The set flag NFT_SET_EXPR provides a hint to the kernel that userspace
supports for multiple expressions per set element. In the same
direction, NFT_DYNSET_F_EXPR specifies that dynset expression defines
multiple expressions per set element.

This allows new userspace software with old kernels to bail out with
EOPNOTSUPP. This update is similar to ef516e8625dd ("netfilter:
nf_tables: reintroduce the NFT_SET_CONCAT flag"). The NFT_SET_EXPR flag
needs to be set on when the NFTA_SET_EXPRESSIONS attribute is specified.
The NFT_SET_EXPR flag is not set on with NFTA_SET_EXPR to retain
backward compatibility in old userspace binaries.

Fixes: 48b0ae046ee9 ("netfilter: nftables: netlink support for several set element expressions")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Pull networking updates from Jakub Kicinski:
 "Core:

   - support "prefer busy polling" NAPI operation mode, where we defer
     softirq for some time expecting applications to periodically busy
     poll

   - AF_XDP: improve efficiency by more batching and hindering the
     adjacency cache prefetcher

   - af_packet: make packet_fanout.arr size configurable up to 64K

   - tcp: optimize TCP zero copy receive in presence of partial or
     unaligned reads making zero copy a performance win for much smaller
     messages

   - XDP: add bulk APIs for returning / freeing frames

   - sched: support fragmenting IP packets as they come out of conntrack

   - net: allow virtual netdevs to forward UDP L4 and fraglist GSO skbs

  BPF:

   - BPF switch from crude rlimit-based to memcg-based memory accounting

   - BPF type format information for kernel modules and related tracing
     enhancements

   - BPF implement task local storage for BPF LSM

   - allow the FENTRY/FEXIT/RAW_TP tracing programs to use
     bpf_sk_storage

  Protocols:

   - mptcp: improve multiple xmit streams support, memory accounting and
     many smaller improvements

   - TLS: support CHACHA20-POLY1305 cipher

   - seg6: add support for SRv6 End.DT4/DT6 behavior

   - sctp: Implement RFC 6951: UDP Encapsulation of SCTP

   - ppp_generic: add ability to bridge channels directly

   - bridge: Connectivity Fault Management (CFM) support as is defined
     in IEEE 802.1Q section 12.14.

  Drivers:

   - mlx5: make use of the new auxiliary bus to organize the driver
     internals

   - mlx5: more accurate port TX timestamping support

   - mlxsw:
      - improve the efficiency of offloaded next hop updates by using
        the new nexthop object API
      - support blackhole nexthops
      - support IEEE 802.1ad (Q-in-Q) bridging

   - rtw88: major bluetooth co-existance improvements

   - iwlwifi: support new 6 GHz frequency band

   - ath11k: Fast Initial Link Setup (FILS)

   - mt7915: dual band concurrent (DBDC) support

   - net: ipa: add basic support for IPA v4.5

  Refactor:

   - a few pieces of in_interrupt() cleanup work from Sebastian Andrzej
     Siewior

   - phy: add support for shared interrupts; get rid of multiple driver
     APIs and have the drivers write a full IRQ handler, slight growth
     of driver code should be compensated by the simpler API which also
     allows shared IRQs

   - add common code for handling netdev per-cpu counters

   - move TX packet re-allocation from Ethernet switch tag drivers to a
     central place

   - improve efficiency and rename nla_strlcpy

   - number of W=1 warning cleanups as we now catch those in a patchwork
     build bot

  Old code removal:

   - wan: delete the DLCI / SDLA drivers

   - wimax: move to staging

   - wifi: remove old WDS wifi bridging support"

* tag 'net-next-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1922 commits)
  net: hns3: fix expression that is currently always true
  net: fix proc_fs init handling in af_packet and tls
  nfc: pn533: convert comma to semicolon
  af_vsock: Assign the vsock transport considering the vsock address flags
  af_vsock: Set VMADDR_FLAG_TO_HOST flag on the receive path
  vsock_addr: Check for supported flag values
  vm_sockets: Add VMADDR_FLAG_TO_HOST vsock flag
  vm_sockets: Add flags field in the vsock address data structure
  net: Disable NETIF_F_HW_TLS_TX when HW_CSUM is disabled
  tcp: Add logic to check for SYN w/ data in tcp_simple_retransmit
  net: mscc: ocelot: install MAC addresses in .ndo_set_rx_mode from process context
  nfc: s3fwrn5: Release the nfc firmware
  net: vxget: clean up sparse warnings
  mlxsw: spectrum_router: Use eXtended mezzanine to offload IPv4 router
  mlxsw: spectrum: Set KVH XLT cache mode for Spectrum2/3
  mlxsw: spectrum_router_xm: Introduce basic XM cache flushing
  mlxsw: reg: Add Router LPM Cache Enable Register
  mlxsw: reg: Add Router LPM Cache ML Delete Register
  mlxsw: spectrum_router_xm: Implement L-value tracking for M-index
  mlxsw: reg: Add XM Router M Table Register
  ...

and include <linux/const.h> in UAPI headers instead of <linux/kernel.h>.

The reason is to avoid indirect <linux/sysinfo.h> include when using
some network headers: <linux/netlink.h> or others -> <linux/kernel.h>
-> <linux/sysinfo.h>.

This indirect include causes on MUSL redefinition of struct sysinfo when
included both <sys/sysinfo.h> and some of UAPI headers:

    In file included from x86_64-buildroot-linux-musl/sysroot/usr/include/linux/kernel.h:5,
                     from x86_64-buildroot-linux-musl/sysroot/usr/include/linux/netlink.h:5,
                     from ../include/tst_netlink.h:14,
                     from tst_crypto.c:13:
    x86_64-buildroot-linux-musl/sysroot/usr/include/linux/sysinfo.h:8:8: error: redefinition of `struct sysinfo'
     struct sysinfo {
            ^~~~~~~
    In file included from ../include/tst_safe_macros.h:15,
                     from ../include/tst_test.h:93,
                     from tst_crypto.c:11:
    x86_64-buildroot-linux-musl/sysroot/usr/include/sys/sysinfo.h:10:8: note: originally defined here

Link: https://lkml.kernel.org/r/20201015190013.8901-1-petr.vorel@gmail.com
Signed-off-by: Petr Vorel <petr.vorel@gmail.com>
Suggested-by: Rich Felker <dalias@aerifal.cx>
Acked-by: Rich Felker <dalias@libc.org>
Cc: Peter Korsgaard <peter@korsgaard.com>
Cc: Baruch Siach <baruch@tkos.co.il>
Cc: Florian Weimer <fweimer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This patch adds three new netlink attributes to encapsulate a list of
expressions per set elements:

- NFTA_SET_EXPRESSIONS: this attribute provides the set definition in
  terms of expressions. New set elements get attached the list of
  expressions that is specified by this new netlink attribute.
- NFTA_SET_ELEM_EXPRESSIONS: this attribute allows users to restore (or
  initialize) the stateful information of set elements when adding an
  element to the set.
- NFTA_DYNSET_EXPRESSIONS: this attribute specifies the list of
  expressions that the set element gets when it is inserted from the
  packet path.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

It makes possible to reproduce exactly the same set after a save/restore.

Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

The parameter defines the upper limit in any hash bucket at adding new entries
from userspace - if the limit would be exceeded, ipset doubles the hash size
and rehashes. It means the set may consume more memory but gives faster
evaluation at matching in the set.

Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

nftables payload statements are used to mangle SCTP headers, but they can
only replace the Internet Checksum. As a consequence, nftables rules that
mangle sport/dport/vtag in SCTP headers potentially generate packets that
are discarded by the receiver, unless the CRC-32C is "offloaded" (e.g the
rule mangles a skb having 'ip_summed' equal to 'CHECKSUM_PARTIAL'.

Fix this extending uAPI definitions and L4 checksum update function, in a
way that userspace programs (e.g. nft) can instruct the kernel to compute
CRC-32C in SCTP headers. Also ensure that LIBCRC32C is built if NF_TABLES
is 'y' or 'm' in the kernel build configuration.

Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Enables storing userdata for nft_chain. Field udata points to user data
and udlen stores its length.

Adds new attribute flag NFTA_CHAIN_USERDATA.

Signed-off-by: Jose M. Guisado Gomez <guigom@riseup.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Pablo Neira Ayuso says:

====================
Netfilter updates for net-next

The following patchset contains Netfilter updates for net-next:

1) Rewrite inner header IPv6 in ICMPv6 messages in ip6t_NPT,
   from Michael Zhou.

2) do_ip_vs_set_ctl() dereferences uninitialized value,
   from Peilin Ye.

3) Support for userdata in tables, from Jose M. Guisado.

4) Do not increment ct error and invalid stats at the same time,
   from Florian Westphal.

5) Remove ct ignore stats, also from Florian.

6) Add ct stats for clash resolution, from Florian Westphal.

7) Bump reference counter bump on ct clash resolution only,
   this is safe because bucket lock is held, again from Florian.

8) Use ip_is_fragment() in xt_HMARK, from YueHaibing.

9) Add wildcard support for nft_socket, from Balazs Scheidler.

10) Remove superfluous IPVS dependency on iptables, from
    Yaroslav Bolyukin.

11) Remove unused definition in ebt_stp, from Wang Hai.

12) Replace CONFIG_NFT_CHAIN_NAT_{IPV4,IPV6} by CONFIG_NFT_NAT
    in selftests/net, from Fabian Frederick.

13) Add userdata support for nft_object, from Jose M. Guisado.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

Enables storing userdata for nft_object. Initially this will store an
optional comment but can be extended in the future as needed.

Adds new attribute NFTA_OBJ_USERDATA to nft_object.

Signed-off-by: Jose M. Guisado Gomez <guigom@riseup.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>