Commit Graph

205 Commits

Author SHA1 Message Date
Mina Almasry
170aafe35c netdev: support binding dma-buf to netdevice
Add a netdev_dmabuf_binding struct which represents the
dma-buf-to-netdevice binding. The netlink API will bind the dma-buf to
rx queues on the netdevice. On the binding, the dma_buf_attach
& dma_buf_map_attachment will occur. The entries in the sg_table from
mapping will be inserted into a genpool to make it ready
for allocation.

The chunks in the genpool are owned by a dmabuf_chunk_owner struct which
holds the dma-buf offset of the base of the chunk and the dma_addr of
the chunk. Both are needed to use allocations that come from this chunk.

We create a new type that represents an allocation from the genpool:
net_iov. We setup the net_iov allocation size in the
genpool to PAGE_SIZE for simplicity: to match the PAGE_SIZE normally
allocated by the page pool and given to the drivers.

The user can unbind the dmabuf from the netdevice by closing the netlink
socket that established the binding. We do this so that the binding is
automatically unbound even if the userspace process crashes.

The binding and unbinding leaves an indicator in struct netdev_rx_queue
that the given queue is bound, and the binding is actuated by resetting
the rx queue using the queue API.

The netdev_dmabuf_binding struct is refcounted, and releases its
resources only when all the refs are released.

Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com>
Signed-off-by: Mina Almasry <almasrymina@google.com>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> # excluding netlink
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Link: https://patch.msgid.link/20240910171458.219195-4-almasrymina@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-11 20:44:31 -07:00
Heng Qi
f750dfe825 ethtool: provide customized dim profile management
The NetDIM library, currently leveraged by an array of NICs, delivers
excellent acceleration benefits. Nevertheless, NICs vary significantly
in their dim profile list prerequisites.

Specifically, virtio-net backends may present diverse sw or hw device
implementation, making a one-size-fits-all parameter list impractical.
On Alibaba Cloud, the virtio DPU's performance under the default DIM
profile falls short of expectations, partly due to a mismatch in
parameter configuration.

I also noticed that ice/idpf/ena and other NICs have customized
profilelist or placed some restrictions on dim capabilities.

Motivated by this, I tried adding new params for "ethtool -C" that provides
a per-device control to modify and access a device's interrupt parameters.

Usage
========
The target NIC is named ethx.

Assume that ethx only declares support for rx profile setting
(with DIM_PROFILE_RX flag set in profile_flags) and supports modification
of usec and pkt fields.

1. Query the currently customized list of the device

$ ethtool -c ethx
...
rx-profile:
{.usec =   1, .pkts = 256, .comps = n/a,},
{.usec =   8, .pkts = 256, .comps = n/a,},
{.usec =  64, .pkts = 256, .comps = n/a,},
{.usec = 128, .pkts = 256, .comps = n/a,},
{.usec = 256, .pkts = 256, .comps = n/a,}
tx-profile:   n/a

2. Tune
$ ethtool -C ethx rx-profile 1,1,n_2,n,n_3,3,n_4,4,n_n,5,n
"n" means do not modify this field.
$ ethtool -c ethx
...
rx-profile:
{.usec =   1, .pkts =   1, .comps = n/a,},
{.usec =   2, .pkts = 256, .comps = n/a,},
{.usec =   3, .pkts =   3, .comps = n/a,},
{.usec =   4, .pkts =   4, .comps = n/a,},
{.usec = 256, .pkts =   5, .comps = n/a,}
tx-profile:   n/a

3. Hint
If the device does not support some type of customized dim profiles,
the corresponding "n/a" will display.

If the "n/a" field is being modified, -EOPNOTSUPP will be reported.

Signed-off-by: Heng Qi <hengqi@linux.alibaba.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20240621101353.107425-4-hengqi@linux.alibaba.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-06-25 17:15:06 -07:00
Jason Xing
9b6a30febd net: allow rps/rfs related configs to be switched
After John Sperbeck reported a compile error if the CONFIG_RFS_ACCEL
is off, I found that I cannot easily enable/disable the config
because of lack of the prompt when using 'make menuconfig'. Therefore,
I decided to change rps/rfc related configs altogether.

Signed-off-by: Jason Xing <kernelxing@tencent.com>
Link: https://lore.kernel.org/r/20240605022932.33703-1-kerneljasonxing@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-06-06 13:18:48 +02:00
Oleksij Rempel
768cf84138 net: add IEEE 802.1q specific helpers
IEEE 802.1q specification provides recommendation and examples which can
be used as good default values for different drivers.

This patch implements mapping examples documented in IEEE 802.1Q-2022 in
Annex I "I.3 Traffic type to traffic class mapping" and IETF DSCP naming
and mapping DSCP to Traffic Type inspired by RFC8325.

This helpers will be used in followup patches for dsa/microchip DCB
implementation.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-05-08 10:35:09 +01:00
Jakub Kicinski
9f06f87fef net: skbuff: generalize the skb->decrypted bit
The ->decrypted bit can be reused for other crypto protocols.
Remove the direct dependency on TLS, add helpers to clean up
the ifdefs leaking out everywhere.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-04-06 17:34:31 +01:00
Breno Leitao
ea7f3cfaa5 net: bql: allow the config to be disabled
It is impossible to disable BQL individually today, since there is no
prompt for the Kconfig entry, so, the BQL is always enabled if SYSFS is
enabled.

Create a prompt entry for BQL, so, it could be enabled or disabled at
build time independently of SYSFS.

Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-02-18 10:19:21 +00:00
Quentin Deslandes
98e20e5e13 bpfilter: remove bpfilter
bpfilter was supposed to convert iptables filtering rules into
BPF programs on the fly, from the kernel, through a usermode
helper. The base code for the UMH was introduced in 2018, and
couple of attempts (2, 3) tried to introduce the BPF program
generate features but were abandoned.

bpfilter now sits in a kernel tree unused and unusable, occasionally
causing confusion amongst Linux users (4, 5).

As bpfilter is now developed in a dedicated repository on GitHub (6),
it was suggested a couple of times this year (LSFMM/BPF 2023,
LPC 2023) to remove the deprecated kernel part of the project. This
is the purpose of this patch.

[1]: https://lore.kernel.org/lkml/20180522022230.2492505-1-ast@kernel.org/
[2]: https://lore.kernel.org/bpf/20210829183608.2297877-1-me@ubique.spb.ru/#t
[3]: https://lore.kernel.org/lkml/20221224000402.476079-1-qde@naccy.de/
[4]: https://dxuuu.xyz/bpfilter.html
[5]: https://github.com/linuxkit/linuxkit/pull/3904
[6]: https://github.com/facebook/bpfilter

Signed-off-by: Quentin Deslandes <qde@naccy.de>
Link: https://lore.kernel.org/r/20231226130745.465988-1-qde@naccy.de
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-01-04 10:23:10 -08:00
Willem de Bruijn
b3098d32ed net: add skb_segment kunit test
Add unit testing for skb segment. This function is exercised by many
different code paths, such as GSO_PARTIAL or GSO_BY_FRAGS, linear
(with or without head_frag), frags or frag_list skbs, etc.

It is infeasible to manually run tests that cover all code paths when
making changes. The long and complex function also makes it hard to
establish through analysis alone that a patch has no unintended
side-effects.

Add code coverage through kunit regression testing. Introduce kunit
infrastructure for tests under net/core, and add this first test.

This first skb_segment test exercises a simple case: a linear skb.
Follow-on patches will parametrize the test and add more variants.

Tested: Built and ran the test with

    make ARCH=um mrproper

    ./tools/testing/kunit/kunit.py run \
        --kconfig_add CONFIG_NET=y \
        --kconfig_add CONFIG_DEBUG_KERNEL=y \
        --kconfig_add CONFIG_DEBUG_INFO=y \
        --kconfig_add=CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT=y \
        net_core_gso

Signed-off-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-11 10:39:01 +01:00
Arnd Bergmann
1dab47139e appletalk: remove ipddp driver
After the cops driver is removed, ipddp is now the only
CONFIG_DEV_APPLETALK but as far as I can tell, this also has no users
and can be removed, making appletalk support purely based on ethertalk,
using ethernet hardware.

Link: https://lore.kernel.org/netdev/e490dd0c-a65d-4acf-89c6-c06cb48ec880@app.fastmail.com/
Link: https://lore.kernel.org/netdev/9cac4fbd-9557-b0b8-54fa-93f0290a6fb8@schmorgal.com/
Cc: Doug Brown <doug@schmorgal.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20231009141139.1766345-1-arnd@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-10-10 17:49:00 -07:00
Daniel Borkmann
e420bed025 bpf: Add fd-based tcx multi-prog infra with link support
This work refactors and adds a lightweight extension ("tcx") to the tc BPF
ingress and egress data path side for allowing BPF program management based
on fds via bpf() syscall through the newly added generic multi-prog API.
The main goal behind this work which we also presented at LPC [0] last year
and a recent update at LSF/MM/BPF this year [3] is to support long-awaited
BPF link functionality for tc BPF programs, which allows for a model of safe
ownership and program detachment.

Given the rise in tc BPF users in cloud native environments, this becomes
necessary to avoid hard to debug incidents either through stale leftover
programs or 3rd party applications accidentally stepping on each others toes.
As a recap, a BPF link represents the attachment of a BPF program to a BPF
hook point. The BPF link holds a single reference to keep BPF program alive.
Moreover, hook points do not reference a BPF link, only the application's
fd or pinning does. A BPF link holds meta-data specific to attachment and
implements operations for link creation, (atomic) BPF program update,
detachment and introspection. The motivation for BPF links for tc BPF programs
is multi-fold, for example:

  - From Meta: "It's especially important for applications that are deployed
    fleet-wide and that don't "control" hosts they are deployed to. If such
    application crashes and no one notices and does anything about that, BPF
    program will keep running draining resources or even just, say, dropping
    packets. We at FB had outages due to such permanent BPF attachment
    semantics. With fd-based BPF link we are getting a framework, which allows
    safe, auto-detachable behavior by default, unless application explicitly
    opts in by pinning the BPF link." [1]

  - From Cilium-side the tc BPF programs we attach to host-facing veth devices
    and phys devices build the core datapath for Kubernetes Pods, and they
    implement forwarding, load-balancing, policy, EDT-management, etc, within
    BPF. Currently there is no concept of 'safe' ownership, e.g. we've recently
    experienced hard-to-debug issues in a user's staging environment where
    another Kubernetes application using tc BPF attached to the same prio/handle
    of cls_bpf, accidentally wiping all Cilium-based BPF programs from underneath
    it. The goal is to establish a clear/safe ownership model via links which
    cannot accidentally be overridden. [0,2]

BPF links for tc can co-exist with non-link attachments, and the semantics are
in line also with XDP links: BPF links cannot replace other BPF links, BPF
links cannot replace non-BPF links, non-BPF links cannot replace BPF links and
lastly only non-BPF links can replace non-BPF links. In case of Cilium, this
would solve mentioned issue of safe ownership model as 3rd party applications
would not be able to accidentally wipe Cilium programs, even if they are not
BPF link aware.

Earlier attempts [4] have tried to integrate BPF links into core tc machinery
to solve cls_bpf, which has been intrusive to the generic tc kernel API with
extensions only specific to cls_bpf and suboptimal/complex since cls_bpf could
be wiped from the qdisc also. Locking a tc BPF program in place this way, is
getting into layering hacks given the two object models are vastly different.

We instead implemented the tcx (tc 'express') layer which is an fd-based tc BPF
attach API, so that the BPF link implementation blends in naturally similar to
other link types which are fd-based and without the need for changing core tc
internal APIs. BPF programs for tc can then be successively migrated from classic
cls_bpf to the new tc BPF link without needing to change the program's source
code, just the BPF loader mechanics for attaching is sufficient.

For the current tc framework, there is no change in behavior with this change
and neither does this change touch on tc core kernel APIs. The gist of this
patch is that the ingress and egress hook have a lightweight, qdisc-less
extension for BPF to attach its tc BPF programs, in other words, a minimal
entry point for tc BPF. The name tcx has been suggested from discussion of
earlier revisions of this work as a good fit, and to more easily differ between
the classic cls_bpf attachment and the fd-based one.

For the ingress and egress tcx points, the device holds a cache-friendly array
with program pointers which is separated from control plane (slow-path) data.
Earlier versions of this work used priority to determine ordering and expression
of dependencies similar as with classic tc, but it was challenged that for
something more future-proof a better user experience is required. Hence this
resulted in the design and development of the generic attach/detach/query API
for multi-progs. See prior patch with its discussion on the API design. tcx is
the first user and later we plan to integrate also others, for example, one
candidate is multi-prog support for XDP which would benefit and have the same
'look and feel' from API perspective.

The goal with tcx is to have maximum compatibility to existing tc BPF programs,
so they don't need to be rewritten specifically. Compatibility to call into
classic tcf_classify() is also provided in order to allow successive migration
or both to cleanly co-exist where needed given its all one logical tc layer and
the tcx plus classic tc cls/act build one logical overall processing pipeline.

tcx supports the simplified return codes TCX_NEXT which is non-terminating (go
to next program) and terminating ones with TCX_PASS, TCX_DROP, TCX_REDIRECT.
The fd-based API is behind a static key, so that when unused the code is also
not entered. The struct tcx_entry's program array is currently static, but
could be made dynamic if necessary at a point in future. The a/b pair swap
design has been chosen so that for detachment there are no allocations which
otherwise could fail.

The work has been tested with tc-testing selftest suite which all passes, as
well as the tc BPF tests from the BPF CI, and also with Cilium's L4LB.

Thanks also to Nikolay Aleksandrov and Martin Lau for in-depth early reviews
of this work.

  [0] https://lpc.events/event/16/contributions/1353/
  [1] https://lore.kernel.org/bpf/CAEf4BzbokCJN33Nw_kg82sO=xppXnKWEncGTWCTB9vGCmLB6pw@mail.gmail.com
  [2] https://colocatedeventseu2023.sched.com/event/1Jo6O/tales-from-an-ebpf-programs-murder-mystery-hemanth-malla-guillaume-fournier-datadog
  [3] http://vger.kernel.org/bpfconf2023_material/tcx_meta_netdev_borkmann.pdf
  [4] https://lore.kernel.org/bpf/20210604063116.234316-1-memxor@gmail.com

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/r/20230719140858.13224-3-daniel@iogearbox.net
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-07-19 10:07:27 -07:00
Kurt Kanzenbach
c857946a4e net/core: Enable socket busy polling on -RT
Busy polling is currently not allowed on PREEMPT_RT, because it disables
preemption while invoking the NAPI callback. It is not possible to acquire
sleeping locks with disabled preemption. For details see commit
20ab39d13e ("net/core: disable NET_RX_BUSY_POLL on PREEMPT_RT").

However, strict cyclic and/or low latency network applications may prefer busy
polling e.g., using AF_XDP instead of interrupt driven communication.

The preempt_disable() is used in order to prevent the poll_owner and NAPI owner
to be preempted while owning the resource to ensure progress. Netpoll performs
busy polling in order to acquire the lock. NAPI is locked by setting the
NAPIF_STATE_SCHED flag. There is no busy polling if the flag is set and the
"owner" is preempted. Worst case is that the task owning NAPI gets preempted and
NAPI processing stalls.  This is can be prevented by properly prioritising the
tasks within the system.

Allow RX_BUSY_POLL on PREEMPT_RT if NETPOLL is disabled. Don't disable
preemption on PREEMPT_RT within the busy poll loop.

Tested on x86 hardware with v6.1-RT and v6.3-RT on Intel i225 (igc) with
AF_XDP/ZC sockets configured to run in busy polling mode.

Suggested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Kurt Kanzenbach <kurt@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-05-26 08:51:26 +01:00
Chuck Lever
88232ec1ec net/handshake: Add Kunit tests for the handshake consumer API
These verify the API contracts and help exercise lifetime rules for
consumer sockets and handshake_req structures.

One way to run these tests:

./tools/testing/kunit/kunit.py run --kunitconfig ./net/handshake/.kunitconfig

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-04-19 18:48:48 -07:00
Chuck Lever
3b3009ea8a net/handshake: Create a NETLINK service for handling handshake requests
When a kernel consumer needs a transport layer security session, it
first needs a handshake to negotiate and establish a session. This
negotiation can be done in user space via one of the several
existing library implementations, or it can be done in the kernel.

No in-kernel handshake implementations yet exist. In their absence,
we add a netlink service that can:

a. Notify a user space daemon that a handshake is needed.

b. Once notified, the daemon calls the kernel back via this
   netlink service to get the handshake parameters, including an
   open socket on which to establish the session.

c. Once the handshake is complete, the daemon reports the
   session status and other information via a second netlink
   operation. This operation marks that it is safe for the
   kernel to use the open socket and the security session
   established there.

The notification service uses a multicast group. Each handshake
mechanism (eg, tlshd) adopts its own group number so that the
handshake services are completely independent of one another. The
kernel can then tell via netlink_has_listeners() whether a handshake
service is active and prepared to handle a handshake request.

A new netlink operation, ACCEPT, acts like accept(2) in that it
instantiates a file descriptor in the user space daemon's fd table.
If this operation is successful, the reply carries the fd number,
which can be treated as an open and ready file descriptor.

While user space is performing the handshake, the kernel keeps its
muddy paws off the open socket. A second new netlink operation,
DONE, indicates that the user space daemon is finished with the
socket and it is safe for the kernel to use again. The operation
also indicates whether a session was established successfully.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-04-19 18:48:48 -07:00
Eric Dumazet
3948b05950 net: introduce a config option to tweak MAX_SKB_FRAGS
Currently, MAX_SKB_FRAGS value is 17.

For standard tcp sendmsg() traffic, no big deal because tcp_sendmsg()
attempts order-3 allocations, stuffing 32768 bytes per frag.

But with zero copy, we use order-0 pages.

For BIG TCP to show its full potential, we add a config option
to be able to fit up to 45 segments per skb.

This is also needed for BIG TCP rx zerocopy, as zerocopy currently
does not support skbs with frag list.

We have used MAX_SKB_FRAGS=45 value for years at Google before
we deployed 4K MTU, with no adverse effect, other than
a recent issue in mlx4, fixed in commit 26782aad00
("net/mlx4: MLX4_TX_BOUNCE_BUFFER_SIZE depends on MAX_SKB_FRAGS")

Back then, goal was to be able to receive full size (64KB) GRO
packets without the frag_list overhead.

Note that /proc/sys/net/core/max_skb_frags can also be used to limit
the number of fragments TCP can use in tx packets.

By default we keep the old/legacy value of 17 until we get
more coverage for the updated values.

Sizes of struct skb_shared_info on 64bit arches

MAX_SKB_FRAGS | sizeof(struct skb_shared_info):
==============================================
         17     320
         21     320+64  = 384
         25     320+128 = 448
         29     320+192 = 512
         33     320+256 = 576
         37     320+320 = 640
         41     320+384 = 704
         45     320+448 = 768

This inflation might cause problems for drivers assuming they could pack
both the incoming packet (for MTU=1500) and skb_shared_info in half a page,
using build_skb().

v3: fix build error when CONFIG_NET=n
v2: fix two build errors assuming MAX_SKB_FRAGS was "unsigned long"

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>
Link: https://lore.kernel.org/r/20230323162842.1935061-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-03-27 19:29:22 -07:00
Stephen Hemminger
1202cdd665 Remove DECnet support from kernel
DECnet is an obsolete network protocol that receives more attention
from kernel janitors than users. It belongs in computer protocol
history museum not in Linux kernel.

It has been "Orphaned" in kernel since 2010. The iproute2 support
for DECnet was dropped in 5.0 release. The documentation link on
Sourceforge says it is abandoned there as well.

Leave the UAPI alone to keep userspace programs compiling.
This means that there is still an empty neighbour table
for AF_DECNET.

The table of /proc/sys/net entries was updated to match
current directories and reformatted to be alphabetical.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Acked-by: David Ahern <dsahern@kernel.org>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-08-22 14:26:30 +01:00
Joe Damato
8610037e81 page_pool: Add allocation stats
Add per-pool statistics counters for the allocation path of a page pool.
These stats are incremented in softirq context, so no locking or per-cpu
variables are needed.

This code is disabled by default and a kernel config option is provided for
users who wish to enable them.

The statistics added are:
	- fast: successful fast path allocations
	- slow: slow path order-0 allocations
	- slow_high_order: slow path high order allocations
	- empty: ptr ring is empty, so a slow path allocation was forced.
	- refill: an allocation which triggered a refill of the cache
	- waive: pages obtained from the ptr ring that cannot be added to
	  the cache due to a NUMA mismatch.

Signed-off-by: Joe Damato <jdamato@fastly.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-03-03 09:55:28 +00:00
Jakub Kicinski
2c193f2cb1 net: kunit: add a test for dev_addr_lists
Add a KUnit test for the dev_addr API.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-11-20 12:25:57 +00:00
Sebastian Andrzej Siewior
20ab39d13e net/core: disable NET_RX_BUSY_POLL on PREEMPT_RT
napi_busy_loop() disables preemption and performs a NAPI poll. We can't acquire
sleeping locks with disabled preemption which would be required while
__napi_poll() invokes the callback of the driver.

A threaded interrupt performing the NAPI-poll can be preempted on PREEMPT_RT.
A RT thread on another CPU may observe NAPIF_STATE_SCHED bit set and busy-spin
until it is cleared or its spin time runs out. Given it is the task with the
highest priority it will never observe the NEED_RESCHED bit set.
In this case the time is better spent by simply sleeping.

The NET_RX_BUSY_POLL is disabled by default (the system wide sysctls for
poll/read are set to zero). Disabling NET_RX_BUSY_POLL on PREEMPT_RT to avoid
wrong locking context in case it is used.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/20211001145841.2308454-1-bigeasy@linutronix.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-10-01 15:45:10 -07:00
Jeremy Kerr
bc49d8169a mctp: Add MCTP base
Add basic Kconfig, an initial (empty) af_mctp source object, and
{AF,PF}_MCTP definitions, and the required definitions for a new
protocol type.

Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-29 15:06:49 +01:00
Daniel Borkmann
b24abcff91 bpf, kconfig: Add consolidated menu entry for bpf with core options
Right now, all core BPF related options are scattered in different Kconfig
locations mainly due to historic reasons. Moving forward, lets add a proper
subsystem entry under ...

  General setup  --->
    BPF subsystem  --->

... in order to have all knobs in a single location and thus ease BPF related
configuration. Networking related bits such as sockmap are out of scope for
the general setup and therefore better suited to remain in net/Kconfig.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/f23f58765a4d59244ebd8037da7b6a6b2fb58446.1620765074.git.daniel@iogearbox.net
2021-05-11 13:56:16 -07:00
Oleksij Rempel
4a52dd8fef net: selftest: fix build issue if INET is disabled
In case ethernet driver is enabled and INET is disabled, selftest will
fail to build.

Reported-by: Randy Dunlap <rdunlap@infradead.org>
Fixes: 3e1e58d64c ("net: add generic selftest support")
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20210428130947.29649-1-o.rempel@pengutronix.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-04-28 14:06:45 -07:00
Oleksij Rempel
3e1e58d64c net: add generic selftest support
Port some parts of the stmmac selftest and reuse it as basic generic selftest
library. This patch was tested with following combinations:
- iMX6DL FEC -> AT8035
- iMX6DL FEC -> SJA1105Q switch -> KSZ8081
- iMX6DL FEC -> SJA1105Q switch -> KSZ9031
- AR9331 ag71xx -> AR9331 PHY
- AR9331 ag71xx -> AR9331 switch -> AR9331 PHY

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-04-20 16:08:02 -07:00
Eric Dumazet
919067cc84 net: add CONFIG_PCPU_DEV_REFCNT
I was working on a syzbot issue, claiming one device could not be
dismantled because its refcount was -1

unregister_netdevice: waiting for sit0 to become free. Usage count = -1

It would be nice if syzbot could trigger a warning at the time
this reference count became negative.

This patch adds CONFIG_PCPU_DEV_REFCNT options which defaults
to per cpu variables (as before this patch) on SMP builds.

v2: free_dev label in alloc_netdev_mqs() is moved to avoid
    a compiler warning (-Wunused-label), as reported
    by kernel test robot <lkp@intel.com>

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-19 13:38:46 -07:00
Cong Wang
887596095e bpf: Clean up sockmap related Kconfigs
As suggested by John, clean up sockmap related Kconfigs:

Reduce the scope of CONFIG_BPF_STREAM_PARSER down to TCP stream
parser, to reflect its name.

Make the rest sockmap code simply depend on CONFIG_BPF_SYSCALL
and CONFIG_INET, the latter is still needed at this point because
of TCP/UDP proto update. And leave CONFIG_NET_SOCK_MSG untouched,
as it is used by non-sockmap cases.

Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Lorenz Bauer <lmb@cloudflare.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Jakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/bpf/20210223184934.6054-2-xiyou.wangcong@gmail.com
2021-02-26 12:28:03 -08:00
Tariq Toukan
4e1beecc3b net/sock: Add kernel config SOCK_RX_QUEUE_MAPPING
Use a new config SOCK_RX_QUEUE_MAPPING to compile-in the socket
RX queue field and logic, instead of the XPS config.
This breaks dependency in XPS, and allows selecting it from non-XPS
use cases, as we do in the next patch.

In addition, use the new flag to wrap the logic in sk_rx_queue_get()
and protect access to the sk_rx_queue_mapping field, while keeping
the function exposed unconditionally, just like sk_rx_queue_set()
and sk_rx_queue_clear().

Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Reviewed-by: Maxim Mikityanskiy <maximmi@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-02-11 19:08:06 -08:00
Arnd Bergmann
f54ec58fee wimax: move out to staging
There are no known users of this driver as of October 2020, and it will
be removed unless someone turns out to still need it in future releases.

According to https://en.wikipedia.org/wiki/List_of_WiMAX_networks, there
have been many public wimax networks, but it appears that many of these
have migrated to LTE or discontinued their service altogether.
As most PCs and phones lack WiMAX hardware support, the remaining
networks tend to use standalone routers. These almost certainly
run Linux, but not a modern kernel or the mainline wimax driver stack.

NetworkManager appears to have dropped userspace support in 2015
https://bugzilla.gnome.org/show_bug.cgi?id=747846, the
www.linuxwimax.org
site had already shut down earlier.

WiMax is apparently still being deployed on airport campus networks
("AeroMACS"), but in a frequency band that was not supported by the old
Intel 2400m (used in Sandy Bridge laptops and earlier), which is the
only driver using the kernel's wimax stack.

Move all files into drivers/staging/wimax, including the uapi header
files and documentation, to make it easier to remove it when it gets
to that. Only minimal changes are made to the source files, in order
to make it possible to port patches across the move.

Also remove the MAINTAINERS entry that refers to a broken mailing
list and website.

Acked-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-By: Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Suggested-by: Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2020-10-29 19:27:45 +01:00
Ido Schimmel
8ee2267ad3 drop_monitor: Convert to using devlink tracepoint
Convert drop monitor to use the recently introduced
'devlink_trap_report' tracepoint instead of having devlink call into
drop monitor.

This is both consistent with software originated drops ('kfree_skb'
tracepoint) and also allows drop monitor to be built as a module and
still report hardware originated drops.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-30 18:01:26 -07:00
Florian Fainelli
f3631ab08e net: ethtool: Remove PHYLIB direct dependency
Now that we have introduced ethtool_phy_ops and the PHY library
dynamically registers its operations with that function pointer, we can
remove the direct PHYLIB dependency in favor of using dynamic
operations.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-07 15:41:05 -07:00
Masahiro Yamada
a7f7f6248d treewide: replace '---help---' in Kconfig files with 'help'
Since commit 84af7a6194 ("checkpatch: kconfig: prefer 'help' over
'---help---'"), the number of '---help---' has been gradually
decreasing, but there are still more than 2400 instances.

This commit finishes the conversion. While I touched the lines,
I also fixed the indentation.

There are a variety of indentation styles found.

  a) 4 spaces + '---help---'
  b) 7 spaces + '---help---'
  c) 8 spaces + '---help---'
  d) 1 space + 1 tab + '---help---'
  e) 1 tab + '---help---'    (correct indentation)
  f) 1 tab + 1 space + '---help---'
  g) 1 tab + 2 spaces + '---help---'

In order to convert all of them to 1 tab + 'help', I ran the
following commend:

  $ find . -name 'Kconfig*' | xargs sed -i 's/^[[:space:]]*---help---/\thelp/'

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-14 01:57:21 +09:00
Andrew Lunn
11ca3c4261 net: ethtool: netlink: Add support for triggering a cable test
Add new ethtool netlink calls to trigger the starting of a PHY cable
test.

Add Kconfig'ury to ETHTOOL_NETLINK so that PHYLIB is not a module when
ETHTOOL_NETLINK is builtin, which would result in kernel linking errors.

v2:
Remove unwanted white space change
Remove ethnl_cable_test_act_ops and use doit handler
Rename cable_test_set_policy cable_test_act_policy
Remove ETHTOOL_MSG_CABLE_TEST_ACT_REPLY

v3:
Remove ETHTOOL_MSG_CABLE_TEST_ACT_REPLY from documentation
Remove unused cable_test_get_policy
Add Reviewed-by tags

v4:
Remove unwanted blank line

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Michal Kubecek <mkubecek@suse.cz>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-05-10 12:28:41 -07:00
Mauro Carvalho Chehab
c1e4535f24 docs: networking: convert pktgen.txt to ReST
- add SPDX header;
- adjust title markup;
- use bold markups on a few places;
- mark code blocks and literals as such;
- adjust identation, whitespaces and blank lines where needed;
- add to networking/index.rst.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-30 12:56:37 -07:00
Mauro Carvalho Chehab
1cec2cacaa docs: networking: convert ip-sysctl.txt to ReST
- add SPDX header;
- adjust titles and chapters, adding proper markups;
- mark code blocks and literals as such;
- mark lists as such;
- mark tables as such;
- use footnote markup;
- adjust identation, whitespaces and blank lines;
- add to networking/index.rst.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-28 14:40:18 -07:00
Pablo Neira Ayuso
2c64605b59 net: Fix CONFIG_NET_CLS_ACT=n and CONFIG_NFT_FWD_NETDEV={y, m} build
net/netfilter/nft_fwd_netdev.c: In function ‘nft_fwd_netdev_eval’:
    net/netfilter/nft_fwd_netdev.c:32:10: error: ‘struct sk_buff’ has no member named ‘tc_redirected’
      pkt->skb->tc_redirected = 1;
              ^~
    net/netfilter/nft_fwd_netdev.c:33:10: error: ‘struct sk_buff’ has no member named ‘tc_from_ingress’
      pkt->skb->tc_from_ingress = 1;
              ^~

To avoid a direct dependency with tc actions from netfilter, wrap the
redirect bits around CONFIG_NET_REDIRECT and move helpers to
include/linux/skbuff.h. Turn on this toggle from the ifb driver, the
only existing client of these bits in the tree.

This patch adds skb_set_redirected() that sets on the redirected bit
on the skbuff, it specifies if the packet was redirect from ingress
and resets the timestamp (timestamp reset was originally missing in the
netfilter bugfix).

Fixes: bcfabee1af ("netfilter: nft_fwd_netdev: allow to redirect to ifb via ingress")
Reported-by: noreply@ellerman.id.au
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-25 12:24:33 -07:00
Roman Kiryanov
98bda63e20 net: disable BRIDGE_NETFILTER by default
The description says 'If unsure, say N.' but
the module is built as M by default (once
the dependencies are satisfied).

When the module is selected (Y or M), it enables
NETFILTER_FAMILY_BRIDGE and SKB_EXTENSIONS
which alter kernel internal structures.

We (Android Studio Emulator) currently do not
use this module and think this it is more consistent
to have it disabled by default as opposite to
disabling it explicitly to prevent enabling
NETFILTER_FAMILY_BRIDGE and SKB_EXTENSIONS.

Signed-off-by: Roman Kiryanov <rkir@google.com>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-20 15:02:02 -08:00
Mat Martineau
f870fa0b57 mptcp: Add MPTCP socket stubs
Implements the infrastructure for MPTCP sockets.

MPTCP sockets open one in-kernel TCP socket per subflow. These subflow
sockets are only managed by the MPTCP socket that owns them and are not
visible from userspace. This commit allows a userspace program to open
an MPTCP socket with:

  sock = socket(AF_INET, SOCK_STREAM, IPPROTO_MPTCP);

The resulting socket is simply a wrapper around a single regular TCP
socket, without any of the MPTCP protocol implemented over the wire.

Co-developed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Co-developed-by: Peter Krystad <peter.krystad@linux.intel.com>
Signed-off-by: Peter Krystad <peter.krystad@linux.intel.com>
Co-developed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-24 13:44:07 +01:00
Michal Kubecek
2b4a8990b7 ethtool: introduce ethtool netlink interface
Basic genetlink and init infrastructure for the netlink interface, register
genetlink family "ethtool". Add CONFIG_ETHTOOL_NETLINK Kconfig option to
make the build optional. Add initial overall interface description into
Documentation/networking/ethtool-netlink.rst, further patches will add more
detailed information.

Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-27 16:40:01 -08:00
Richard Cochran
767ff48373 net: Add a layer for non-PHY MII time stamping drivers.
While PHY time stamping drivers can simply attach their interface
directly to the PHY instance, stand alone drivers require support in
order to manage their services.  Non-PHY MII time stamping drivers
have a control interface over another bus like I2C, SPI, UART, or via
a memory mapped peripheral.  The controller device will be associated
with one or more time stamping channels, each of which sits snoops in
on a MII bus.

This patch provides a glue layer that will enable time stamping
channels to find their controlling device.

Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-25 19:51:33 -08:00
Krzysztof Kozlowski
43da14110c net: Fix Kconfig indentation, continued
Adjust indentation from spaces to tab (+optional two spaces) as in
coding style.  This fixes various indentation mixups (seven spaces,
tab+one space, etc).

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-21 12:00:21 -08:00
Ido Schimmel
0f420b6c52 devlink: Add packet trap infrastructure
Add the basic packet trap infrastructure that allows device drivers to
register their supported packet traps and trap groups with devlink.

Each driver is expected to provide basic information about each
supported trap, such as name and ID, but also the supported metadata
types that will accompany each packet trapped via the trap. The
currently supported metadata type is just the input port, but more will
be added in the future. For example, output port and traffic class.

Trap groups allow users to set the action of all member traps. In
addition, users can retrieve per-group statistics in case per-trap
statistics are too narrow. In the future, the trap group object can be
extended with more attributes, such as policer settings which will limit
the amount of traffic generated by member traps towards the CPU.

Beside registering their packet traps with devlink, drivers are also
expected to report trapped packets to devlink along with relevant
metadata. devlink will maintain packets and bytes statistics for each
packet trap and will potentially report the trapped packet with its
metadata to user space via drop monitor netlink channel.

The interface towards the drivers is simple and allows devlink to set
the action of the trap. Currently, only two actions are supported:
'trap' and 'drop'. When set to 'trap', the device is expected to provide
the sole copy of the packet to the driver which will pass it to devlink.
When set to 'drop', the device is expected to drop the packet and not
send a copy to the driver. In the future, more actions can be added,
such as 'mirror'.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-08-17 12:40:08 -07:00
Ard Biesheuvel
c681edae33 net: ipv4: move tcp_fastopen server side code to SipHash library
Using a bare block cipher in non-crypto code is almost always a bad idea,
not only for security reasons (and we've seen some examples of this in
the kernel in the past), but also for performance reasons.

In the TCP fastopen case, we call into the bare AES block cipher one or
two times (depending on whether the connection is IPv4 or IPv6). On most
systems, this results in a call chain such as

  crypto_cipher_encrypt_one(ctx, dst, src)
    crypto_cipher_crt(tfm)->cit_encrypt_one(crypto_cipher_tfm(tfm), ...);
      aesni_encrypt
        kernel_fpu_begin();
        aesni_enc(ctx, dst, src); // asm routine
        kernel_fpu_end();

It is highly unlikely that the use of special AES instructions has a
benefit in this case, especially since we are doing the above twice
for IPv6 connections, instead of using a transform which can process
the entire input in one go.

We could switch to the cbcmac(aes) shash, which would at least get
rid of the duplicated overhead in *some* cases (i.e., today, only
arm64 has an accelerated implementation of cbcmac(aes), while x86 will
end up using the generic cbcmac template wrapping the AES-NI cipher,
which basically ends up doing exactly the above). However, in the given
context, it makes more sense to use a light-weight MAC algorithm that
is more suitable for the purpose at hand, such as SipHash.

Since the output size of SipHash already matches our chosen value for
TCP_FASTOPEN_COOKIE_SIZE, and given that it accepts arbitrary input
sizes, this greatly simplifies the code as well.

NOTE: Server farms backing a single server IP for load balancing purposes
      and sharing a single fastopen key will be adversely affected by
      this change unless all systems in the pool receive their kernel
      upgrades at the same time.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-17 13:56:26 -07:00
Thomas Gleixner
ec8f24b7fa treewide: Add SPDX license identifier - Makefile/Kconfig
Add SPDX license identifiers to all Make/Kconfig files which:

 - Have no license information of any form

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

  GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21 10:50:46 +02:00
Jiri Pirko
f6b19b354d net: devlink: select NET_DEVLINK from drivers
Some drivers are becoming more dependent on NET_DEVLINK being selected
in configuration. With upcoming compat functions, the behavior would be
wrong in case devlink was not compiled in. So make the drivers select
NET_DEVLINK and rely on the functions being there, not just stubs.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-03-24 14:55:31 -04:00
Jakub Kicinski
f4b6bcc700 net: devlink: turn devlink into a built-in
Being able to build devlink as a module causes growing pains.
First all drivers had to add a meta dependency to make sure
they are not built in when devlink is built as a module.  Now
we are struggling to invoke ethtool compat code reliably.

Make devlink code built-in, users can still not build it at
all but the dynamically loadable module option is removed.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-02-26 08:49:05 -08:00
Peter Oskolkov
b251f9f63a bpf: make LWTUNNEL_BPF dependent on INET
Lightweight tunnels are L3 constructs that are used with IP/IP6.

For example, lwtunnel_xmit is called from ip_output.c and
ip6_output.c only.

Make the dependency explicit at least for LWT-BPF, as now they
call into IP routing.

V2: added "Reported-by" below.

Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Peter Oskolkov <posk@google.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-02-16 01:06:30 +01:00
Florian Westphal
de8bda1d22 net: convert bridge_nf to use skb extension infrastructure
This converts the bridge netfilter (calling iptables hooks from bridge)
facility to use the extension infrastructure.

The bridge_nf specific hooks in skb clone and free paths are removed, they
have been replaced by the skb_ext hooks that do the same as the bridge nf
allocations hooks did.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-19 11:21:37 -08:00
Florian Westphal
df5042f4c5 sk_buff: add skb extension infrastructure
This adds an optional extension infrastructure, with ispec (xfrm) and
bridge netfilter as first users.
objdiff shows no changes if kernel is built without xfrm and br_netfilter
support.

The third (planned future) user is Multipath TCP which is still
out-of-tree.
MPTCP needs to map logical mptcp sequence numbers to the tcp sequence
numbers used by individual subflows.

This DSS mapping is read/written from tcp option space on receive and
written to tcp option space on transmitted tcp packets that are part of
and MPTCP connection.

Extending skb_shared_info or adding a private data field to skb fclones
doesn't work for incoming skb, so a different DSS propagation method would
be required for the receive side.

mptcp has same requirements as secpath/bridge netfilter:

1. extension memory is released when the sk_buff is free'd.
2. data is shared after cloning an skb (clone inherits extension)
3. adding extension to an skb will COW the extension buffer if needed.

The "MPTCP upstreaming" effort adds SKB_EXT_MPTCP extension to store the
mapping for tx and rx processing.

Two new members are added to sk_buff:
1. 'active_extensions' byte (filling a hole), telling which extensions
   are available for this skb.
   This has two purposes.
   a) avoids the need to initialize the pointer.
   b) allows to "delete" an extension by clearing its bit
   value in ->active_extensions.

   While it would be possible to store the active_extensions byte
   in the extension struct instead of sk_buff, there is one problem
   with this:
    When an extension has to be disabled, we can always clear the
    bit in skb->active_extensions.  But in case it would be stored in the
    extension buffer itself, we might have to COW it first, if
    we are dealing with a cloned skb.  On kmalloc failure we would
    be unable to turn an extension off.

2. extension pointer, located at the end of the sk_buff.
   If the active_extensions byte is 0, the pointer is undefined,
   it is not initialized on skb allocation.

This adds extra code to skb clone and free paths (to deal with
refcount/free of extension area) but this replaces similar code that
manages skb->nf_bridge and skb->sp structs in the followup patches of
the series.

It is possible to add support for extensions that are not preseved on
clones/copies.

To do this, it would be needed to define a bitmask of all extensions that
need copy/cow semantics, and change __skb_ext_copy() to check
->active_extensions & SKB_EXT_PRESERVE_ON_CLONE, then just set
->active_extensions to 0 on the new clone.

This isn't done here because all extensions that get added here
need the copy/cow semantics.

v2:
Allocate entire extension space using kmem_cache.
Upside is that this allows better tracking of used memory,
downside is that we will allocate more space than strictly needed in
most cases (its unlikely that all extensions are active/needed at same
time for same skb).
The allocated memory (except the small extension header) is not cleared,
so no additonal overhead aside from memory usage.

Avoid atomic_dec_and_test operation on skb_ext_put()
by using similar trick as kfree_skbmem() does with fclone_ref:
If recount is 1, there is no concurrent user and we can free right away.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-19 11:21:37 -08:00
Daniel Borkmann
604326b41a bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.

This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.

Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.

The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.

Joint work with John.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-15 12:23:19 -07:00
Stephen Hemminger
e446a2760f net: remove blank lines at end of file
Several files have extra line at end of file.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-24 14:10:43 -07:00
Sridhar Samudrala
30c8bd5aa8 net: Introduce generic failover module
The failover module provides a generic interface for paravirtual drivers
to register a netdev and a set of ops with a failover instance. The ops
are used as event handlers that get called to handle netdev register/
unregister/link change/name change events on slave pci ethernet devices
with the same mac address as the failover netdev.

This enables paravirtual drivers to use a VF as an accelerated low latency
datapath. It also allows migration of VMs with direct attached VFs by
failing over to the paravirtual datapath when the VF is unplugged.

Signed-off-by: Sridhar Samudrala <sridhar.samudrala@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-28 22:59:54 -04:00
Alexei Starovoitov
d2ba09c17a net: add skeleton of bpfilter kernel module
bpfilter.ko consists of bpfilter_kern.c (normal kernel module code)
and user mode helper code that is embedded into bpfilter.ko

The steps to build bpfilter.ko are the following:
- main.c is compiled by HOSTCC into the bpfilter_umh elf executable file
- with quite a bit of objcopy and Makefile magic the bpfilter_umh elf file
  is converted into bpfilter_umh.o object file
  with _binary_net_bpfilter_bpfilter_umh_start and _end symbols
  Example:
  $ nm ./bld_x64/net/bpfilter/bpfilter_umh.o
  0000000000004cf8 T _binary_net_bpfilter_bpfilter_umh_end
  0000000000004cf8 A _binary_net_bpfilter_bpfilter_umh_size
  0000000000000000 T _binary_net_bpfilter_bpfilter_umh_start
- bpfilter_umh.o and bpfilter_kern.o are linked together into bpfilter.ko

bpfilter_kern.c is a normal kernel module code that calls
the fork_usermode_blob() helper to execute part of its own data
as a user mode process.

Notice that _binary_net_bpfilter_bpfilter_umh_start - end
is placed into .init.rodata section, so it's freed as soon as __init
function of bpfilter.ko is finished.
As part of __init the bpfilter.ko does first request/reply action
via two unix pipe provided by fork_usermode_blob() helper to
make sure that umh is healthy. If not it will kill it via pid.

Later bpfilter_process_sockopt() will be called from bpfilter hooks
in get/setsockopt() to pass iptable commands into umh via bpfilter.ko

If admin does 'rmmod bpfilter' the __exit code bpfilter.ko will
kill umh as well.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-23 13:23:40 -04:00