Daniel Borkmann says:

====================
pull-request: bpf-next 2022-01-24

We've added 80 non-merge commits during the last 14 day(s) which contain
a total of 128 files changed, 4990 insertions(+), 895 deletions(-).

The main changes are:

1) Add XDP multi-buffer support and implement it for the mvneta driver,
   from Lorenzo Bianconi, Eelco Chaudron and Toke Høiland-Jørgensen.

2) Add unstable conntrack lookup helpers for BPF by using the BPF kfunc
   infra, from Kumar Kartikeya Dwivedi.

3) Extend BPF cgroup programs to export custom ret value to userspace via
   two helpers bpf_get_retval() and bpf_set_retval(), from YiFei Zhu.

4) Add support for AF_UNIX iterator batching, from Kuniyuki Iwashima.

5) Complete missing UAPI BPF helper description and change bpf_doc.py script
   to enforce consistent & complete helper documentation, from Usama Arif.

6) Deprecate libbpf's legacy BPF map definitions and streamline XDP APIs to
   follow tc-based APIs, from Andrii Nakryiko.

7) Support BPF_PROG_QUERY for BPF programs attached to sockmap, from Di Zhu.

8) Deprecate libbpf's bpf_map__def() API and replace users with proper getters
   and setters, from Christy Lee.

9) Extend libbpf's btf__add_btf() with an additional hashmap for strings to
   reduce overhead, from Kui-Feng Lee.

10) Fix bpftool and libbpf error handling related to libbpf's hashmap__new()
    utility function, from Mauricio Vásquez.

11) Add support to BTF program names in bpftool's program dump, from Raman Shukhau.

12) Fix resolve_btfids build to pick up host flags, from Connor O'Brien.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (80 commits)
  selftests, bpf: Do not yet switch to new libbpf XDP APIs
  selftests, xsk: Fix rx_full stats test
  bpf: Fix flexible_array.cocci warnings
  xdp: disable XDP_REDIRECT for xdp frags
  bpf: selftests: add CPUMAP/DEVMAP selftests for xdp frags
  bpf: selftests: introduce bpf_xdp_{load,store}_bytes selftest
  net: xdp: introduce bpf_xdp_pointer utility routine
  bpf: generalise tail call map compatibility check
  libbpf: Add SEC name for xdp frags programs
  bpf: selftests: update xdp_adjust_tail selftest to include xdp frags
  bpf: test_run: add xdp_shared_info pointer in bpf_test_finish signature
  bpf: introduce frags support to bpf_prog_test_run_xdp()
  bpf: move user_size out of bpf_test_init
  bpf: add frags support to xdp copy helpers
  bpf: add frags support to the bpf_xdp_adjust_tail() API
  bpf: introduce bpf_xdp_get_buff_len helper
  net: mvneta: enable jumbo frames if the loaded XDP program support frags
  bpf: introduce BPF_F_XDP_HAS_FRAGS flag in prog_flags loading the ebpf program
  net: mvneta: add frags support to XDP_TX
  xdp: add frags support to xdp_return_{buff/frame}
  ...
====================

Link: https://lore.kernel.org/r/20220124221235.18993-1-daniel@iogearbox.netSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Revert commit 54435652 ("selftests/bpf: switch to new libbpf XDP APIs")
for now given this will heavily conflict with 4b27480d ("bpf/selftests:
convert xdp_link test to ASSERT_* macros") upon merge. Andrii agreed to redo
the conversion cleanly after trees merged.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>

Merge tag 'linux-can-fixes-for-5.17-20220124' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can

Marc Kleine-Budde says:

====================
pull-request: can 2022-01-24

The first patch updates the email address of Brian Silverman from his
former employer to his private address.

The next patch fixes DT bindings information for the tcan4x5x SPI CAN
driver.

The following patch targets the m_can driver and fixes the
introduction of FIFO bulk read support.

Another patch for the tcan4x5x driver, which fixes the max register
value for the regmap config.

The last patch for the flexcan driver marks the RX mailbox support for
the MCF5441X as support.

* tag 'linux-can-fixes-for-5.17-20220124' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can:
  can: flexcan: mark RX via mailboxes as supported on MCF5441X
  can: tcan4x5x: regmap: fix max register value
  can: m_can: m_can_fifo_{read,write}: don't read or write from/to FIFO if length is 0
  dt-bindings: can: tcan4x5x: fix mram-cfg RX FIFO config
  mailmap: update email address of Brian Silverman
====================

Link: https://lore.kernel.org/r/20220124175955.3464134-1-mkl@pengutronix.deSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Most flexcan IP cores support 2 RX modes:
- FIFO
- mailbox

The flexcan IP core on the MCF5441X cannot receive CAN RTR messages
via mailboxes. However the mailbox mode is more performant. The commit

| 1c45f577 ("can: flexcan: add ethtool support to change rx-rtr setting during runtime")

added support to switch from FIFO to mailbox mode on these cores.

After testing the mailbox mode on the MCF5441X by Angelo Dureghello,
this patch marks it (without RTR capability) as supported. Further the
IP core overview table is updated, that RTR reception via mailboxes is
not supported.

Link: https://lore.kernel.org/all/20220121084425.3141218-1-mkl@pengutronix.deTested-by: Angelo Dureghello <angelo@kernel-space.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

The MRAM of the tcan4x5x has a size of 2K and starts at 0x8000. There
are no further registers in the tcan4x5x making 0x87fc the biggest
addressable register.

This patch fixes the max register value of the regmap config from
0x8ffc to 0x87fc.

Fixes: 6e1caaf8 ("can: tcan4x5x: fix max register value")
Link: https://lore.kernel.org/all/20220119064011.2943292-1-mkl@pengutronix.deSigned-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

In order to optimize FIFO access, especially on m_can cores attached
to slow busses like SPI, in patch

| e3938177 ("can: m_can: Disable IRQs on FIFO bus errors")

bulk read/write support has been added to the m_can_fifo_{read,write}
functions.

That change leads to the tcan driver to call
regmap_bulk_{read,write}() with a length of 0 (for CAN frames with 0
data length). regmap treats this as an error:

| tcan4x5x spi1.0 tcan4x5x0: FIFO write returned -22

This patch fixes the problem by not calling the
cdev->ops->{read,write)_fifo() in case of a 0 length read/write.

Fixes: e3938177 ("can: m_can: Disable IRQs on FIFO bus errors")
Link: https://lore.kernel.org/all/20220114155751.2651888-1-mkl@pengutronix.de
Cc: stable@vger.kernel.org
Cc: Matt Kline <matt@bitbashing.io>
Cc: Chandrasekar Ramakrishnan <rcsekar@samsung.com>
Reported-by: Michael Anochin <anochin@photo-meter.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

This tcan4x5x only comes with 2K of MRAM, a RX FIFO with a dept of 32
doesn't fit into the MRAM. Use a depth of 16 instead.

Fixes: 4edd396a ("dt-bindings: can: tcan4x5x: Add DT bindings for TCAN4x5X driver")
Link: https://lore.kernel.org/all/20220119062951.2939851-1-mkl@pengutronix.deSigned-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

Brian Silverman's address at bluerivertech.com is not valid anymore,
use Brian's private email address instead.

Link: https://lore.kernel.org/all/20220110082359.2019735-1-mkl@pengutronix.de
Cc: Brian Silverman <bsilver16384@gmail.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

Fix the rx_full stats test so that it correctly reports pass even when
the fill ring is not full of buffers.

Fixes: 872a1184 ("selftests: xsk: Put the same buffer only once in the fill ring")
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/bpf/20220121123508.12759-1-magnus.karlsson@gmail.com

Zero-length and one-element arrays are deprecated, see:
Documentation/process/deprecated.rst

Flexible-array members should be used instead.

Generated by: scripts/coccinelle/misc/flexible_array.cocci

Fixes: c1ff181f ("selftests/bpf: Extend kfunc selftests")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: kernel test robot <lkp@intel.com>
Signed-off-by: Julia Lawall <julia.lawall@inria.fr>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/bpf/alpine.DEB.2.22.394.2201221206320.12220@hadrien

The tx_coalesce and mii_irq are not used at all now, so remove them.
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Simplify code by using bitmap_weight() and bitmap_zero() instead of
hand-writing these functions.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Igor Russkikh <irusskikh@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When 'ping' changes to use PING socket instead of RAW socket by:

   # sysctl -w net.ipv4.ping_group_range="0 100"

the selftests 'router_broadcast.sh' will fail, as such command

  # ip vrf exec vrf-h1 ping -I veth0 198.51.100.255 -b

can't receive the response skb by the PING socket. It's caused by mismatch
of sk_bound_dev_if and dif in ping_rcv() when looking up the PING socket,
as dif is vrf-h1 if dif's master was set to vrf-h1.

This patch is to fix this regression by also checking the sk_bound_dev_if
against sdif so that the packets can stil be received even if the socket
is not bound to the vrf device but to the real iif.

Fixes: c319b4d7 ("net: ipv4: add IPPROTO_ICMP socket kind")
Reported-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

We encountered a crash in smc_setsockopt() and it is caused by
accessing smc->clcsock after clcsock was released.

 BUG: kernel NULL pointer dereference, address: 0000000000000020
 #PF: supervisor read access in kernel mode
 #PF: error_code(0x0000) - not-present page
 PGD 0 P4D 0
 Oops: 0000 [#1] PREEMPT SMP PTI
 CPU: 1 PID: 50309 Comm: nginx Kdump: loaded Tainted: G E     5.16.0-rc4+ #53
 RIP: 0010:smc_setsockopt+0x59/0x280 [smc]
 Call Trace:
  <TASK>
  __sys_setsockopt+0xfc/0x190
  __x64_sys_setsockopt+0x20/0x30
  do_syscall_64+0x34/0x90
  entry_SYSCALL_64_after_hwframe+0x44/0xae
 RIP: 0033:0x7f16ba83918e
  </TASK>

This patch tries to fix it by holding clcsock_release_lock and
checking whether clcsock has already been released before access.

In case that a crash of the same reason happens in smc_getsockopt()
or smc_switch_to_fallback(), this patch also checkes smc->clcsock
in them too. And the caller of smc_switch_to_fallback() will identify
whether fallback succeeds according to the return value.

Fixes: fd57770d ("net/smc: wait for pending work before clcsock release_sock")
Link: https://lore.kernel.org/lkml/5dd7ffd1-28e2-24cc-9442-1defec27375e@linux.ibm.com/T/Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Acked-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

With previous bug fix, ->wait_capability flag is no longer needed and can
be removed.

Fixes: 249168ad ("ibmvnic: Make CRQ interrupt tasklet wait for all capabilities crqs")
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.ibm.com>
Reviewed-by: Dany Madden <drt@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ibmvnic_tasklet() continuously spins waiting for responses to all
capability requests. It does this to avoid encountering an error
during initialization of the vnic. However if there is a bug in the
VIOS and we do not receive a response to one or more queries the
tasklet ends up spinning continuously leading to hard lock ups.

If we fail to receive a message from the VIOS it is reasonable to
timeout the login attempt rather than spin indefinitely in the tasklet.

Fixes: 249168ad ("ibmvnic: Make CRQ interrupt tasklet wait for all capabilities crqs")
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.ibm.com>
Reviewed-by: Dany Madden <drt@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

We use ->running_cap_crqs to determine when the ibmvnic_tasklet() should
send out the next protocol message type. i.e when we get back responses
to all our QUERY_CAPABILITY CRQs we send out REQUEST_CAPABILITY crqs.
Similiary, when we get responses to all the REQUEST_CAPABILITY crqs, we
send out the QUERY_IP_OFFLOAD CRQ.

We currently increment ->running_cap_crqs as we send out each CRQ and
have the ibmvnic_tasklet() send out the next message type, when this
running_cap_crqs count drops to 0.

This assumes that all the CRQs of the current type were sent out before
the count drops to 0. However it is possible that we send out say 6 CRQs,
get preempted and receive all the 6 responses before we send out the
remaining CRQs. This can result in ->running_cap_crqs count dropping to
zero before all messages of the current type were sent and we end up
sending the next protocol message too early.

Instead initialize the ->running_cap_crqs upfront so the tasklet will
only send the next protocol message after all responses are received.

Use the cap_reqs local variable to also detect any discrepancy (either
now or in future) in the number of capability requests we actually send.

Currently only send_query_cap() is affected by this behavior (of sending
next message early) since it is called from the worker thread (during
reset) and from application thread (during ->ndo_open()) and they can be
preempted. send_request_cap() is only called from the tasklet  which
processes CRQ responses sequentially, is not be affected.  But to
maintain the existing symmtery with send_query_capability() we update
send_request_capability() also.

Fixes: 249168ad ("ibmvnic: Make CRQ interrupt tasklet wait for all capabilities crqs")
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.ibm.com>
Reviewed-by: Dany Madden <drt@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

If auto-priority-failover (APF) is enabled and there are at least two
backing devices of different priorities, some resets like fail-over,
change-param etc can cause at least two back to back failovers. (Failover
from high priority backing device to lower priority one and then back
to the higher priority one if that is still functional).

Depending on the timimg of the two failovers it is possible to trigger
a "hard" reset and for the hard reset to fail due to failovers. When this
occurs, the driver assumes that the network is unstable and disables the
VNIC for a 60-second "settling time". This in turn can cause the ethtool
command to fail with "No such device" while the vnic automatically recovers
a little while later.

Given that it's possible to have two back to back failures, allow for extra
failures before disabling the vnic for the settling time.

Fixes: f15fde9d ("ibmvnic: delay next reset if hard reset fails")
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.ibm.com>
Reviewed-by: Dany Madden <drt@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

During IP fragmentation we sanitize IP options. This means overwriting
options which should not be copied with NOPs. Only the first fragment
has the original, full options.

ip_fraglist_prepare() copies the IP header and options from previous
fragment to the next one. Commit 19c3401a ("net: ipv4: place control
buffer handling away from fragmentation iterators") moved sanitizing
options before ip_fraglist_prepare() which means options are sanitized
and then overwritten again with the old values.

Fixing this is not enough, however, nor did the sanitization work
prior to aforementioned commit.

ip_options_fragment() (which does the sanitization) uses ipcb->opt.optlen
for the length of the options. ipcb->opt of fragments is not populated
(it's 0), only the head skb has the state properly built. So even when
called at the right time ip_options_fragment() does nothing. This seems
to date back all the way to v2.5.44 when the fast path for pre-fragmented
skbs had been introduced. Prior to that ip_options_build() would have been
called for every fragment (in fact ever since v2.5.44 the fragmentation
handing in ip_options_build() has been dead code, I'll clean it up in
-next).

In the original patch (see Link) caixf mentions fixing the handling
for fragments other than the second one, but I'm not sure how _any_
fragment could have had their options sanitized with the code
as it stood.

Tested with python (MTU on lo lowered to 1000 to force fragmentation):

  import socket
  s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
  s.setsockopt(socket.IPPROTO_IP, socket.IP_OPTIONS,
               bytearray([7,4,5,192, 20|0x80,4,1,0]))
  s.sendto(b'1'*2000, ('127.0.0.1', 1234))

Before:

IP (tos 0x0, ttl 64, id 1053, offset 0, flags [+], proto UDP (17), length 996, options (RR [bad length 4] [bad ptr 5] 192.148.4.1,,RA value 256))
    localhost.36500 > localhost.search-agent: UDP, length 2000
IP (tos 0x0, ttl 64, id 1053, offset 968, flags [+], proto UDP (17), length 996, options (RR [bad length 4] [bad ptr 5] 192.148.4.1,,RA value 256))
    localhost > localhost: udp
IP (tos 0x0, ttl 64, id 1053, offset 1936, flags [none], proto UDP (17), length 100, options (RR [bad length 4] [bad ptr 5] 192.148.4.1,,RA value 256))
    localhost > localhost: udp

After:

IP (tos 0x0, ttl 96, id 42549, offset 0, flags [+], proto UDP (17), length 996, options (RR [bad length 4] [bad ptr 5] 192.148.4.1,,RA value 256))
    localhost.51607 > localhost.search-agent: UDP, bad length 2000 > 960
IP (tos 0x0, ttl 96, id 42549, offset 968, flags [+], proto UDP (17), length 996, options (NOP,NOP,NOP,NOP,RA value 256))
    localhost > localhost: udp
IP (tos 0x0, ttl 96, id 42549, offset 1936, flags [none], proto UDP (17), length 100, options (NOP,NOP,NOP,NOP,RA value 256))
    localhost > localhost: udp

RA (20 | 0x80) is now copied as expected, RR (7) is "NOPed out".

Link: https://lore.kernel.org/netdev/20220107080559.122713-1-ooppublic@163.com/
Fixes: 19c3401a ("net: ipv4: place control buffer handling away from fragmentation iterators")
Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: caixf <ooppublic@163.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

After commit:7866a621 ("dev: add per net_device packet type chains"),
we can not get packet types that are bound to a specified net device by
/proc/net/ptype, this patch fix the regression.

Run "tcpdump -i ens192 udp -nns0" Before and after apply this patch:

Before:
  [root@localhost ~]# cat /proc/net/ptype
  Type Device      Function
  0800          ip_rcv
  0806          arp_rcv
  86dd          ipv6_rcv

After:
  [root@localhost ~]# cat /proc/net/ptype
  Type Device      Function
  ALL  ens192   tpacket_rcv
  0800          ip_rcv
  0806          arp_rcv
  86dd          ipv6_rcv

v1 -> v2:
  - fix the regression rather than adding new /proc API as
    suggested by Stephen Hemminger.

Fixes: 7866a621 ("dev: add per net_device packet type chains")
Signed-off-by: Jianguo Wu <wujianguo@chinatelecom.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>

bond_option_active_slave_get_rcu() should not be used in rtnl_mutex as it
use rcu_dereference(). Replace to rcu_dereference_rtnl() so we also can use
this function in rtnl protected context.

With this update, we can rmeove the rcu_read_lock/unlock in
bonding .ndo_eth_ioctl and .get_ts_info.
Reported-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Fixes: 94dd016a ("bond: pass get_ts_info and SIOC[SG]HWTSTAMP ioctl to active device")
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Commit ce0aa27f ("sfp: add sfp-bus to bridge between network devices
and sfp cages") added code which finds SFP bus DT node even if the node
is disabled with status = "disabled". Because of this, when phylink is
created, it ends with non-null .sfp_bus member, even though the SFP
module is not probed (because the node is disabled).

We need to ignore disabled SFP bus node.

Fixes: ce0aa27f ("sfp: add sfp-bus to bridge between network devices and sfp cages")
Signed-off-by: Marek Behún <kabel@kernel.org>
Cc: stable@vger.kernel.org # 2203cbf2 ("net: sfp: move fwnode parsing into sfp-bus layer")
Signed-off-by: David S. Miller <davem@davemloft.net>

The IOAM queue-depth data field was added a few weeks ago,
but the test unit was not updated accordingly.
Reported-by: kernel test robot <oliver.sang@intel.com>
Fixes: b63c5478 ("ipv6: ioam: Support for Queue depth data field")
Signed-off-by: Justin Iurman <justin.iurman@uliege.be>
Link: https://lore.kernel.org/r/20220121173449.26918-1-justin.iurman@uliege.beSigned-off-by: Jakub Kicinski <kuba@kernel.org>

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memcpy(), memmove(), and memset(), avoid
intentionally writing across neighboring fields.

Use struct_group() to capture the fields to be reset, so that memset()
can be appropriately bounds-checked by the compiler.

Cc: Matthieu Baerts <matthieu.baerts@tessares.net>
Cc: mptcp@lists.linux.dev
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Link: https://lore.kernel.org/r/20220121073935.1154263-1-keescook@chromium.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Improve retransmission backoff by only backing off when we retransmit data
packets rather than when we set the lost ack timer.

To this end:

 (1) In rxrpc_resend(), use rxrpc_get_rto_backoff() when setting the
     retransmission timer and only tell it that we are retransmitting if we
     actually have things to retransmit.

     Note that it's possible for the retransmission algorithm to race with
     the processing of a received ACK, so we may see no packets needing
     retransmission.

 (2) In rxrpc_send_data_packet(), don't bump the backoff when setting the
     ack_lost_at timer, as it may then get bumped twice.

With this, when looking at one particular packet, the retransmission
intervals were seen to be 1.5ms, 2ms, 3ms, 5ms, 9ms, 17ms, 33ms, 71ms,
136ms, 264ms, 544ms, 1.088s, 2.1s, 4.2s and 8.3s.

Fixes: c410bf01 ("rxrpc: Fix the excessive initial retransmission timeout")
Suggested-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Marc Dionne <marc.dionne@auristor.com>
Tested-by: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Link: https://lore.kernel.org/r/164138117069.2023386.17446904856843997127.stgit@warthog.procyon.org.uk/Signed-off-by: David S. Miller <davem@davemloft.net>

Lorenzo Bianconi says:

====================

This series introduces XDP frags support. The mvneta driver is
the first to support these new "non-linear" xdp_{buff,frame}. Reviewers
please focus on how these new types of xdp_{buff,frame} packets
traverse the different layers and the layout design. It is on purpose
that BPF-helpers are kept simple, as we don't want to expose the
internal layout to allow later changes.

The main idea for the new XDP frags layout is to reuse the same
structure used for non-linear SKB. This rely on the "skb_shared_info"
struct at the end of the first buffer to link together subsequent
buffers. Keeping the layout compatible with SKBs is also done to ease
and speedup creating a SKB from an xdp_{buff,frame}.
Converting xdp_frame to SKB and deliver it to the network stack is shown
in patch 05/18 (e.g. cpumaps).

A frags bit (XDP_FLAGS_HAS_FRAGS) has been introduced in the flags
field of xdp_{buff,frame} structure to notify the bpf/network layer if
this is a non-linear xdp frame (XDP_FLAGS_HAS_FRAGS set) or not
(XDP_FLAGS_HAS_FRAGS not set).
The frags bit will be set by a xdp frags capable driver only
for non-linear frames maintaining the capability to receive linear frames
without any extra cost since the skb_shared_info structure at the end
of the first buffer will be initialized only if XDP_FLAGS_HAS_FRAGS bit
is set. Moreover the flags field in xdp_{buff,frame} will be reused even for
xdp rx csum offloading in future series.

Typical use cases for this series are:
- Jumbo-frames
- Packet header split (please see Google’s use-case @ NetDevConf 0x14, [0])
- TSO/GRO for XDP_REDIRECT

The three following ebpf helpers (and related selftests) has been introduced:
- bpf_xdp_load_bytes:
  This helper is provided as an easy way to load data from a xdp buffer. It
  can be used to load len bytes from offset from the frame associated to
  xdp_md, into the buffer pointed by buf.
- bpf_xdp_store_bytes:
  Store len bytes from buffer buf into the frame associated to xdp_md, at
  offset.
- bpf_xdp_get_buff_len:
  Return the total frame size (linear + paged parts)

bpf_xdp_adjust_tail and bpf_xdp_copy helpers have been modified to take into
account non-linear xdp frames.
Moreover, similar to skb_header_pointer, we introduced bpf_xdp_pointer utility
routine to return a pointer to a given position in the xdp_buff if the
requested area (offset + len) is contained in a contiguous memory area
otherwise it must be copied in a bounce buffer provided by the caller running
bpf_xdp_copy_buf().

BPF_F_XDP_HAS_FRAGS flag has been introduced to notify the kernel the
eBPF program fully support xdp frags.
SEC("xdp.frags"), SEC_DEF("xdp.frags/devmap") and SEC_DEF("xdp.frags/cpumap")
have been introduced to declare xdp frags support.
The NIC driver is expected to reject an eBPF program if it is running in
XDP frags mode and the program does not support XDP frags.
In the same way it is not possible to mix XDP frags and XDP legacy
programs in a CPUMAP/DEVMAP or tailcall a XDP frags/legacy program from
a legacy/frags one.

More info about the main idea behind this approach can be found here [1][2].

Changes since v22:
- remove leftover CHECK macro usage
- reintroduce SEC_XDP_FRAGS flag in sec_def_flags
- rename xdp multi_frags in xdp frags
- do not report xdp_frags support in fdinfo

Changes since v21:
- rename *_mb in *_frags: e.g:
  s/xdp_buff_is_mb/xdp_buff_has_frags
- rely on ASSERT_* and not on CHECK in
  bpf_xdp_load_bytes/bpf_xdp_store_bytes self-tests
- change new multi.frags SEC definitions to use the following schema:
  prog_type.prog_flags/attach_place
- get rid of unnecessary properties in new multi.frags SEC definitions
- rebase on top of bpf-next

Changes since v20:
- rebase to current bpf-next

Changes since v19:
- do not run deprecated bpf_prog_load()
- rely on skb_frag_size_add/skb_frag_size_sub in
  bpf_xdp_mb_increase_tail/bpf_xdp_mb_shrink_tail
- rely on sinfo->nr_frags in bpf_xdp_mb_shrink_tail to check if the frame has
  been shrunk to a single-buffer one
- allow XDP_REDIRECT of a xdp-mb frame into a CPUMAP

Changes since v18:
- fix bpf_xdp_copy_buf utility routine when we want to load/store data
  contained in frag<n>
- add a selftest for bpf_xdp_load_bytes/bpf_xdp_store_bytes when the caller
  accesses data contained in frag<n> and frag<n+1>

Changes since v17:
- rework bpf_xdp_copy to squash base and frag management
- remove unused variable in bpf_xdp_mb_shrink_tail()
- move bpf_xdp_copy_buf() out of bpf_xdp_pointer()
- add sanity check for len in bpf_xdp_pointer()
- remove EXPORT_SYMBOL for __xdp_return()
- introduce frag_size field in xdp_rxq_info to let the driver specify max value
  for xdp fragments. frag_size set to 0 means the tail increase of last the
  fragment is not supported.

Changes since v16:
- do not allow tailcalling a xdp multi-buffer/legacy program from a
  legacy/multi-buff one.
- do not allow mixing xdp multi-buffer and xdp legacy programs in a
  CPUMAP/DEVMAP
- add selftests for CPUMAP/DEVMAP xdp mb compatibility
- disable XDP_REDIRECT for xdp multi-buff for the moment
- set max offset value to 0xffff in bpf_xdp_pointer
- use ARG_PTR_TO_UNINIT_MEM and ARG_CONST_SIZE for arg3_type and arg4_type
  of bpf_xdp_store_bytes/bpf_xdp_load_bytes

Changes since v15:
- let the verifier check buf is not NULL in
  bpf_xdp_load_bytes/bpf_xdp_store_bytes helpers
- return an error if offset + length is over frame boundaries in
  bpf_xdp_pointer routine
- introduce BPF_F_XDP_MB flag for bpf_attr to notify the kernel the eBPF
  program fully supports xdp multi-buffer.
- reject a non XDP multi-buffer program if the driver is running in
  XDP multi-buffer mode.

Changes since v14:
- intrudce bpf_xdp_pointer utility routine and
  bpf_xdp_load_bytes/bpf_xdp_store_bytes helpers
- drop bpf_xdp_adjust_data helper
- drop xdp_frags_truesize in skb_shared_info
- explode bpf_xdp_mb_adjust_tail in bpf_xdp_mb_increase_tail and
  bpf_xdp_mb_shrink_tail

Changes since v13:
- use u32 for xdp_buff/xdp_frame flags field
- rename xdp_frags_tsize in xdp_frags_truesize
- fixed comments

Changes since v12:
- fix bpf_xdp_adjust_data helper for single-buffer use case
- return -EFAULT in bpf_xdp_adjust_{head,tail} in case the data pointers are not
  properly reset
- collect ACKs from John

Changes since v11:
- add missing static to bpf_xdp_get_buff_len_proto structure
- fix bpf_xdp_adjust_data helper when offset is smaller than linear area length.

Changes since v10:
- move xdp->data to the requested payload offset instead of to the beginning of
  the fragment in bpf_xdp_adjust_data()

Changes since v9:
- introduce bpf_xdp_adjust_data helper and related selftest
- add xdp_frags_size and xdp_frags_tsize fields in skb_shared_info
- introduce xdp_update_skb_shared_info utility routine in ordere to not reset
  frags array in skb_shared_info converting from a xdp_buff/xdp_frame to a skb
- simplify bpf_xdp_copy routine

Changes since v8:
- add proper dma unmapping if XDP_TX fails on mvneta for a xdp multi-buff
- switch back to skb_shared_info implementation from previous xdp_shared_info
  one
- avoid using a bietfield in xdp_buff/xdp_frame since it introduces performance
  regressions. Tested now on 10G NIC (ixgbe) to verify there are no performance
  penalties for regular codebase
- add bpf_xdp_get_buff_len helper and remove frame_length field in xdp ctx
- add data_len field in skb_shared_info struct
- introduce XDP_FLAGS_FRAGS_PF_MEMALLOC flag

Changes since v7:
- rebase on top of bpf-next
- fix sparse warnings
- improve comments for frame_length in include/net/xdp.h

Changes since v6:
- the main difference respect to previous versions is the new approach proposed
  by Eelco to pass full length of the packet to eBPF layer in XDP context
- reintroduce multi-buff support to eBPF kself-tests
- reintroduce multi-buff support to bpf_xdp_adjust_tail helper
- introduce multi-buffer support to bpf_xdp_copy helper
- rebase on top of bpf-next

Changes since v5:
- rebase on top of bpf-next
- initialize mb bit in xdp_init_buff() and drop per-driver initialization
- drop xdp->mb initialization in xdp_convert_zc_to_xdp_frame()
- postpone introduction of frame_length field in XDP ctx to another series
- minor changes

Changes since v4:
- rebase ontop of bpf-next
- introduce xdp_shared_info to build xdp multi-buff instead of using the
  skb_shared_info struct
- introduce frame_length in xdp ctx
- drop previous bpf helpers
- fix bpf_xdp_adjust_tail for xdp multi-buff
- introduce xdp multi-buff self-tests for bpf_xdp_adjust_tail
- fix xdp_return_frame_bulk for xdp multi-buff

Changes since v3:
- rebase ontop of bpf-next
- add patch 10/13 to copy back paged data from a xdp multi-buff frame to
  userspace buffer for xdp multi-buff selftests

Changes since v2:
- add throughput measurements
- drop bpf_xdp_adjust_mb_header bpf helper
- introduce selftest for xdp multibuffer
- addressed comments on bpf_xdp_get_frags_count
- introduce xdp multi-buff support to cpumaps

Changes since v1:
- Fix use-after-free in xdp_return_{buff/frame}
- Introduce bpf helpers
- Introduce xdp_mb sample program
- access skb_shared_info->nr_frags only on the last fragment

Changes since RFC:
- squash multi-buffer bit initialization in a single patch
- add mvneta non-linear XDP buff support for tx side

[0] https://netdevconf.info/0x14/session.html?talk-the-path-to-tcp-4k-mtu-and-rx-zerocopy
[1] https://github.com/xdp-project/xdp-project/blob/master/areas/core/xdp-multi-buffer01-design.org
[2] https://netdevconf.info/0x14/session.html?tutorial-add-XDP-support-to-a-NIC-driver (XDPmulti-buffers section)

Eelco Chaudron (3):
  bpf: add frags support to the bpf_xdp_adjust_tail() API
  bpf: add frags support to xdp copy helpers
  bpf: selftests: update xdp_adjust_tail selftest to include xdp frags

Lorenzo Bianconi (19):
  net: skbuff: add size metadata to skb_shared_info for xdp
  xdp: introduce flags field in xdp_buff/xdp_frame
  net: mvneta: update frags bit before passing the xdp buffer to eBPF
    layer
  net: mvneta: simplify mvneta_swbm_add_rx_fragment management
  net: xdp: add xdp_update_skb_shared_info utility routine
  net: marvell: rely on xdp_update_skb_shared_info utility routine
  xdp: add frags support to xdp_return_{buff/frame}
  net: mvneta: add frags support to XDP_TX
  bpf: introduce BPF_F_XDP_HAS_FRAGS flag in prog_flags loading the ebpf
    program
  net: mvneta: enable jumbo frames if the loaded XDP program support
    frags
  bpf: introduce bpf_xdp_get_buff_len helper
  bpf: move user_size out of bpf_test_init
  bpf: introduce frags support to bpf_prog_test_run_xdp()
  bpf: test_run: add xdp_shared_info pointer in bpf_test_finish
    signature
  libbpf: Add SEC name for xdp frags programs
  net: xdp: introduce bpf_xdp_pointer utility routine
  bpf: selftests: introduce bpf_xdp_{load,store}_bytes selftest
  bpf: selftests: add CPUMAP/DEVMAP selftests for xdp frags
  xdp: disable XDP_REDIRECT for xdp frags
====================
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

XDP_REDIRECT is not fully supported yet for xdp frags since not
all XDP capable drivers can map non-linear xdp_frame in ndo_xdp_xmit
so disable it for the moment.
Acked-by: Toke Hoiland-Jorgensen <toke@redhat.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://lore.kernel.org/r/0da25e117d0e2673f5d0ce6503393c55c6fb1be9.1642758637.git.lorenzo@kernel.orgSigned-off-by: Alexei Starovoitov <ast@kernel.org>

Verify compatibility checks attaching a XDP frags program to a
CPUMAP/DEVMAP
Acked-by: Toke Hoiland-Jorgensen <toke@redhat.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://lore.kernel.org/r/d94b4d35adc1e42c9ca5004e6b2cdfd75992304d.1642758637.git.lorenzo@kernel.orgSigned-off-by: Alexei Starovoitov <ast@kernel.org>

Introduce kernel selftest for new bpf_xdp_{load,store}_bytes helpers.
and bpf_xdp_pointer/bpf_xdp_copy_buf utility routines.
Acked-by: Toke Hoiland-Jorgensen <toke@redhat.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://lore.kernel.org/r/2c99ae663a5dcfbd9240b1d0489ad55dea4f4601.1642758637.git.lorenzo@kernel.orgSigned-off-by: Alexei Starovoitov <ast@kernel.org>

Similar to skb_header_pointer, introduce bpf_xdp_pointer utility routine
to return a pointer to a given position in the xdp_buff if the requested
area (offset + len) is contained in a contiguous memory area otherwise it
will be copied in a bounce buffer provided by the caller.
Similar to the tc counterpart, introduce the two following xdp helpers:
- bpf_xdp_load_bytes
- bpf_xdp_store_bytes
Reviewed-by: Eelco Chaudron <echaudro@redhat.com>
Acked-by: Toke Hoiland-Jorgensen <toke@redhat.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://lore.kernel.org/r/ab285c1efdd5b7a9d361348b1e7d3ef49f6382b3.1642758637.git.lorenzo@kernel.orgSigned-off-by: Alexei Starovoitov <ast@kernel.org>

The check for tail call map compatibility ensures that tail calls only
happen between maps of the same type. To ensure backwards compatibility for
XDP frags we need a similar type of check for cpumap and devmap
programs, so move the state from bpf_array_aux into bpf_map, add
xdp_has_frags to the check, and apply the same check to cpumap and devmap.
Acked-by: John Fastabend <john.fastabend@gmail.com>
Co-developed-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Toke Hoiland-Jorgensen <toke@redhat.com>
Link: https://lore.kernel.org/r/f19fd97c0328a39927f3ad03e1ca6b43fd53cdfd.1642758637.git.lorenzo@kernel.orgSigned-off-by: Alexei Starovoitov <ast@kernel.org>

Introduce support for the following SEC entries for XDP frags
property:
- SEC("xdp.frags")
- SEC("xdp.frags/devmap")
- SEC("xdp.frags/cpumap")
Acked-by: Toke Hoiland-Jorgensen <toke@redhat.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://lore.kernel.org/r/af23b6e4841c171ad1af01917839b77847a4bc27.1642758637.git.lorenzo@kernel.orgSigned-off-by: Alexei Starovoitov <ast@kernel.org>

This change adds test cases for the xdp frags scenarios when shrinking
and growing.
Acked-by: Toke Hoiland-Jorgensen <toke@redhat.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Co-developed-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Eelco Chaudron <echaudro@redhat.com>
Link: https://lore.kernel.org/r/d2e6a0ebc52db6f89e62b9befe045032e5e0a5fe.1642758637.git.lorenzo@kernel.orgSigned-off-by: Alexei Starovoitov <ast@kernel.org>

introduce xdp_shared_info pointer in bpf_test_finish signature in order
to copy back paged data from a xdp frags frame to userspace buffer
Acked-by: Toke Hoiland-Jorgensen <toke@redhat.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://lore.kernel.org/r/c803673798c786f915bcdd6c9338edaa9740d3d6.1642758637.git.lorenzo@kernel.orgSigned-off-by: Alexei Starovoitov <ast@kernel.org>

Introduce the capability to allocate a xdp frags in
bpf_prog_test_run_xdp routine. This is a preliminary patch to
introduce the selftests for new xdp frags ebpf helpers
Acked-by: Toke Hoiland-Jorgensen <toke@redhat.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://lore.kernel.org/r/b7c0e425a9287f00f601c4fc0de54738ec6ceeea.1642758637.git.lorenzo@kernel.orgSigned-off-by: Alexei Starovoitov <ast@kernel.org>

Rely on data_size_in in bpf_test_init routine signature. This is a
preliminary patch to introduce xdp frags selftest
Acked-by: Toke Hoiland-Jorgensen <toke@redhat.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://lore.kernel.org/r/6b48d38ed3d60240d7d6bb15e6fa7fabfac8dfb2.1642758637.git.lorenzo@kernel.orgSigned-off-by: Alexei Starovoitov <ast@kernel.org>

This patch adds support for frags for the following helpers:
  - bpf_xdp_output()
  - bpf_perf_event_output()
Acked-by: Toke Hoiland-Jorgensen <toke@redhat.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Eelco Chaudron <echaudro@redhat.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://lore.kernel.org/r/340b4a99cdc24337b40eaf8bb597f9f9e7b0373e.1642758637.git.lorenzo@kernel.orgSigned-off-by: Alexei Starovoitov <ast@kernel.org>

This change adds support for tail growing and shrinking for XDP frags.

When called on a non-linear packet with a grow request, it will work
on the last fragment of the packet. So the maximum grow size is the
last fragments tailroom, i.e. no new buffer will be allocated.
A XDP frags capable driver is expected to set frag_size in xdp_rxq_info
data structure to notify the XDP core the fragment size.
frag_size set to 0 is interpreted by the XDP core as tail growing is
not allowed.
Introduce __xdp_rxq_info_reg utility routine to initialize frag_size field.

When shrinking, it will work from the last fragment, all the way down to
the base buffer depending on the shrinking size. It's important to mention
that once you shrink down the fragment(s) are freed, so you can not grow
again to the original size.
Acked-by: Toke Hoiland-Jorgensen <toke@redhat.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Co-developed-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Eelco Chaudron <echaudro@redhat.com>
Link: https://lore.kernel.org/r/eabda3485dda4f2f158b477729337327e609461d.1642758637.git.lorenzo@kernel.orgSigned-off-by: Alexei Starovoitov <ast@kernel.org>

Introduce bpf_xdp_get_buff_len helper in order to return the xdp buffer
total size (linear and paged area)
Acked-by: Toke Hoiland-Jorgensen <toke@redhat.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://lore.kernel.org/r/aac9ac3504c84026cf66a3c71b7c5ae89bc991be.1642758637.git.lorenzo@kernel.orgSigned-off-by: Alexei Starovoitov <ast@kernel.org>

Enable the capability to receive jumbo frames even if the interface is
running in XDP mode if the loaded program declare to properly support
xdp frags. At same time reject a xdp program not supporting xdp frags
if the driver is running in xdp frags mode.
Acked-by: Toke Hoiland-Jorgensen <toke@redhat.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://lore.kernel.org/r/6909f81a3cbb8fb6b88e914752c26395771b882a.1642758637.git.lorenzo@kernel.orgSigned-off-by: Alexei Starovoitov <ast@kernel.org>