Commit Graph

6512 Commits

Author SHA1 Message Date
Jiri Pirko
742b8cceaa drop_monitor: extend by passing cookie from driver
If driver passed along the cookie, push it through Netlink.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-25 11:05:54 -08:00
Jiri Pirko
85b0589ede devlink: add trap metadata type for cookie
Allow driver to indicate cookie metadata for registered traps.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-25 11:05:54 -08:00
David S. Miller
3b3e808cd8 Merge tag 'mac80211-next-for-net-next-2020-02-24' of git://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211-next
Johannes Berg says:

====================
A new set of changes:
 * lots of small documentation fixes, from Jérôme Pouiller
 * beacon protection (BIGTK) support from Jouni Malinen
 * some initial code for TID configuration, from Tamizh chelvam
 * I reverted some new API before it's actually used, because
   it's wrong to mix controlled port and preauth
 * a few other cleanups/fixes
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-24 15:41:54 -08:00
Martin Varghese
4b5f67232d net: Special handling for IP & MPLS.
Special handling is needed in bareudp module for IP & MPLS as they
support more than one ethertypes.

MPLS has 2 ethertypes. 0x8847 for MPLS unicast and 0x8848 for MPLS multicast.
While decapsulating MPLS packet from UDP packet the tunnel destination IP
address is checked to determine the ethertype. The ethertype of the packet
will be set to 0x8848 if the  tunnel destination IP address is a multicast
IP address. The ethertype of the packet will be set to 0x8847 if the
tunnel destination IP address is a unicast IP address.

IP has 2 ethertypes.0x0800 for IPV4 and 0x86dd for IPv6. The version
field of the IP header tunnelled will be checked to determine the ethertype.

This special handling to tunnel additional ethertypes will be disabled
by default and can be enabled using a flag called multiproto. This flag can
be used only with ethertypes 0x8847 and 0x0800.

Signed-off-by: Martin Varghese <martin.varghese@nokia.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-24 13:31:42 -08:00
Martin Varghese
571912c69f net: UDP tunnel encapsulation module for tunnelling different protocols like MPLS, IP, NSH etc.
The Bareudp tunnel module provides a generic L3 encapsulation
tunnelling module for tunnelling different protocols like MPLS,
IP,NSH etc inside a UDP tunnel.

Signed-off-by: Martin Varghese <martin.varghese@nokia.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-24 13:31:42 -08:00
Tamizh chelvam
04f7d142f5 nl80211: Add support to configure TID specific RTSCTS configuration
This patch adds support to configure per TID RTSCTS control
configuration to enable/disable through the
NL80211_TID_CONFIG_ATTR_RTSCTS_CTRL attribute.

Signed-off-by: Tamizh chelvam <tamizhr@codeaurora.org>
Link: https://lore.kernel.org/r/1579506687-18296-5-git-send-email-tamizhr@codeaurora.org
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2020-02-24 13:56:57 +01:00
Tamizh chelvam
ade274b23e nl80211: Add support to configure TID specific AMPDU configuration
This patch adds support to configure per TID AMPDU control
configuration to enable/disable aggregation through the
NL80211_TID_CONFIG_ATTR_AMPDU_CTRL attribute.

Signed-off-by: Tamizh chelvam <tamizhr@codeaurora.org>
Link: https://lore.kernel.org/r/1579506687-18296-4-git-send-email-tamizhr@codeaurora.org
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2020-02-24 13:56:49 +01:00
Tamizh chelvam
6a21d16c4d nl80211: Add support to configure TID specific retry configuration
This patch adds support to configure per TID retry configuration
through the NL80211_TID_CONFIG_ATTR_RETRY_SHORT and
NL80211_TID_CONFIG_ATTR_RETRY_LONG attributes. This TID specific
retry configuration will have more precedence than phy level
configuration.

Signed-off-by: Tamizh chelvam <tamizhr@codeaurora.org>
Link: https://lore.kernel.org/r/1579506687-18296-3-git-send-email-tamizhr@codeaurora.org
[rebase completely on top of my previous API changes]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2020-02-24 13:48:54 +01:00
Johannes Berg
3710a8a628 nl80211: modify TID-config API
Make some changes to the TID-config API:
 * use u16 in nl80211 (only, and restrict to using 8 bits for now),
   to avoid issues in the future if we ever want to use higher TIDs.
 * reject empty TIDs mask (via netlink policy)
 * change feature advertising to not use extended feature flags but
   have own mechanism for this, which simplifies the code
 * fix all variable names from 'tid' to 'tids' since it's a mask
 * change to cfg80211_ name prefixes, not ieee80211_
 * fix some minor docs/spelling things.

Change-Id: Ia234d464b3f914cdeab82f540e018855be580dce
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2020-02-24 12:01:10 +01:00
Tamizh chelvam
77f576deaa nl80211: Add NL command to support TID speicific configurations
Add the new NL80211_CMD_SET_TID_CONFIG command to support
data TID specific configuration. Per TID configuration is
passed in the nested NL80211_ATTR_TID_CONFIG attribute.

This patch adds support to configure per TID noack policy
through the NL80211_TID_CONFIG_ATTR_NOACK attribute.

Signed-off-by: Tamizh chelvam <tamizhr@codeaurora.org>
Link: https://lore.kernel.org/r/1579506687-18296-2-git-send-email-tamizhr@codeaurora.org
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2020-02-24 11:15:25 +01:00
Jouni Malinen
56be393fa8 cfg80211: Support key configuration for Beacon protection (BIGTK)
IEEE P802.11-REVmd/D3.0 adds support for protecting Beacon frames using
a new set of keys (BIGTK; key index 6..7) similarly to the way
group-addressed Robust Management frames are protected (IGTK; key index
4..5). Extend cfg80211 and nl80211 to allow the new BIGTK to be
configured. Add an extended feature flag to indicate driver support for
the new key index values to avoid array overflows in driver
implementations and also to indicate to user space when this
functionality is available.

Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
Link: https://lore.kernel.org/r/20200222132548.20835-2-jouni@codeaurora.org
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2020-02-24 10:35:48 +01:00
Johannes Berg
8d74a623cc Revert "nl80211: add src and dst addr attributes for control port tx/rx"
This reverts commit 8c3ed7aa2b.

As Jouni points out, there's really no need for this, since the
RSN pre-authentication frames are normal data frames, not port
control frames (locally).

We can still revert this now since it hasn't actually gone beyond
-next.

Fixes: 8c3ed7aa2b ("nl80211: add src and dst addr attributes for control port tx/rx")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Link: https://lore.kernel.org/r/20200224101910.b746e263287a.I9eb15d6895515179d50964dec3550c9dc784bb93@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2020-02-24 10:22:02 +01:00
David S. Miller
b105e8e281 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
pull-request: bpf-next 2020-02-21

The following pull-request contains BPF updates for your *net-next* tree.

We've added 25 non-merge commits during the last 4 day(s) which contain
a total of 33 files changed, 2433 insertions(+), 161 deletions(-).

The main changes are:

1) Allow for adding TCP listen sockets into sock_map/hash so they can be used
   with reuseport BPF programs, from Jakub Sitnicki.

2) Add a new bpf_program__set_attach_target() helper for adding libbpf support
   to specify the tracepoint/function dynamically, from Eelco Chaudron.

3) Add bpf_read_branch_records() BPF helper which helps use cases like profile
   guided optimizations, from Daniel Xu.

4) Enable bpf_perf_event_read_value() in all tracing programs, from Song Liu.

5) Relax BTF mandatory check if only used for libbpf itself e.g. to process
   BTF defined maps, from Andrii Nakryiko.

6) Move BPF selftests -mcpu compilation attribute from 'probe' to 'v3' as it has
   been observed that former fails in envs with low memlock, from Yonghong Song.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-21 15:22:45 -08:00
David S. Miller
e65ee2fb54 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Conflict resolution of ice_virtchnl_pf.c based upon work by
Stephen Rothwell.

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-21 13:39:34 -08:00
Linus Torvalds
cee853e825 Merge tag 'usb-5.6-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb
Pull USB/Thunderbolt fixes from Greg KH:
 "Here are a number of small USB driver fixes for 5.6-rc3.

  Included in here are:
  - MAINTAINER file updates
  - USB gadget driver fixes
  - usb core quirk additions and fixes for regressions
  - xhci driver fixes
  - usb serial driver id additions and fixes
  - thunderbolt bugfix

  Thunderbolt patches come in through here now that USB4 is really
  thunderbolt.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'usb-5.6-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (34 commits)
  USB: misc: iowarrior: add support for the 100 device
  thunderbolt: Prevent crash if non-active NVMem file is read
  usb: gadget: udc-xilinx: Fix xudc_stop() kernel-doc format
  USB: misc: iowarrior: add support for the 28 and 28L devices
  USB: misc: iowarrior: add support for 2 OEMed devices
  USB: Fix novation SourceControl XL after suspend
  xhci: Fix memory leak when caching protocol extended capability PSI tables - take 2
  Revert "xhci: Fix memory leak when caching protocol extended capability PSI tables"
  MAINTAINERS: Sort entries in database for THUNDERBOLT
  usb: dwc3: debug: fix string position formatting mixup with ret and len
  usb: gadget: serial: fix Tx stall after buffer overflow
  usb: gadget: ffs: ffs_aio_cancel(): Save/restore IRQ flags
  usb: dwc2: Fix SET/CLEAR_FEATURE and GET_STATUS flows
  usb: dwc2: Fix in ISOC request length checking
  usb: gadget: composite: Support more than 500mA MaxPower
  usb: gadget: composite: Fix bMaxPower for SuperSpeedPlus
  usb: gadget: u_audio: Fix high-speed max packet size
  usb: dwc3: gadget: Check for IOC/LST bit in TRB->ctrl fields
  USB: core: clean up endpoint-descriptor parsing
  USB: quirks: blacklist duplicate ep on Sound Devices USBPre2
  ...
2020-02-21 12:44:53 -08:00
Linus Torvalds
3dc55dba67 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from David Miller:

 1) Limit xt_hashlimit hash table size to avoid OOM or hung tasks, from
    Cong Wang.

 2) Fix deadlock in xsk by publishing global consumer pointers when NAPI
    is finished, from Magnus Karlsson.

 3) Set table field properly to RT_TABLE_COMPAT when necessary, from
    Jethro Beekman.

 4) NLA_STRING attributes are not necessary NULL terminated, deal wiht
    that in IFLA_ALT_IFNAME. From Eric Dumazet.

 5) Fix checksum handling in atlantic driver, from Dmitry Bezrukov.

 6) Handle mtu==0 devices properly in wireguard, from Jason A.
    Donenfeld.

 7) Fix several lockdep warnings in bonding, from Taehee Yoo.

 8) Fix cls_flower port blocking, from Jason Baron.

 9) Sanitize internal map names in libbpf, from Toke Høiland-Jørgensen.

10) Fix RDMA race in qede driver, from Michal Kalderon.

11) Fix several false lockdep warnings by adding conditions to
    list_for_each_entry_rcu(), from Madhuparna Bhowmik.

12) Fix sleep in atomic in mlx5 driver, from Huy Nguyen.

13) Fix potential deadlock in bpf_map_do_batch(), from Yonghong Song.

14) Hey, variables declared in switch statement before any case
    statements are not initialized. I learn something every day. Get
    rids of this stuff in several parts of the networking, from Kees
    Cook.

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (99 commits)
  bnxt_en: Issue PCIe FLR in kdump kernel to cleanup pending DMAs.
  bnxt_en: Improve device shutdown method.
  net: netlink: cap max groups which will be considered in netlink_bind()
  net: thunderx: workaround BGX TX Underflow issue
  ionic: fix fw_status read
  net: disable BRIDGE_NETFILTER by default
  net: macb: Properly handle phylink on at91rm9200
  s390/qeth: fix off-by-one in RX copybreak check
  s390/qeth: don't warn for napi with 0 budget
  s390/qeth: vnicc Fix EOPNOTSUPP precedence
  openvswitch: Distribute switch variables for initialization
  net: ip6_gre: Distribute switch variables for initialization
  net: core: Distribute switch variables for initialization
  udp: rehash on disconnect
  net/tls: Fix to avoid gettig invalid tls record
  bpf: Fix a potential deadlock with bpf_map_do_batch
  bpf: Do not grab the bucket spinlock by default on htab batch ops
  ice: Wait for VF to be reset/ready before configuration
  ice: Don't tell the OS that link is going down
  ice: Don't reject odd values of usecs set by user
  ...
2020-02-21 11:59:51 -08:00
Christian Borntraeger
467d12f5c7 include/uapi/linux/swab.h: fix userspace breakage, use __BITS_PER_LONG for swap
QEMU has a funny new build error message when I use the upstream kernel
headers:

      CC      block/file-posix.o
    In file included from /home/cborntra/REPOS/qemu/include/qemu/timer.h:4,
                     from /home/cborntra/REPOS/qemu/include/qemu/timed-average.h:29,
                     from /home/cborntra/REPOS/qemu/include/block/accounting.h:28,
                     from /home/cborntra/REPOS/qemu/include/block/block_int.h:27,
                     from /home/cborntra/REPOS/qemu/block/file-posix.c:30:
    /usr/include/linux/swab.h: In function `__swab':
    /home/cborntra/REPOS/qemu/include/qemu/bitops.h:20:34: error: "sizeof" is not defined, evaluates to 0 [-Werror=undef]
       20 | #define BITS_PER_LONG           (sizeof (unsigned long) * BITS_PER_BYTE)
          |                                  ^~~~~~
    /home/cborntra/REPOS/qemu/include/qemu/bitops.h:20:41: error: missing binary operator before token "("
       20 | #define BITS_PER_LONG           (sizeof (unsigned long) * BITS_PER_BYTE)
          |                                         ^
    cc1: all warnings being treated as errors
    make: *** [/home/cborntra/REPOS/qemu/rules.mak:69: block/file-posix.o] Error 1
    rm tests/qemu-iotests/socket_scm_helper.o

This was triggered by commit d5767057c9 ("uapi: rename ext2_swab() to
swab() and share globally in swab.h").  That patch is doing

  #include <asm/bitsperlong.h>

but it uses BITS_PER_LONG.

The kernel file asm/bitsperlong.h provide only __BITS_PER_LONG.

Let us use the __ variant in swap.h

Link: http://lkml.kernel.org/r/20200213142147.17604-1-borntraeger@de.ibm.com
Fixes: d5767057c9 ("uapi: rename ext2_swab() to swab() and share globally in swab.h")
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Yury Norov <yury.norov@gmail.com>
Cc: Allison Randal <allison@lohutok.net>
Cc: Joe Perches <joe@perches.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: William Breathitt Gray <vilhelm.gray@gmail.com>
Cc: Torsten Hilbrich <torsten.hilbrich@secunet.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-02-21 11:22:15 -08:00
Arnd Bergmann
c766d1472c y2038: hide timeval/timespec/itimerval/itimerspec types
There are no in-kernel users remaining, but there may still be users that
include linux/time.h instead of sys/time.h from user space, so leave the
types available to user space while hiding them from kernel space.

Only the __kernel_old_* versions of these types remain now.

Link: http://lkml.kernel.org/r/20200110154232.4104492-4-arnd@arndb.de
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Deepa Dinamani <deepa.kernel@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-02-21 11:22:15 -08:00
David S. Miller
41f57cfde1 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Alexei Starovoitov says:

====================
pull-request: bpf 2020-02-19

The following pull-request contains BPF updates for your *net* tree.

We've added 10 non-merge commits during the last 10 day(s) which contain
a total of 10 files changed, 93 insertions(+), 31 deletions(-).

The main changes are:

1) batched bpf hashtab fixes from Brian and Yonghong.

2) various selftests and libbpf fixes.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-19 16:42:35 -08:00
Daniel Xu
fff7b64355 bpf: Add bpf_read_branch_records() helper
Branch records are a CPU feature that can be configured to record
certain branches that are taken during code execution. This data is
particularly interesting for profile guided optimizations. perf has had
branch record support for a while but the data collection can be a bit
coarse grained.

We (Facebook) have seen in experiments that associating metadata with
branch records can improve results (after postprocessing). We generally
use bpf_probe_read_*() to get metadata out of userspace. That's why bpf
support for branch records is useful.

Aside from this particular use case, having branch data available to bpf
progs can be useful to get stack traces out of userspace applications
that omit frame pointers.

Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200218030432.4600-2-dxu@dxuuu.xyz
2020-02-19 14:37:36 -08:00
Aya Levin
f623e59705 ethtool: Add support for low latency RS FEC
Add support for low latency Reed Solomon FEC as LLRS.

The LL-FEC is defined by the 25G/50G ethernet consortium,
in the document titled "Low Latency Reed Solomon Forward Error Correction"

Signed-off-by: Aya Levin <ayal@mellanox.com>
Reviewed-by: Eran Ben Elisha <eranbe@mellanox.com>
CC: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
2020-02-18 19:17:31 -08:00
David S. Miller
7c8c1697c7 Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf
Pablo Neira Ayuso says:

====================
Netfilter fixes for net

This batch contains Netfilter fixes for net:

1) Restrict hashlimit size to 1048576, from Cong Wang.

2) Check for offload flags from nf_flow_table_offload_setup(),
   this fixes a crash in case the hardware offload is disabled.
   From Florian Westphal.

3) Three preparation patches to extend the conntrack clash resolution,
   from Florian.

4) Extend clash resolution to deal with DNS packets from the same flow
   racing to set up the NAT configuration.

5) Small documentation fix in pipapo, from Stefano Brivio.

6) Remove misleading unlikely() from pipapo_refill(), also from Stefano.

7) Reduce hashlimit mutex scope, from Cong Wang. This patch is actually
   triggering another problem, still under discussion, another patch to
   fix this will follow up.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-18 15:44:13 -08:00
Toke Høiland-Jørgensen
f25975f42f bpf, uapi: Remove text about bpf_redirect_map() giving higher performance
The performance of bpf_redirect() is now roughly the same as that of
bpf_redirect_map(). However, David Ahern pointed out that the header file
has not been updated to reflect this, and still says that a significant
performance increase is possible when using bpf_redirect_map(). Remove this
text from the bpf_redirect_map() description, and reword the description in
bpf_redirect() slightly. Also fix the 'Return' section of the
bpf_redirect_map() documentation.

Fixes: 1d233886dd ("xdp: Use bulking for non-map XDP_REDIRECT and consolidate code paths")
Reported-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20200218130334.29889-1-toke@redhat.com
2020-02-18 15:31:31 +01:00
Florian Westphal
6a757c07e5 netfilter: conntrack: allow insertion of clashing entries
This patch further relaxes the need to drop an skb due to a clash with
an existing conntrack entry.

Current clash resolution handles the case where the clash occurs between
two identical entries (distinct nf_conn objects with same tuples), i.e.:

                    Original                        Reply
existing: 10.2.3.4:42 -> 10.8.8.8:53      10.2.3.4:42 <- 10.0.0.6:5353
clashing: 10.2.3.4:42 -> 10.8.8.8:53      10.2.3.4:42 <- 10.0.0.6:5353

... existing handling will discard the unconfirmed clashing entry and
makes skb->_nfct point to the existing one.  The skb can then be
processed normally just as if the clash would not have existed in the
first place.

For other clashes, the skb needs to be dropped.
This frequently happens with DNS resolvers that send A and AAAA queries
back-to-back when NAT rules are present that cause packets to get
different DNAT transformations applied, for example:

-m statistics --mode random ... -j DNAT --dnat-to 10.0.0.6:5353
-m statistics --mode random ... -j DNAT --dnat-to 10.0.0.7:5353

In this case the A or AAAA query is dropped which incurs a costly
delay during name resolution.

This patch also allows this collision type:
                       Original                   Reply
existing: 10.2.3.4:42 -> 10.8.8.8:53      10.2.3.4:42 <- 10.0.0.6:5353
clashing: 10.2.3.4:42 -> 10.8.8.8:53      10.2.3.4:42 <- 10.0.0.7:5353

In this case, clash is in original direction -- the reply direction
is still unique.

The change makes it so that when the 2nd colliding packet is received,
the clashing conntrack is tagged with new IPS_NAT_CLASH_BIT, gets a fixed
1 second timeout and is inserted in the reply direction only.

The entry is hidden from 'conntrack -L', it will time out quickly
and it can be early dropped because it will never progress to the
ASSURED state.

To avoid special-casing the delete code path to special case
the ORIGINAL hlist_nulls node, a new helper, "hlist_nulls_add_fake", is
added so hlist_nulls_del() will work.

Example:

      CPU A:                               CPU B:
1.  10.2.3.4:42 -> 10.8.8.8:53 (A)
2.                                         10.2.3.4:42 -> 10.8.8.8:53 (AAAA)
3.  Apply DNAT, reply changed to 10.0.0.6
4.                                         10.2.3.4:42 -> 10.8.8.8:53 (AAAA)
5.                                         Apply DNAT, reply changed to 10.0.0.7
6. confirm/commit to conntrack table, no collisions
7.                                         commit clashing entry

Reply comes in:

10.2.3.4:42 <- 10.0.0.6:5353 (A)
 -> Finds a conntrack, DNAT is reversed & packet forwarded to 10.2.3.4:42
10.2.3.4:42 <- 10.0.0.7:5353 (AAAA)
 -> Finds a conntrack, DNAT is reversed & packet forwarded to 10.2.3.4:42
    The conntrack entry is deleted from table, as it has the NAT_CLASH
    bit set.

In case of a retransmit from ORIGINAL dir, all further packets will get
the DNAT transformation to 10.0.0.6.

I tried to come up with other solutions but they all have worse
problems.

Alternatives considered were:
1.  Confirm ct entries at allocation time, not in postrouting.
 a. will cause uneccesarry work when the skb that creates the
    conntrack is dropped by ruleset.
 b. in case nat is applied, ct entry would need to be moved in
    the table, which requires another spinlock pair to be taken.
 c. breaks the 'unconfirmed entry is private to cpu' assumption:
    we would need to guard all nfct->ext allocation requests with
    ct->lock spinlock.

2. Make the unconfirmed list a hash table instead of a pcpu list.
   Shares drawback c) of the first alternative.

3. Document this is expected and force users to rearrange their
   ruleset (e.g. by using "-m cluster" instead of "-m statistics").
   nft has the 'jhash' expression which can be used instead of 'numgen'.

   Major drawback: doesn't fix what I consider a bug, not very realistic
   and I believe its reasonable to have the existing rulesets to 'just
   work'.

4. Document this is expected and force users to steer problematic
   packets to the same CPU -- this would serialize the "allocate new
   conntrack entry/nat table evaluation/perform nat/confirm entry", so
   no race can occur.  Similar drawback to 3.

Another advantage of this patch compared to 1) and 2) is that there are
no changes to the hot path; things are handled in the udp tracker and
the clash resolution path.

Cc: rcu@vger.kernel.org
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2020-02-17 10:55:14 +01:00
Matteo Croce
744676e777 openvswitch: add TTL decrement action
New action to decrement TTL instead of setting it to a fixed value.
This action will decrement the TTL and, in case of expired TTL, drop it
or execute an action passed via a nested attribute.
The default TTL expired action is to drop the packet.

Supports both IPv4 and IPv6 via the ttl and hop_limit fields, respectively.

Tested with a corresponding change in the userspace:

    # ovs-dpctl dump-flows
    in_port(2),eth(),eth_type(0x0800), packets:0, bytes:0, used:never, actions:dec_ttl{ttl<=1 action:(drop)},1
    in_port(1),eth(),eth_type(0x0800), packets:0, bytes:0, used:never, actions:dec_ttl{ttl<=1 action:(drop)},2
    in_port(1),eth(),eth_type(0x0806), packets:0, bytes:0, used:never, actions:2
    in_port(2),eth(),eth_type(0x0806), packets:0, bytes:0, used:never, actions:1

    # ping -c1 192.168.0.2 -t 42
    IP (tos 0x0, ttl 41, id 61647, offset 0, flags [DF], proto ICMP (1), length 84)
        192.168.0.1 > 192.168.0.2: ICMP echo request, id 386, seq 1, length 64
    # ping -c1 192.168.0.2 -t 120
    IP (tos 0x0, ttl 119, id 62070, offset 0, flags [DF], proto ICMP (1), length 84)
        192.168.0.1 > 192.168.0.2: ICMP echo request, id 388, seq 1, length 64
    # ping -c1 192.168.0.2 -t 1
    #

Co-developed-by: Bindiya Kurle <bindiyakurle@gmail.com>
Signed-off-by: Bindiya Kurle <bindiyakurle@gmail.com>
Signed-off-by: Matteo Croce <mcroce@redhat.com>
Acked-by: Pravin B Shelar <pshelar@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-16 19:34:44 -08:00