Pablo Neira Ayuso says:
====================
Netfilter updates for net-next
The following patchset contains Netfilter updates for net-next. This
includes one patch to update ovs and act_ct to use nf_ct_put() instead
of nf_conntrack_put().
1) Add netns_tracker to nfnetlink_log and masquerade, from Eric Dumazet.
2) Remove redundant rcu read-size lock in nf_tables packet path.
3) Replace BUG() by WARN_ON_ONCE() in nft_payload.
4) Consolidate rule verdict tracing.
5) Replace WARN_ON() by WARN_ON_ONCE() in nf_tables core.
6) Make counter support built-in in nf_tables.
7) Add new field to conntrack object to identify locally generated
traffic, from Florian Westphal.
8) Prevent NAT from shadowing well-known ports, from Florian Westphal.
9) Merge nf_flow_table_{ipv4,ipv6} into nf_flow_table_inet, also from
Florian.
10) Remove redundant pointer in nft_pipapo AVX2 support, from Colin Ian King.
11) Replace opencoded max() in conntrack, from Jiapeng Chong.
12) Update conntrack to use refcount_t API, from Florian Westphal.
13) Move ip_ct_attach indirection into the nf_ct_hook structure.
14) Constify several pointer object in the netfilter codebase,
from Florian Westphal.
15) Tree-wide replacement of nf_conntrack_put() by nf_ct_put(), also
from Florian.
16) Fix egress splat due to incorrect rcu notation, from Florian.
17) Move stateful fields of connlimit, last, quota, numgen and limit
out of the expression data area.
18) Build a blob to represent the ruleset in nf_tables, this is a
requirement of the new register tracking infrastructure.
19) Add NFT_REG32_NUM to define the maximum number of 32-bit registers.
20) Add register tracking infrastructure to skip redundant
store-to-register operations, this includes support for payload,
meta and bitwise expresssions.
* git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next: (32 commits)
netfilter: nft_meta: cancel register tracking after meta update
netfilter: nft_payload: cancel register tracking after payload update
netfilter: nft_bitwise: track register operations
netfilter: nft_meta: track register operations
netfilter: nft_payload: track register operations
netfilter: nf_tables: add register tracking infrastructure
netfilter: nf_tables: add NFT_REG32_NUM
netfilter: nf_tables: add rule blob layout
netfilter: nft_limit: move stateful fields out of expression data
netfilter: nft_limit: rename stateful structure
netfilter: nft_numgen: move stateful fields out of expression data
netfilter: nft_quota: move stateful fields out of expression data
netfilter: nft_last: move stateful fields out of expression data
netfilter: nft_connlimit: move stateful fields out of expression data
netfilter: egress: avoid a lockdep splat
net: prefer nf_ct_put instead of nf_conntrack_put
netfilter: conntrack: avoid useless indirection during conntrack destruction
netfilter: make function op structures const
netfilter: core: move ip_ct_attach indirection to struct nf_ct_hook
netfilter: conntrack: convert to refcount_t api
...
====================
Link: https://lore.kernel.org/r/20220109231640.104123-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Its the same as nf_conntrack_put(), but without the
need for an indirect call. The downside is a module dependency on
nf_conntrack, but all of these already depend on conntrack anyway.
Cc: Paul Blakey <paulb@mellanox.com>
Cc: dev@openvswitch.org
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Convert nf_conn reference counting from atomic_t to refcount_t based api.
refcount_t api provides more runtime sanity checks and will warn on
certain constructs, e.g. refcount_inc() on a zero reference count, which
usually indicates use-after-free.
For this reason template allocation is changed to init the refcount to
1, the subsequenct add operations are removed.
Likewise, init_conntrack() is changed to set the initial refcount to 1
instead refcount_inc().
This is safe because the new entry is not (yet) visible to other cpus.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
To give drivers the originating device information for optimized
connection tracking offload, fill in act ct extension with
ifindex from skb.
Signed-off-by: Paul Blakey <paulb@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Zone id is not restored if we passed ct and ct rejected the connection,
as there is no ct info on the skb.
Save the zone from tc skb cb to tc skb extension and pass it on to
ovs, use that info to restore the zone id for invalid connections.
Fixes: d29334c15d ("net/sched: act_api: fix miss set post_ct for ovs after do conntrack in act_ct")
Signed-off-by: Paul Blakey <paulb@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The 'if (dev)' statement already move into dev_{put , hold}, so remove
redundant if statements.
Signed-off-by: Xu Wang <vulab@iscas.ac.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>
nr_free_buffer_pages could be exposed through mm.h instead of swap.h.
The advantage of this change is that it can reduce the obsolete
includes. For example, net/ipv4/tcp.c wouldn't need swap.h any more
since it has already included mm.h. Similarly, after checking all the
other files, it comes that tcp.c, udp.c meter.c ,... follow the same
rule, so these files can have swap.h removed too.
Moreover, after preprocessing all the files that use
nr_free_buffer_pages, it turns out that those files have already
included mm.h.Thus, we can move nr_free_buffer_pages from swap.h to mm.h
safely. This change will not affect the compilation of other files.
Link: https://lkml.kernel.org/r/20210912133640.1624-1-liumh1@shanghaitech.edu.cn
Signed-off-by: Mianhan Liu <liumh1@shanghaitech.edu.cn>
Cc: Jakub Kicinski <kuba@kernel.org>
CC: Ulf Hansson <ulf.hansson@linaro.org>
Cc: "David S . Miller" <davem@davemloft.net>
Cc: Simon Horman <horms@verge.net.au>
Cc: Pravin B Shelar <pshelar@ovn.org>
Cc: Vlad Yasevich <vyasevich@gmail.com>
Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fq qdisc requires tstamp to be cleared in the forwarding path. Now ovs
doesn't clear skb->tstamp. We encountered a problem with linux
version 5.4.56 and ovs version 2.14.1, and packets failed to
dequeue from qdisc when fq qdisc was attached to ovs port.
Fixes: fb420d5d91 ("tcp/fq: move back to CLOCK_MONOTONIC")
Signed-off-by: kaixi.fan <fankaixi.li@bytedance.com>
Signed-off-by: xiexiaohui <xiexiaohui.xxh@bytedance.com>
Reviewed-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Repair kernel-doc notation in a few places to make it conform to
the expected format.
Fixes the following kernel-doc warnings:
flow.c:296: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
* Parse vlan tag from vlan header.
flow.c:296: warning: missing initial short description on line:
* Parse vlan tag from vlan header.
flow.c:537: warning: No description found for return value of 'key_extract_l3l4'
flow.c:769: warning: No description found for return value of 'key_extract'
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Pravin B Shelar <pshelar@ovn.org>
Cc: dev@openvswitch.org
Link: https://lore.kernel.org/r/20210808190834.23362-1-rdunlap@infradead.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
fix incorrect type in argument 1 (different address spaces)
../net/openvswitch/datapath.c:169:17: warning: incorrect type in argument 1 (different address spaces)
../net/openvswitch/datapath.c:169:17: expected void const *
../net/openvswitch/datapath.c:169:17: got struct dp_nlsk_pids [noderef] __rcu *upcall_portids
Found at: https://patchwork.kernel.org/project/netdevbpf/patch/20210630095350.817785-1-mark.d.gray@redhat.com/#24285159
Signed-off-by: Mark Gray <mark.d.gray@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The Open vSwitch kernel module uses the upcall mechanism to send
packets from kernel space to user space when it misses in the kernel
space flow table. The upcall sends packets via a Netlink socket.
Currently, a Netlink socket is created for every vport. In this way,
there is a 1:1 mapping between a vport and a Netlink socket.
When a packet is received by a vport, if it needs to be sent to
user space, it is sent via the corresponding Netlink socket.
This mechanism, with various iterations of the corresponding user
space code, has seen some limitations and issues:
* On systems with a large number of vports, there is a correspondingly
large number of Netlink sockets which can limit scaling.
(https://bugzilla.redhat.com/show_bug.cgi?id=1526306)
* Packet reordering on upcalls.
(https://bugzilla.redhat.com/show_bug.cgi?id=1844576)
* A thundering herd issue.
(https://bugzilla.redhat.com/show_bug.cgi?id=1834444)
This patch introduces an alternative, feature-negotiated, upcall
mode using a per-cpu dispatch rather than a per-vport dispatch.
In this mode, the Netlink socket to be used for the upcall is
selected based on the CPU of the thread that is executing the upcall.
In this way, it resolves the issues above as:
a) The number of Netlink sockets scales with the number of CPUs
rather than the number of vports.
b) Ordering per-flow is maintained as packets are distributed to
CPUs based on mechanisms such as RSS and flows are distributed
to a single user space thread.
c) Packets from a flow can only wake up one user space thread.
The corresponding user space code can be found at:
https://mail.openvswitch.org/pipermail/ovs-dev/2021-July/385139.html
Bugzilla: https://bugzilla.redhat.com/1844576
Signed-off-by: Mark Gray <mark.d.gray@redhat.com>
Acked-by: Flavio Leitner <fbl@sysclose.org>
Acked-by: Pravin B Shelar <pshelar@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
In the current implement when comparing two flow keys, we will return
result after comparing the whole key from start to end.
In our optimization, we will return result in the first none-zero
comparison, then we will improve the flow table looking up efficiency.
Signed-off-by: Baowen Zheng <baowen.zheng@corigine.com>
Signed-off-by: Louis Peens <louis.peens@corigine.com>
Signed-off-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This makes openvswitch module use the event tracing framework
to log the upcall interface and action execution pipeline. When
using openvswitch as the packet forwarding engine, some types of
debugging are made possible simply by using the ovs-vswitchd's
ofproto/trace command. However, such a command has some
limitations:
1. When trying to trace packets that go through the CT action,
the state of the packet can't be determined, and probably
would be potentially wrong.
2. Deducing problem packets can sometimes be difficult as well
even if many of the flows are known
3. It's possible to use the openvswitch module even without
the ovs-vswitchd (although, not common use).
Introduce the event tracing points here to make it possible for
working through these problems in kernel space. The style is
copied from the mac80211 driver-trace / trace code for
consistency - this creates some checkpatch splats, but the
official 'guide' for adding tracepoints, as well as the existing
examples all add the same splats so it seems acceptable.
Signed-off-by: Aaron Conole <aconole@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We have observed meters working unexpected if traffic is 3+Gbit/s
with multiple connections.
now_ms is not pretected by meter->lock, we may get a negative
long_delta_ms when another cpu updated meter->used, then:
delta_ms = (u32)long_delta_ms;
which will be a large value.
band->bucket += delta_ms * band->rate;
then we get a wrong band->bucket.
OpenVswitch userspace datapath has fixed the same issue[1] some
time ago, and we port the implementation to kernel datapath.
[1] https://patchwork.ozlabs.org/project/openvswitch/patch/20191025114436.9746-1-i.maximets@ovn.org/
Fixes: 96fbc13d7e ("openvswitch: Add meter infrastructure")
Signed-off-by: Tao Liu <thomas.liu@ucloud.cn>
Suggested-by: Ilya Maximets <i.maximets@ovn.org>
Reviewed-by: Ilya Maximets <i.maximets@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
There is no need add 'if (skb_nfct(skb))' assignment, the
nf_conntrack_put() would check it.
Signed-off-by: Yejune Deng <yejunedeng@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Implementation of meters supposed to be a classic token bucket with 2
typical parameters: rate and burst size.
Burst size in this schema is the maximum number of bytes/packets that
could pass without being rate limited.
Recent changes to userspace datapath made meter implementation to be
in line with the kernel one, and this uncovered several issues.
The main problem is that maximum bucket size for unknown reason
accounts not only burst size, but also the numerical value of rate.
This creates a lot of confusion around behavior of meters.
For example, if rate is configured as 1000 pps and burst size set to 1,
this should mean that meter will tolerate bursts of 1 packet at most,
i.e. not a single packet above the rate should pass the meter.
However, current implementation calculates maximum bucket size as
(rate + burst size), so the effective bucket size will be 1001. This
means that first 1000 packets will not be rate limited and average
rate might be twice as high as the configured rate. This also makes
it practically impossible to configure meter that will have burst size
lower than the rate, which might be a desirable configuration if the
rate is high.
Inability to configure low values of a burst size and overall inability
for a user to predict what will be a maximum and average rate from the
configured parameters of a meter without looking at the OVS and kernel
code might be also classified as a security issue, because drop meters
are frequently used as a way of protection from DoS attacks.
This change removes rate from the calculation of a bucket size, making
it in line with the classic token bucket algorithm and essentially
making the rate and burst tolerance being predictable from a users'
perspective.
Same change proposed for the userspace implementation.
Fixes: 96fbc13d7e ("openvswitch: Add meter infrastructure")
Signed-off-by: Ilya Maximets <i.maximets@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Conflicts:
MAINTAINERS
- keep Chandrasekar
drivers/net/ethernet/mellanox/mlx5/core/en_main.c
- simple fix + trust the code re-added to param.c in -next is fine
include/linux/bpf.h
- trivial
include/linux/ethtool.h
- trivial, fix kdoc while at it
include/linux/skmsg.h
- move to relevant place in tcp.c, comment re-wrapped
net/core/skmsg.c
- add the sk = sk // sk = NULL around calls
net/tipc/crypto.c
- trivial
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
'struct ovs_zone_limit' has more members than initialized in
ovs_ct_limit_get_default_limit(). The rest of the memory is a random
kernel stack content that ends up being sent to userspace.
Fix that by using designated initializer that will clear all
non-specified fields.
Fixes: 11efd5cb04 ("openvswitch: Support conntrack zone limit")
Signed-off-by: Ilya Maximets <i.maximets@ovn.org>
Acked-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
'skb_push()'/'skb_postpush_rcsum()' can be replaced by an equivalent
'skb_push_rcsum()' which is less verbose.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
s/subsytem/subsystem/
Signed-off-by: Bhaskar Chowdhury <unixbhaskar@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
It is not unusual to have the bridge port down. Sometimes
it has the old MTU, which is fine since it's not being used.
However, the kernel spams the log with a warning message
when a packet is going to be sent over such port. Fix that
by warning only if the interface is UP.
Signed-off-by: Flavio Leitner <fbl@sysclose.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
When openvswitch conntrack offload with act_ct action. The first rule
do conntrack in the act_ct in tc subsystem. And miss the next rule in
the tc and fallback to the ovs datapath but miss set post_ct flag
which will lead the ct_state_key with -trk flag.
Fixes: 7baf2429a1 ("net/sched: cls_flower add CT_FLAGS_INVALID flag support")
Signed-off-by: wenxu <wenxu@ucloud.cn>
Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
As requested by upstream OVS, added some error messages in the
validate_and_copy_dec_ttl function.
Includes a small cleanup, which removes an unnecessary parameter
from the dec_ttl_exception_handler() function.
Reported-by: Flavio Leitner <fbl@sysclose.org>
Signed-off-by: Eelco Chaudron <echaudro@redhat.com>
Acked-by: Flavio Leitner <fbl@sysclose.org>
Link: https://lore.kernel.org/r/161054576573.26637.18396634650212670580.stgit@ebuild
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Currently, the exception actions are not processed correctly as the wrong
dataset is passed. This change fixes this, including the misleading
comment.
In addition, a check was added to make sure we work on an IPv4 packet,
and not just assume if it's not IPv6 it's IPv4.
This was all tested using OVS with patch,
https://patchwork.ozlabs.org/project/openvswitch/list/?series=21639,
applied and sending packets with a TTL of 1 (and 0), both with IPv4
and IPv6.
Fixes: 69929d4c49 ("net: openvswitch: fix TTL decrement action netlink message format")
Signed-off-by: Eelco Chaudron <echaudro@redhat.com>
Link: https://lore.kernel.org/r/160733569860.3007.12938188180387116741.stgit@wsfd-netdev64.ntdv.lab.eng.bos.redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
xdp_return_frame_bulk() needs to pass a xdp_buff
to __xdp_return().
strlcpy got converted to strscpy but here it makes no
functional difference, so just keep the right code.
Conflicts:
net/netfilter/nf_tables_api.c
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Simplify the return expression.
Signed-off-by: Zheng Yongjun <zhengyongjun3@huawei.com>
Reviewed-by: Eelco Chaudron <echaudro@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix to return a negative error code from the error handling
case instead of 0, as done elsewhere in this function.
Changing 'return start' to 'return action_start' can fix this bug.
Fixes: 69929d4c49 ("net: openvswitch: fix TTL decrement action netlink message format")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wang Hai <wanghai38@huawei.com>
Reviewed-by: Eelco Chaudron <echaudro@redhat.com>
Link: https://lore.kernel.org/r/20201204114314.1596-1-wanghai38@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
when openvswitch is configured to mangle the LSE, the current value is
read from the packet dereferencing 4 bytes at mpls_hdr(): ensure that
the label is contained in the skb "linear" area.
Found by code inspection.
Fixes: d27cf5c59a ("net: core: add MPLS update core helper and use in OvS")
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Link: https://lore.kernel.org/r/aa099f245d93218b84b5c056b67b6058ccf81a66.1606987185.git.dcaratti@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Trivial conflict in CAN, keep the net-next + the byteswap wrapper.
Conflicts:
drivers/net/can/usb/gs_usb.c
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Currently, the openvswitch module is not accepting the correctly formated
netlink message for the TTL decrement action. For both setting and getting
the dec_ttl action, the actions should be nested in the
OVS_DEC_TTL_ATTR_ACTION attribute as mentioned in the openvswitch.h uapi.
When the original patch was sent, it was tested with a private OVS userspace
implementation. This implementation was unfortunately not upstreamed and
reviewed, hence an erroneous version of this patch was sent out.
Leaving the patch as-is would cause problems as the kernel module could
interpret additional attributes as actions and vice-versa, due to the
actions not being encapsulated/nested within the actual attribute, but
being concatinated after it.
Fixes: 744676e777 ("openvswitch: add TTL decrement action")
Signed-off-by: Eelco Chaudron <echaudro@redhat.com>
Link: https://lore.kernel.org/r/160622121495.27296.888010441924340582.stgit@wsfd-netdev64.ntdv.lab.eng.bos.redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
There is no easy way to distinguish if a conntracked tcp packet is
marked invalid because of tcp_in_window() check error or because
it doesn't belong to an existing connection. With this patch,
openvswitch sets liberal tcp flag for the established sessions so
that out of window packets are not marked invalid.
A helper function - nf_ct_set_tcp_be_liberal(nf_conn) is added which
sets this flag for both the directions of the nf_conn.
Suggested-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Numan Siddique <nusiddiq@redhat.com>
Acked-by: Florian Westphal <fw@strlen.de>
Link: https://lore.kernel.org/r/20201116130126.3065077-1-nusiddiq@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Commit d3fd65484c ("net: core: add dev_sw_netstats_tx_add") has added
function "dev_sw_netstats_tx_add()" to update net device per-cpu TX
stats.
Use this function instead of own code.
While on it, remove internal_get_stats() and replace it
with dev_get_tstats64().
Signed-off-by: Lev Stipakov <lev@openvpn.net>
Reviewed-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/20201113215336.145998-1-lev@openvpn.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Fix smatch warning:
net/openvswitch/meter.c:427 ovs_meter_cmd_set() warn: passing zero to 'PTR_ERR'
dp_meter_create() never returns NULL, use IS_ERR
instead of IS_ERR_OR_NULL to fix this.
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
Link: https://lore.kernel.org/r/20201031060153.39912-1-yuehaibing@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net/openvswitch/flow.c:303: warning: Function parameter or member 'key_vh' not described in 'parse_vlan_tag'
net/openvswitch/flow.c:303: warning: Function parameter or member 'skb' not described in 'parse_vlan_tag'
net/openvswitch/flow.c:303: warning: Function parameter or member 'untag_vlan' not described in 'parse_vlan_tag'
net/openvswitch/vport.c:122: warning: Function parameter or member 'parms' not described in 'ovs_vport_alloc'
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20201028004849.930094-1-andrew@lunn.ch
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The flow_lookup() function uses per CPU variables, which must be called
with BH disabled. However, this is fine in the general NAPI use case
where the local BH is disabled. But, it's also called from the netlink
context. The below patch makes sure that even in the netlink path, the
BH is disabled.
In addition, u64_stats_update_begin() requires a lock to ensure one writer
which is not ensured here. Making it per-CPU and disabling NAPI (softirq)
ensures that there is always only one writer.
Fixes: eac87c413b ("net: openvswitch: reorder masks array based on usage")
Reported-by: Juri Lelli <jlelli@redhat.com>
Signed-off-by: Eelco Chaudron <echaudro@redhat.com>
Link: https://lore.kernel.org/r/160295903253.7789.826736662555102345.stgit@ebuild
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Small conflict around locking in rxrpc_process_event() -
channel_lock moved to bundle in next, while state lock
needs _bh() from net.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
With multiple DNAT rules it's possible that after destination
translation the resulting tuples collide.
For example, two openvswitch flows:
nw_dst=10.0.0.10,tp_dst=10, actions=ct(commit,table=2,nat(dst=20.0.0.1:20))
nw_dst=10.0.0.20,tp_dst=10, actions=ct(commit,table=2,nat(dst=20.0.0.1:20))
Assuming two TCP clients initiating the following connections:
10.0.0.10:5000->10.0.0.10:10
10.0.0.10:5000->10.0.0.20:10
Both tuples would translate to 10.0.0.10:5000->20.0.0.1:20 causing
nf_conntrack_confirm() to fail because of tuple collision.
Netfilter handles this case by allocating a null binding for SNAT at
egress by default. Perform the same operation in openvswitch for DNAT
if no explicit SNAT is requested by the user and allocate a null binding
for SNAT for packets in the "original" direction.
Reported-at: https://bugzilla.redhat.com/1877128
Suggested-by: Florian Westphal <fw@strlen.de>
Fixes: 05752523e5 ("openvswitch: Interface with NAT.")
Signed-off-by: Dumitru Ceara <dceara@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
