLA_LINK_NETNSID, thus we
need to add it (useful to interpret NDA_IFINDEX or NDA_DST for example).
Note also that vxlan_nlmsg_size() was not updated.
Fixes: 193523bf93 ("vxlan: advertise netns of vxlan dev in fdb msg")
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Conflicts:
arch/arm/boot/dts/imx6sx-sdb.dts
net/sched/cls_bpf.c
Two simple sets of overlapping changes.
Signed-off-by: David S. Miller <davem@davemloft.net>
Previously, flows were manipulated by userspace specifying a full,
unmasked flow key. This adds significant burden onto flow
serialization/deserialization, particularly when dumping flows.
This patch adds an alternative way to refer to flows using a
variable-length "unique flow identifier" (UFID). At flow setup time,
userspace may specify a UFID for a flow, which is stored with the flow
and inserted into a separate table for lookup, in addition to the
standard flow table. Flows created using a UFID must be fetched or
deleted using the UFID.
All flow dump operations may now be made more terse with OVS_UFID_F_*
flags. For example, the OVS_UFID_F_OMIT_KEY flag allows responses to
omit the flow key from a datapath operation if the flow has a
corresponding UFID. This significantly reduces the time spent assembling
and transacting netlink messages. With all OVS_UFID_F_OMIT_* flags
enabled, the datapath only returns the UFID and statistics for each flow
during flow dump, increasing ovs-vswitchd revalidator performance by 40%
or more.
Signed-off-by: Joe Stringer <joestringer@nicira.com>
Acked-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The kernel forcefully applies MTU values received in router
advertisements provided the new MTU is less than the current. This
behavior is undesirable when the user space is managing the MTU. Instead
a sysctl flag 'accept_ra_mtu' is introduced such that the user space
can control whether or not RA provided MTU updates should be applied. The
default behavior is unchanged; user space must explicitly set this flag
to 0 for RA MTUs to be ignored.
Signed-off-by: Harout Hedeshian <harouth@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Netlink FDB messages are sent in the link netns. The header of these messages
contains the ifindex (ndm_ifindex) of the netdevice, but this ifindex is
unusable in case of x-netns vxlan.
I named the new attribute NDA_NDM_IFINDEX_NETNSID, to avoid confusion with
NDA_IFINDEX.
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The userspace may want to delay the the first scheduled scan or
net-detect cycle. Add an optional attribute to the scheduled scan
configuration to pass the delay to be (optionally) used by the driver.
Signed-off-by: Luciano Coelho <luciano.coelho@intel.com>
[add the attribute to the policy to validate it]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Added new NL80211_ATTR_NETNS_FD which allows to
set namespace via nl80211 by fd.
Signed-off-by: Vadim Kochan <vadim4j@gmail.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Pull networking fixes from David Miller:
1) Socket addresses returned in the error queue need to be fully
initialized before being passed on to userspace, fix from Willem de
Bruijn.
2) Interrupt handling fixes to davinci_emac driver from Tony Lindgren.
3) Fix races between receive packet steering and cpu hotplug, from Eric
Dumazet.
4) Allowing netlink sockets to subscribe to unknown multicast groups
leads to crashes, don't allow it. From Johannes Berg.
5) One to many socket races in SCTP fixed by Daniel Borkmann.
6) Put in a guard against the mis-use of ipv6 atomic fragments, from
Hagen Paul Pfeifer.
7) Fix promisc mode and ethtool crashes in sh_eth driver, from Ben
Hutchings.
8) NULL deref and double kfree fix in sxgbe driver from Girish K.S and
Byungho An.
9) cfg80211 deadlock fix from Arik Nemtsov.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (36 commits)
s2io: use snprintf() as a safety feature
r8152: remove sram_read
r8152: remove generic_ocp_read before writing
bgmac: activate irqs only if there is nothing to poll
bgmac: register napi before the device
sh_eth: Fix ethtool operation crash when net device is down
sh_eth: Fix promiscuous mode on chips without TSU
ipv6: stop sending PTB packets for MTU < 1280
net: sctp: fix race for one-to-many sockets in sendmsg's auto associate
genetlink: synchronize socket closing and family removal
genetlink: disallow subscribing to unknown mcast groups
genetlink: document parallel_ops
net: rps: fix cpu unplug
net: davinci_emac: Add support for emac on dm816x
net: davinci_emac: Fix ioremap for devices with MDIO within the EMAC address space
net: davinci_emac: Fix incomplete code for getting the phy from device tree
net: davinci_emac: Free clock after checking the frequency
net: davinci_emac: Fix runtime pm calls for davinci_emac
net: davinci_emac: Fix hangs with interrupts
ip: zero sockaddr returned on error queue
...
Some further updates for net-next:
* fix network-manager which was broken by the previous changes
* fix delete-station events, which were broken by me making the
genlmsg_end() mistake
* fix a timer left running during suspend in some race conditions
that would cause an annoying (but harmless) warning
* (less important, but in the tree already) remove 80+80 MHz rate
reporting since the spec doesn't distinguish it from 160 MHz;
as the bitrate they're both 160 MHz bandwidth
Signed-off-by: David S. Miller <davem@davemloft.net>
This tc action allows you to retrieve the connection tracking mark
This action has been used heavily by openwrt for a few years now.
There are known limitations currently:
doesn't work for initial packets, since we only query the ct table.
Fine given use case is for returning packets
no implicit defrag.
frags should be rare so fix later..
won't work for more complex tasks, e.g. lookup of other extensions
since we have no means to store results
we still have a 2nd lookup later on via normal conntrack path.
This shouldn't break anything though since skb->nfct isn't altered.
V2:
remove unnecessary braces (Jiri)
change the action identifier to 14 (Jiri)
Fix some stylistic issues caught by checkpatch
V3:
Move module params to bottom (Cong)
Get rid of tcf_hashinfo_init and friends and conform to newer API (Cong)
Acked-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds a new attribute (IFLA_LINK_NETNSID) which contains the 'link'
netns id when this netns is different from the netns where the interface
stands (for example for x-net interfaces like ip tunnels).
With this attribute, it's possible to interpret correctly all advertised
information (like IFLA_LINK, etc.).
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
With this patch, a user can define an id for a peer netns by providing a FD or a
PID. These ids are local to the netns where it is added (ie valid only into this
netns).
The main function (ie the one exported to other module), peernet2id(), allows to
get the id of a peer netns. If no id has been assigned by the user, this
function allocates one.
These ids will be used in netlink messages to point to a peer netns, for example
in case of a x-netns interface.
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull input subsystem fixes from Dmitry Torokhov.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
Input: uinput - fix ioctl nr overflow for UI_GET_SYSNAME/VERSION
Input: I8042 - add Acer Aspire 7738 to the nomux list
Input: elantech - support new ICs types for version 4
Input: i8042 - reset keyboard to fix Elantech touchpad detection
MAINTAINERS: remove Dmitry Torokhov's alternate address
This action provides a possibility to exec custom BPF code.
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
Here's a big pile of changes for this round.
We have
* a lot of regulatory code changes to deal with the
way newer Intel devices handle this
* a change to drop packets while disconnecting from
an AP instead of trying to wait for them
* a new attempt at improving the tailroom accounting
to not kick in too much for performance reasons
* improvements in wireless link statistics
* many other small improvements and small fixes that
didn't seem necessary for 3.19 (e.g. in hwsim which
is testing only code)
Conflicts:
drivers/staging/rtl8723au/os_dep/ioctl_cfg80211.c
Minor overlapping changes.
Signed-off-by: David S. Miller <davem@davemloft.net>
For some reason, we made the bandwidth separate flags, which
is rather confusing - a single rate cannot have different
bandwidths at the same time.
Change this to no longer be flags but use a separate field
for the bandwidth ('bw') instead.
While at it, add support for 5 and 10 MHz rates - these are
reported as regular legacy rates with their real bitrate,
but tagged as 5/10 now to make it easier to distinguish them.
In the nl80211 API, the flags are preserved, but the code
now can also clearly only set a single one of the flags.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
During the CAN FD standardization process within the ISO it turned out that
the failure detection capability has to be improved.
The CAN in Automation organization (CiA) defined the already implemented CAN
FD controllers as 'non-ISO' and the upcoming improved CAN FD controllers as
'ISO' compliant. See at http://www.can-cia.com/index.php?id=1937
Finally there will be three types of CAN FD controllers in the future:
1. ISO compliant (fixed)
2. non-ISO compliant (fixed, like the M_CAN IP v3.0.1 in m_can.c)
3. ISO/non-ISO CAN FD controllers (switchable, like the PEAK USB FD)
So the current M_CAN driver for the M_CAN IP v3.0.1 has to expose its non-ISO
implementation by setting the CAN_CTRLMODE_FD_NON_ISO ctrlmode at startup.
As this bit cannot be switched at configuration time CAN_CTRLMODE_FD_NON_ISO
must not be set in ctrlmode_supported of the current M_CAN driver.
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
