inet: introduce dst_rtable() helper

I added dst_rt6_info() in commit
e8dfd42c17fa ("ipv6: introduce dst_rt6_info() helper")

This patch does a similar change for IPv4.

Instead of (struct rtable *)d

inet: introduce dst_rtable() helper

I added dst_rt6_info() in commit
e8dfd42c17fa ("ipv6: introduce dst_rt6_info() helper")

This patch does a similar change for IPv4.

Instead of (struct rtable *)dst casts, we can use :

#define dst_rtable(_ptr) \
container_of_const(_ptr, struct rtable, dst)

Patch is smaller than IPv6 one, because IPv4 has skb_rtable() helper.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Link: https://lore.kernel.org/r/20240429133009.1227754-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

show more ...

ipv6: introduce dst_rt6_info() helper

Instead of (struct rt6_info *)dst casts, we can use :

#define dst_rt6_info(_ptr) \
container_of_const(_ptr, struct rt6_info, dst)

Some places needed

ipv6: introduce dst_rt6_info() helper

Instead of (struct rt6_info *)dst casts, we can use :

#define dst_rt6_info(_ptr) \
container_of_const(_ptr, struct rt6_info, dst)

Some places needed missing const qualifiers :

ip6_confirm_neigh(), ipv6_anycast_destination(),
ipv6_unicast_destination(), has_gateway()

v2: added missing parts (David Ahern)

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

sysctl: treewide: constify ctl_table_header::ctl_table_arg

To be able to constify instances of struct ctl_tables it is necessary to
remove ways through which non-const versions are exposed from the

sysctl: treewide: constify ctl_table_header::ctl_table_arg

To be able to constify instances of struct ctl_tables it is necessary to
remove ways through which non-const versions are exposed from the
sysctl core.
One of these is the ctl_table_arg member of struct ctl_table_header.

Constify this reference as a prerequisite for the full constification of
struct ctl_table instances.
No functional change.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

net: Move {l,t,d}stats allocation to core and convert veth & vrf

Move {l,t,d}stats allocation to the core and let netdevs pick the stats
type they need. That way the driver doesn't have to bother wi

net: Move {l,t,d}stats allocation to core and convert veth & vrf

Move {l,t,d}stats allocation to the core and let netdevs pick the stats
type they need. That way the driver doesn't have to bother with error
handling (allocation failure checking, making sure free happens in the
right spot, etc) - all happening in the core.

Co-developed-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Cc: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20231114004220.6495-3-daniel@iogearbox.net
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>

show more ...

net, vrf: Move dstats structure to core

Just move struct pcpu_dstats out of the vrf into the core, and streamline
the field names slightly, so they better align with the {t,l}stats ones.

No functio

net, vrf: Move dstats structure to core

Just move struct pcpu_dstats out of the vrf into the core, and streamline
the field names slightly, so they better align with the {t,l}stats ones.

No functional change otherwise. A conversion of the u64s to u64_stats_t
could be done at a separate point in future. This move is needed as we are
moving the {t,l,d}stats allocation/freeing to the core.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20231114004220.6495-2-daniel@iogearbox.net
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>

show more ...

vrf: Remove the now superfluous sentinel element from ctl_table array

This commit comes at the tail end of a greater effort to remove the
empty elements at the end of the ctl_table arrays (sentinels

vrf: Remove the now superfluous sentinel element from ctl_table array

This commit comes at the tail end of a greater effort to remove the
empty elements at the end of the ctl_table arrays (sentinels) which
will reduce the overall build time size of the kernel and run time
memory bloat by ~64 bytes per sentinel (further information Link :
https://lore.kernel.org/all/ZO5Yx5JFogGi%2FcBo@bombadil.infradead.org/)

Remove sentinel from vrf_table

Signed-off-by: Joel Granados <j.granados@samsung.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>

show more ...

vrf: Remove unnecessary RCU-bh critical section

dev_queue_xmit_nit() already uses rcu_read_lock() / rcu_read_unlock()
and nothing suggests that softIRQs should be disabled around it.
Therefore, remo

vrf: Remove unnecessary RCU-bh critical section

dev_queue_xmit_nit() already uses rcu_read_lock() / rcu_read_unlock()
and nothing suggests that softIRQs should be disabled around it.
Therefore, remove the rcu_read_lock_bh() / rcu_read_unlock_bh()
surrounding it.

Tested using [1] with lockdep enabled.

[1]
#!/bin/bash

ip link add name vrf1 up type vrf table 100
ip link add name veth0 type veth peer name veth1
ip link set dev veth1 master vrf1
ip link set dev veth0 up
ip link set dev veth1 up
ip address add 192.0.2.1/24 dev veth0
ip address add 192.0.2.2/24 dev veth1
ip rule add pref 32765 table local
ip rule del pref 0
tcpdump -i vrf1 -c 20 -w /dev/null &
sleep 10
ping -i 0.1 -c 10 -q 192.0.2.2

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20230821142339.1889961-1-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

show more ...

vrf: Update to register_net_sysctl_sz

Move from register_net_sysctl to register_net_sysctl_sz and pass the
ARRAY_SIZE of the ctl_table array that was used to create the table
variable. We need to mo

vrf: Update to register_net_sysctl_sz

Move from register_net_sysctl to register_net_sysctl_sz and pass the
ARRAY_SIZE of the ctl_table array that was used to create the table
variable. We need to move to the new function in preparation for when we
change SIZE_MAX to ARRAY_SIZE() in the register_net_sysctl macro.
Failing to do so would erroneously allow ARRAY_SIZE() to be called on a
pointer. The actual change from SIZE_MAX to ARRAY_SIZE will take place
in subsequent commits.

Signed-off-by: Joel Granados <j.granados@samsung.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>

show more ...

vrf: Fix lockdep splat in output path

Cited commit converted the neighbour code to use the standard RCU
variant instead of the RCU-bh variant, but the VRF code still uses
rcu_read_lock_bh() / rcu_re

vrf: Fix lockdep splat in output path

Cited commit converted the neighbour code to use the standard RCU
variant instead of the RCU-bh variant, but the VRF code still uses
rcu_read_lock_bh() / rcu_read_unlock_bh() around the neighbour lookup
code in its IPv4 and IPv6 output paths, resulting in lockdep splats
[1][2]. Can be reproduced using [3].

Fix by switching to rcu_read_lock() / rcu_read_unlock().

[1]
=============================
WARNING: suspicious RCU usage
6.5.0-rc1-custom-g9c099e6dbf98 #403 Not tainted
-----------------------------
include/net/neighbour.h:302 suspicious rcu_dereference_check() usage!

other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1
2 locks held by ping/183:
#0: ffff888105ea1d80 (sk_lock-AF_INET){+.+.}-{0:0}, at: raw_sendmsg+0xc6c/0x33c0
#1: ffffffff85b46820 (rcu_read_lock_bh){....}-{1:2}, at: vrf_output+0x2e3/0x2030

stack backtrace:
CPU: 0 PID: 183 Comm: ping Not tainted 6.5.0-rc1-custom-g9c099e6dbf98 #403
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-1.fc37 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0xc1/0xf0
lockdep_rcu_suspicious+0x211/0x3b0
vrf_output+0x1380/0x2030
ip_push_pending_frames+0x125/0x2a0
raw_sendmsg+0x200d/0x33c0
inet_sendmsg+0xa2/0xe0
__sys_sendto+0x2aa/0x420
__x64_sys_sendto+0xe5/0x1c0
do_syscall_64+0x38/0x80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

[2]
=============================
WARNING: suspicious RCU usage
6.5.0-rc1-custom-g9c099e6dbf98 #403 Not tainted
-----------------------------
include/net/neighbour.h:302 suspicious rcu_dereference_check() usage!

other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1
2 locks held by ping6/182:
#0: ffff888114b63000 (sk_lock-AF_INET6){+.+.}-{0:0}, at: rawv6_sendmsg+0x1602/0x3e50
#1: ffffffff85b46820 (rcu_read_lock_bh){....}-{1:2}, at: vrf_output6+0xe9/0x1310

stack backtrace:
CPU: 0 PID: 182 Comm: ping6 Not tainted 6.5.0-rc1-custom-g9c099e6dbf98 #403
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-1.fc37 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0xc1/0xf0
lockdep_rcu_suspicious+0x211/0x3b0
vrf_output6+0xd32/0x1310
ip6_local_out+0xb4/0x1a0
ip6_send_skb+0xbc/0x340
ip6_push_pending_frames+0xe5/0x110
rawv6_sendmsg+0x2e6e/0x3e50
inet_sendmsg+0xa2/0xe0
__sys_sendto+0x2aa/0x420
__x64_sys_sendto+0xe5/0x1c0
do_syscall_64+0x38/0x80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

[3]
#!/bin/bash

ip link add name vrf-red up numtxqueues 2 type vrf table 10
ip link add name swp1 up master vrf-red type dummy
ip address add 192.0.2.1/24 dev swp1
ip address add 2001:db8:1::1/64 dev swp1
ip neigh add 192.0.2.2 lladdr 00:11:22:33:44:55 nud perm dev swp1
ip neigh add 2001:db8:1::2 lladdr 00:11:22:33:44:55 nud perm dev swp1
ip vrf exec vrf-red ping 192.0.2.2 -c 1 &> /dev/null
ip vrf exec vrf-red ping6 2001:db8:1::2 -c 1 &> /dev/null

Fixes: 09eed1192cec ("neighbour: switch to standard rcu, instead of rcu_bh")
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Link: https://lore.kernel.org/netdev/CA+G9fYtEr-=GbcXNDYo3XOkwR+uYgehVoDjsP0pFLUpZ_AZcyg@mail.gmail.com/
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20230715153605.4068066-1-idosch@nvidia.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

show more ...

net: vrf: determine the dst using the original ifindex for multicast

Multicast packets received on an interface bound to a VRF are marked as
belonging to the VRF and the skb device is updated to poi

net: vrf: determine the dst using the original ifindex for multicast

Multicast packets received on an interface bound to a VRF are marked as
belonging to the VRF and the skb device is updated to point to the VRF
device itself. This was fine even when a route was associated to a
device as when performing a fib table lookup 'oif' in fib6_table_lookup
(coming from 'skb->dev->ifindex' in ip6_route_input) was set to 0 when
FLOWI_FLAG_SKIP_NH_OIF was set.

With commit 40867d74c374 ("net: Add l3mdev index to flow struct and
avoid oif reset for port devices") this is not longer true and multicast
traffic is not received on the original interface.

Instead of adding back a similar check in fib6_table_lookup determine
the dst using the original ifindex for multicast VRF traffic. To make
things consistent across the function do the above for all strict
packets, which was the logic before commit 6f12fa775530 ("vrf: mark skb
for multicast or link-local as enslaved to VRF"). Note that reverting to
this behavior should be fine as the change was about marking packets
belonging to the VRF, not about their dst.

Fixes: 40867d74c374 ("net: Add l3mdev index to flow struct and avoid oif reset for port devices")
Reported-by: Jianlin Shi <jishi@redhat.com>
Signed-off-by: Antoine Tenart <atenart@kernel.org>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20221220171825.1172237-1-atenart@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

show more ...

net: Remove the obsolte u64_stats_fetch_*_irq() users (drivers).

Now that the 32bit UP oddity is gone and 32bit uses always a sequence
count, there is no need for the fetch_irq() variants anymore.

net: Remove the obsolte u64_stats_fetch_*_irq() users (drivers).

Now that the 32bit UP oddity is gone and 32bit uses always a sequence
count, there is no need for the fetch_irq() variants anymore.

Convert to the regular interface.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

show more ...

net: move from strlcpy with unused retval to strscpy

Follow the advice of the below link and prefer 'strscpy' in this
subsystem. Conversion is 1:1 because the return value is not used.
Generated by

net: move from strlcpy with unused retval to strscpy

Follow the advice of the below link and prefer 'strscpy' in this
subsystem. Conversion is 1:1 because the return value is not used.
Generated by a coccinelle script.

Link: https://lore.kernel.org/r/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw@mail.gmail.com/
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de> # for CAN
Link: https://lore.kernel.org/r/20220830201457.7984-1-wsa+renesas@sang-engineering.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

show more ...

xfrm: no need to set DST_NOPOLICY in IPv4

This is a cleanup patch following commit e6175a2ed1f1
("xfrm: fix "disable_policy" flag use when arriving from different devices")
which made DST_NOPOLICY n

xfrm: no need to set DST_NOPOLICY in IPv4

This is a cleanup patch following commit e6175a2ed1f1
("xfrm: fix "disable_policy" flag use when arriving from different devices")
which made DST_NOPOLICY no longer be used for inbound policy checks.

On outbound the flag was set, but never used.

As such, avoid setting it altogether and remove the nopolicy argument
from rt_dst_alloc().

Signed-off-by: Eyal Birger <eyal.birger@gmail.com>
Reviewed-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

show more ...

net: rename reference+tracking helpers

Netdev reference helpers have a dev_ prefix for historic
reasons. Renaming the old helpers would be too much churn
but we can rename the tracking ones which ar

net: rename reference+tracking helpers

Netdev reference helpers have a dev_ prefix for historic
reasons. Renaming the old helpers would be too much churn
but we can rename the tracking ones which are relatively
recent and should be the default for new code.

Rename:
dev_hold_track() -> netdev_hold()
dev_put_track() -> netdev_put()
dev_replace_track() -> netdev_ref_replace()

Link: https://lore.kernel.org/r/20220608043955.919359-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

show more ...

vrf: fix packet sniffing for traffic originating from ip tunnels

in commit 048939088220
("vrf: add mac header for tunneled packets when sniffer is attached")
an Ethernet header was cooked for traffi

vrf: fix packet sniffing for traffic originating from ip tunnels

in commit 048939088220
("vrf: add mac header for tunneled packets when sniffer is attached")
an Ethernet header was cooked for traffic originating from tunnel devices.

However, the header is added based on whether the mac_header is unset
and ignores cases where the device doesn't expose a mac header to upper
layers, such as in ip tunnels like ipip and gre.

Traffic originating from such devices still appears garbled when capturing
on the vrf device.

Fix by observing whether the original device exposes a header to upper
layers, similar to the logic done in af_packet.

In addition, skb->mac_len needs to be adjusted after adding the Ethernet
header for the skb_push/pull() surrounding dev_queue_xmit_nit() to work
on these packets.

Fixes: 048939088220 ("vrf: add mac header for tunneled packets when sniffer is attached")
Signed-off-by: Eyal Birger <eyal.birger@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

net: Add l3mdev index to flow struct and avoid oif reset for port devices

The fundamental premise of VRF and l3mdev core code is binding a socket
to a device (l3mdev or netdev with an L3 domain) to

net: Add l3mdev index to flow struct and avoid oif reset for port devices

The fundamental premise of VRF and l3mdev core code is binding a socket
to a device (l3mdev or netdev with an L3 domain) to indicate L3 scope.
Legacy code resets flowi_oif to the l3mdev losing any original port
device binding. Ben (among others) has demonstrated use cases where the
original port device binding is important and needs to be retained.
This patch handles that by adding a new entry to the common flow struct
that can indicate the l3mdev index for later rule and table matching
avoiding the need to reset flowi_oif.

In addition to allowing more use cases that require port device binds,
this patch brings a few datapath simplications:

1. l3mdev_fib_rule_match is only called when walking fib rules and
always after l3mdev_update_flow. That allows an optimization to bail
early for non-VRF type uses cases when flowi_l3mdev is not set. Also,
only that index needs to be checked for the FIB table id.

2. l3mdev_update_flow can be called with flowi_oif set to a l3mdev
(e.g., VRF) device. By resetting flowi_oif only for this case the
FLOWI_FLAG_SKIP_NH_OIF flag is not longer needed and can be removed,
removing several checks in the datapath. The flowi_iif path can be
simplified to only be called if the it is not loopback (loopback can
not be assigned to an L3 domain) and the l3mdev index is not already
set.

3. Avoid another device lookup in the output path when the fib lookup
returns a reject failure.

Note: 2 functional tests for local traffic with reject fib rules are
updated to reflect the new direct failure at FIB lookup time for ping
rather than the failure on packet path. The current code fails like this:

HINT: Fails since address on vrf device is out of device scope
COMMAND: ip netns exec ns-A ping -c1 -w1 -I eth1 172.16.3.1
ping: Warning: source address might be selected on device other than: eth1
PING 172.16.3.1 (172.16.3.1) from 172.16.3.1 eth1: 56(84) bytes of data.

--- 172.16.3.1 ping statistics ---
1 packets transmitted, 0 received, 100% packet loss, time 0ms

where the test now directly fails:

HINT: Fails since address on vrf device is out of device scope
COMMAND: ip netns exec ns-A ping -c1 -w1 -I eth1 172.16.3.1
ping: connect: No route to host

Signed-off-by: David Ahern <dsahern@kernel.org>
Tested-by: Ben Greear <greearb@candelatech.com>
Link: https://lore.kernel.org/r/20220314204551.16369-1-dsahern@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

show more ...

net: dev: Makes sure netif_rx() can be invoked in any context.

Dave suggested a while ago (eleven years by now) "Let's make netif_rx()
work in all contexts and get rid of netif_rx_ni()". Eric agreed

net: dev: Makes sure netif_rx() can be invoked in any context.

Dave suggested a while ago (eleven years by now) "Let's make netif_rx()
work in all contexts and get rid of netif_rx_ni()". Eric agreed and
pointed out that modern devices should use netif_receive_skb() to avoid
the overhead.
In the meantime someone added another variant, netif_rx_any_context(),
which behaves as suggested.

netif_rx() must be invoked with disabled bottom halves to ensure that
pending softirqs, which were raised within the function, are handled.
netif_rx_ni() can be invoked only from process context (bottom halves
must be enabled) because the function handles pending softirqs without
checking if bottom halves were disabled or not.
netif_rx_any_context() invokes on the former functions by checking
in_interrupts().

netif_rx() could be taught to handle both cases (disabled and enabled
bottom halves) by simply disabling bottom halves while invoking
netif_rx_internal(). The local_bh_enable() invocation will then invoke
pending softirqs only if the BH-disable counter drops to zero.

Eric is concerned about the overhead of BH-disable+enable especially in
regard to the loopback driver. As critical as this driver is, it will
receive a shortcut to avoid the additional overhead which is not needed.

Add a local_bh_disable() section in netif_rx() to ensure softirqs are
handled if needed.
Provide __netif_rx() which does not disable BH and has a lockdep assert
to ensure that interrupts are disabled. Use this shortcut in the
loopback driver and in drivers/net/*.c.
Make netif_rx_ni() and netif_rx_any_context() invoke netif_rx() so they
can be removed once they are no more users left.

Link: https://lkml.kernel.org/r/20100415.020246.218622820.davem@davemloft.net
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

net: Don't include filter.h from net/sock.h

sock.h is pretty heavily used (5k objects rebuilt on x86 after
it's touched). We can drop the include of filter.h from it and
add a forward declaration of

net: Don't include filter.h from net/sock.h

sock.h is pretty heavily used (5k objects rebuilt on x86 after
it's touched). We can drop the include of filter.h from it and
add a forward declaration of struct sk_filter instead.
This decreases the number of rebuilt objects when bpf.h
is touched from ~5k to ~1k.

There's a lot of missing includes this was masking. Primarily
in networking tho, this time.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Acked-by: Stefano Garzarella <sgarzare@redhat.com>
Link: https://lore.kernel.org/bpf/20211229004913.513372-1-kuba@kernel.org

show more ...

vrf: don't run conntrack on vrf with !dflt qdisc

After the below patch, the conntrack attached to skb is set to "notrack" in
the context of vrf device, for locally generated packets.
But this is tru

vrf: don't run conntrack on vrf with !dflt qdisc

After the below patch, the conntrack attached to skb is set to "notrack" in
the context of vrf device, for locally generated packets.
But this is true only when the default qdisc is set to the vrf device. When
changing the qdisc, notrack is not set anymore.
In fact, there is a shortcut in the vrf driver, when the default qdisc is
set, see commit dcdd43c41e60 ("net: vrf: performance improvements for
IPv4") for more details.

This patch ensures that the behavior is always the same, whatever the qdisc
is.

To demonstrate the difference, a new test is added in conntrack_vrf.sh.

Fixes: 8c9c296adfae ("vrf: run conntrack only in context of lower/physdev for locally generated packets")
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Florian Westphal <fw@strlen.de>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

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vrf: use dev_replace_track() for better tracking

vrf_rt6_release() and vrf_rtable_release() changes dst->dev

Instead of

dev_hold(ndev);
dev_put(odev);

We should use

dev_replace_track(odev, ndev,

vrf: use dev_replace_track() for better tracking

vrf_rt6_release() and vrf_rtable_release() changes dst->dev

Instead of

dev_hold(ndev);
dev_put(odev);

We should use

dev_replace_track(odev, ndev, &dst->dev_tracker, GFP_KERNEL);

If we do not transfer dst->dev_tracker to the new device,
we will get warnings from ref_tracker_dir_exit() when odev
is finally dismantled.

Fixes: 9038c320001d ("net: dst: add net device refcount tracking to dst_entry")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20211207055603.1926372-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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vrf: Reset IPCB/IP6CB when processing outbound pkts in vrf dev xmit

IPCB/IP6CB need to be initialized when processing outbound v4 or v6 pkts
in the codepath of vrf device xmit function so that lefto

vrf: Reset IPCB/IP6CB when processing outbound pkts in vrf dev xmit

IPCB/IP6CB need to be initialized when processing outbound v4 or v6 pkts
in the codepath of vrf device xmit function so that leftover garbage
doesn't cause futher code that uses the CB to incorrectly process the
pkt.

One occasion of the issue might occur when MPLS route uses the vrf
device as the outgoing device such as when the route is added using "ip
-f mpls route add <label> dev <vrf>" command.

The problems seems to exist since day one. Hence I put the day one
commits on the Fixes tags.

Fixes: 193125dbd8eb ("net: Introduce VRF device driver")
Fixes: 35402e313663 ("net: Add IPv6 support to VRF device")
Cc: stable@vger.kernel.org
Signed-off-by: Stephen Suryaputra <ssuryaextr@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20211130162637.3249-1-ssuryaextr@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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vrf: run conntrack only in context of lower/physdev for locally generated packets

The VRF driver invokes netfilter for output+postrouting hooks so that users
can create rules that check for 'oif $vr

vrf: run conntrack only in context of lower/physdev for locally generated packets

The VRF driver invokes netfilter for output+postrouting hooks so that users
can create rules that check for 'oif $vrf' rather than lower device name.

This is a problem when NAT rules are configured.

To avoid any conntrack involvement in round 1, tag skbs as 'untracked'
to prevent conntrack from picking them up.

This gets cleared before the packet gets handed to the ip stack so
conntrack will be active on the second iteration.

One remaining issue is that a rule like

output ... oif $vrfname notrack

won't propagate to the second round because we can't tell
'notrack set via ruleset' and 'notrack set by vrf driver' apart.
However, this isn't a regression: the 'notrack' removal happens
instead of unconditional nf_reset_ct().
I'd also like to avoid leaking more vrf specific conditionals into the
netfilter infra.

For ingress, conntrack has already been done before the packet makes it
to the vrf driver, with this patch egress does connection tracking with
lower/physical device as well.

Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

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vrf: Revert "Reset skb conntrack connection..."

This reverts commit 09e856d54bda5f288ef8437a90ab2b9b3eab83d1.

When an interface is enslaved in a VRF, prerouting conntrack hook is
called twice: once

vrf: Revert "Reset skb conntrack connection..."

This reverts commit 09e856d54bda5f288ef8437a90ab2b9b3eab83d1.

When an interface is enslaved in a VRF, prerouting conntrack hook is
called twice: once in the context of the original input interface, and
once in the context of the VRF interface. If no special precausions are
taken, this leads to creation of two conntrack entries instead of one,
and breaks SNAT.

Commit above was intended to avoid creation of extra conntrack entries
when input interface is enslaved in a VRF. It did so by resetting
conntrack related data associated with the skb when it enters VRF context.

However it breaks netfilter operation. Imagine a use case when conntrack
zone must be assigned based on the original input interface, rather than
VRF interface (that would make original interfaces indistinguishable). One
could create netfilter rules similar to these:

chain rawprerouting {
type filter hook prerouting priority raw;
iif realiface1 ct zone set 1 return
iif realiface2 ct zone set 2 return
}

This works before the mentioned commit, but not after: zone assignment
is "forgotten", and any subsequent NAT or filtering that is dependent
on the conntrack zone does not work.

Here is a reproducer script that demonstrates the difference in behaviour.

==========
#!/bin/sh

# This script demonstrates unexpected change of nftables behaviour
# caused by commit 09e856d54bda5f28 ""vrf: Reset skb conntrack
# connection on VRF rcv"
# https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=09e856d54bda5f288ef8437a90ab2b9b3eab83d1
#
# Before the commit, it was possible to assign conntrack zone to a
# packet (or mark it for `notracking`) in the prerouting chanin, raw
# priority, based on the `iif` (interface from which the packet
# arrived).
# After the change, # if the interface is enslaved in a VRF, such
# assignment is lost. Instead, assignment based on the `iif` matching
# the VRF master interface is honored. Thus it is impossible to
# distinguish packets based on the original interface.
#
# This script demonstrates this change of behaviour: conntrack zone 1
# or 2 is assigned depending on the match with the original interface
# or the vrf master interface. It can be observed that conntrack entry
# appears in different zone in the kernel versions before and after
# the commit.

IPIN=172.30.30.1
IPOUT=172.30.30.2
PFXL=30

ip li sh vein >/dev/null 2>&1 && ip li del vein
ip li sh tvrf >/dev/null 2>&1 && ip li del tvrf
nft list table testct >/dev/null 2>&1 && nft delete table testct

ip li add vein type veth peer veout
ip li add tvrf type vrf table 9876
ip li set veout master tvrf
ip li set vein up
ip li set veout up
ip li set tvrf up
/sbin/sysctl -w net.ipv4.conf.veout.accept_local=1
/sbin/sysctl -w net.ipv4.conf.veout.rp_filter=0
ip addr add $IPIN/$PFXL dev vein
ip addr add $IPOUT/$PFXL dev veout

nft -f - <<__END__
table testct {
chain rawpre {
type filter hook prerouting priority raw;
iif { veout, tvrf } meta nftrace set 1
iif veout ct zone set 1 return
iif tvrf ct zone set 2 return
notrack
}
chain rawout {
type filter hook output priority raw;
notrack
}
}
__END__

uname -rv
conntrack -F
ping -W 1 -c 1 -I vein $IPOUT
conntrack -L

Signed-off-by: Eugene Crosser <crosser@average.org>
Acked-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

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vrf: Reset skb conntrack connection on VRF rcv

To fix the "reverse-NAT" for replies.

When a packet is sent over a VRF, the POST_ROUTING hooks are called
twice: Once from the VRF interface, and once

vrf: Reset skb conntrack connection on VRF rcv

To fix the "reverse-NAT" for replies.

When a packet is sent over a VRF, the POST_ROUTING hooks are called
twice: Once from the VRF interface, and once from the "actual"
interface the packet will be sent from:
1) First SNAT: l3mdev_l3_out() -> vrf_l3_out() -> .. -> vrf_output_direct()
This causes the POST_ROUTING hooks to run.
2) Second SNAT: 'ip_output()' calls POST_ROUTING hooks again.

Similarly for replies, first ip_rcv() calls PRE_ROUTING hooks, and
second vrf_l3_rcv() calls them again.

As an example, consider the following SNAT rule:
> iptables -t nat -A POSTROUTING -p udp -m udp --dport 53 -j SNAT --to-source 2.2.2.2 -o vrf_1

In this case sending over a VRF will create 2 conntrack entries.
The first is from the VRF interface, which performs the IP SNAT.
The second will run the SNAT, but since the "expected reply" will remain
the same, conntrack randomizes the source port of the packet:
e..g With a socket bound to 1.1.1.1:10000, sending to 3.3.3.3:53, the conntrack
rules are:
udp 17 29 src=2.2.2.2 dst=3.3.3.3 sport=10000 dport=53 packets=1 bytes=68 [UNREPLIED] src=3.3.3.3 dst=2.2.2.2 sport=53 dport=61033 packets=0 bytes=0 mark=0 use=1
udp 17 29 src=1.1.1.1 dst=3.3.3.3 sport=10000 dport=53 packets=1 bytes=68 [UNREPLIED] src=3.3.3.3 dst=2.2.2.2 sport=53 dport=10000 packets=0 bytes=0 mark=0 use=1

i.e. First SNAT IP from 1.1.1.1 --> 2.2.2.2, and second the src port is
SNAT-ed from 10000 --> 61033.

But when a reply is sent (3.3.3.3:53 -> 2.2.2.2:61033) only the later
conntrack entry is matched:
udp 17 29 src=2.2.2.2 dst=3.3.3.3 sport=10000 dport=53 packets=1 bytes=68 src=3.3.3.3 dst=2.2.2.2 sport=53 dport=61033 packets=1 bytes=49 mark=0 use=1
udp 17 28 src=1.1.1.1 dst=3.3.3.3 sport=10000 dport=53 packets=1 bytes=68 [UNREPLIED] src=3.3.3.3 dst=2.2.2.2 sport=53 dport=10000 packets=0 bytes=0 mark=0 use=1

And a "port 61033 unreachable" ICMP packet is sent back.

The issue is that when PRE_ROUTING hooks are called from vrf_l3_rcv(),
the skb already has a conntrack flow attached to it, which means
nf_conntrack_in() will not resolve the flow again.

This means only the dest port is "reverse-NATed" (61033 -> 10000) but
the dest IP remains 2.2.2.2, and since the socket is bound to 1.1.1.1 it's
not received.
This can be verified by logging the 4-tuple of the packet in '__udp4_lib_rcv()'.

The fix is then to reset the flow when skb is received on a VRF, to let
conntrack resolve the flow again (which now will hit the earlier flow).

To reproduce: (Without the fix "Got pkt_to_nat_port" will not be printed by
running 'bash ./repro'):
$ cat run_in_A1.py
import logging
logging.getLogger("scapy.runtime").setLevel(logging.ERROR)
from scapy.all import *
import argparse

def get_packet_to_send(udp_dst_port, msg_name):
return Ether(src='11:22:33:44:55:66', dst=iface_mac)/ \
IP(src='3.3.3.3', dst='2.2.2.2')/ \
UDP(sport=53, dport=udp_dst_port)/ \
Raw(f'{msg_name}\x0012345678901234567890')

parser = argparse.ArgumentParser()
parser.add_argument('-iface_mac', dest="iface_mac", type=str, required=True,
help="From run_in_A3.py")
parser.add_argument('-socket_port', dest="socket_port", type=str,
required=True, help="From run_in_A3.py")
parser.add_argument('-v1_mac', dest="v1_mac", type=str, required=True,
help="From script")

args, _ = parser.parse_known_args()
iface_mac = args.iface_mac
socket_port = int(args.socket_port)
v1_mac = args.v1_mac

print(f'Source port before NAT: {socket_port}')

while True:
pkts = sniff(iface='_v0', store=True, count=1, timeout=10)
if 0 == len(pkts):
print('Something failed, rerun the script :(', flush=True)
break
pkt = pkts[0]
if not pkt.haslayer('UDP'):
continue

pkt_sport = pkt.getlayer('UDP').sport
print(f'Source port after NAT: {pkt_sport}', flush=True)

pkt_to_send = get_packet_to_send(pkt_sport, 'pkt_to_nat_port')
sendp(pkt_to_send, '_v0', verbose=False) # Will not be received

pkt_to_send = get_packet_to_send(socket_port, 'pkt_to_socket_port')
sendp(pkt_to_send, '_v0', verbose=False)
break

$ cat run_in_A2.py
import socket
import netifaces

print(f"{netifaces.ifaddresses('e00000')[netifaces.AF_LINK][0]['addr']}",
flush=True)
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
s.setsockopt(socket.SOL_SOCKET, socket.SO_BINDTODEVICE,
str('vrf_1' + '\0').encode('utf-8'))
s.connect(('3.3.3.3', 53))
print(f'{s. getsockname()[1]}', flush=True)
s.settimeout(5)

while True:
try:
# Periodically send in order to keep the conntrack entry alive.
s.send(b'a'*40)
resp = s.recvfrom(1024)
msg_name = resp[0].decode('utf-8').split('\0')[0]
print(f"Got {msg_name}", flush=True)
except Exception as e:
pass

$ cat repro.sh
ip netns del A1 2> /dev/null
ip netns del A2 2> /dev/null
ip netns add A1
ip netns add A2

ip -n A1 link add _v0 type veth peer name _v1 netns A2
ip -n A1 link set _v0 up

ip -n A2 link add e00000 type bond
ip -n A2 link add lo0 type dummy
ip -n A2 link add vrf_1 type vrf table 10001
ip -n A2 link set vrf_1 up
ip -n A2 link set e00000 master vrf_1

ip -n A2 addr add 1.1.1.1/24 dev e00000
ip -n A2 link set e00000 up
ip -n A2 link set _v1 master e00000
ip -n A2 link set _v1 up
ip -n A2 link set lo0 up
ip -n A2 addr add 2.2.2.2/32 dev lo0

ip -n A2 neigh add 1.1.1.10 lladdr 77:77:77:77:77:77 dev e00000
ip -n A2 route add 3.3.3.3/32 via 1.1.1.10 dev e00000 table 10001

ip netns exec A2 iptables -t nat -A POSTROUTING -p udp -m udp --dport 53 -j \
SNAT --to-source 2.2.2.2 -o vrf_1

sleep 5
ip netns exec A2 python3 run_in_A2.py > x &
XPID=$!
sleep 5

IFACE_MAC=`sed -n 1p x`
SOCKET_PORT=`sed -n 2p x`
V1_MAC=`ip -n A2 link show _v1 | sed -n 2p | awk '{print $2'}`
ip netns exec A1 python3 run_in_A1.py -iface_mac ${IFACE_MAC} -socket_port \
${SOCKET_PORT} -v1_mac ${SOCKET_PORT}
sleep 5

kill -9 $XPID
wait $XPID 2> /dev/null
ip netns del A1
ip netns del A2
tail x -n 2
rm x
set +x

Fixes: 73e20b761acf ("net: vrf: Add support for PREROUTING rules on vrf device")
Signed-off-by: Lahav Schlesinger <lschlesinger@drivenets.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20210815120002.2787653-1-lschlesinger@drivenets.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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vrf: fix NULL dereference in vrf_finish_output()

The "skb" pointer is NULL on this error path so we can't dereference it.
Use "dev" instead.

Fixes: 14ee70ca89e6 ("vrf: use skb_expand_head in vrf_fi

vrf: fix NULL dereference in vrf_finish_output()

The "skb" pointer is NULL on this error path so we can't dereference it.
Use "dev" instead.

Fixes: 14ee70ca89e6 ("vrf: use skb_expand_head in vrf_finish_output")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20210806150435.GB15586@kili
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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