linux-stable.git/drivers/net/vrf.c, branch linux-5.4.y

vrf: Drop existing dst reference in vrf_ip6_input_dst

2025-08-28T14:21:20+00:00

[ Upstream commit f388f807eca1de9e6e70f9ffb1a573c3811c4215 ]

Commit ff3fbcdd4724 ("selftests: tc: Add generic erspan_opts matching support
for tc-flower") started triggering the following kmemleak warning:

unreferenced object 0xffff888015fb0e00 (size 512):
  comm "softirq", pid 0, jiffies 4294679065
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 40 d2 85 9e ff ff ff ff  ........@.......
    41 69 59 9d ff ff ff ff 00 00 00 00 00 00 00 00  AiY.............
  backtrace (crc 30b71e8b):
    __kmalloc_noprof+0x359/0x460
    metadata_dst_alloc+0x28/0x490
    erspan_rcv+0x4f1/0x1160 [ip_gre]
    gre_rcv+0x217/0x240 [ip_gre]
    gre_rcv+0x1b8/0x400 [gre]
    ip_protocol_deliver_rcu+0x31d/0x3a0
    ip_local_deliver_finish+0x37d/0x620
    ip_local_deliver+0x174/0x460
    ip_rcv+0x52b/0x6b0
    __netif_receive_skb_one_core+0x149/0x1a0
    process_backlog+0x3c8/0x1390
    __napi_poll.constprop.0+0xa1/0x390
    net_rx_action+0x59b/0xe00
    handle_softirqs+0x22b/0x630
    do_softirq+0xb1/0xf0
    __local_bh_enable_ip+0x115/0x150

vrf_ip6_input_dst unconditionally sets skb dst entry, add a call to
skb_dst_drop to drop any existing entry.

Cc: David Ahern 
Reviewed-by: Ido Schimmel 
Fixes: 9ff74384600a ("net: vrf: Handle ipv6 multicast and link-local addresses")
Signed-off-by: Stanislav Fomichev 
Link: https://patch.msgid.link/20250725160043.350725-1-sdf@fomichev.me
Signed-off-by: Jakub Kicinski 
Signed-off-by: Sasha Levin

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

2021-12-14T13:48:59+00:00

commit d43b75fbc23f0ac1ef9c14a5a166d3ccb761a451 upstream.

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 
Acked-by: Florian Westphal 
Reviewed-by: David Ahern 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman

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

2021-12-08T08:01:10+00:00

commit ee201011c1e1563c114a55c86eb164b236f18e84 upstream.

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  dev " 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 
Reviewed-by: David Ahern 
Link: https://lore.kernel.org/r/20211130162637.3249-1-ssuryaextr@gmail.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Greg Kroah-Hartman

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

2021-11-17T08:48:32+00:00

[ Upstream commit 8c9c296adfae9ea05f655d69e9f6e13daa86fb4a ]

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 
Acked-by: David Ahern 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

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

2021-11-06T12:59:44+00:00

commit 55161e67d44fdd23900be166a81e996abd6e3be9 upstream.

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 
Acked-by: David Ahern 
Signed-off-by: David S. Miller 
Cc: Florian Westphal 
Signed-off-by: Greg Kroah-Hartman

vrf: Reset skb conntrack connection on VRF rcv

2021-08-26T12:36:18+00:00

[ Upstream commit 09e856d54bda5f288ef8437a90ab2b9b3eab83d1 ]

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 
Reviewed-by: David Ahern 
Link: https://lore.kernel.org/r/20210815120002.2787653-1-lschlesinger@drivenets.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Sasha Levin

vrf: do not push non-ND strict packets with a source LLA through packet taps again

2021-07-14T14:53:31+00:00

[ Upstream commit 603113c514e95c3350598bc3cccbd03af7ea4ab2 ]

Non-ND strict packets with a source LLA go through the packet taps
again, while non-ND strict packets with other source addresses do not,
and we can see a clone of those packets on the vrf interface (we should
not). This is due to a series of changes:

Commit 6f12fa775530[1] made non-ND strict packets not being pushed again
in the packet taps. This changed with commit 205704c618af[2] for those
packets having a source LLA, as they need a lookup with the orig_iif.

The issue now is those packets do not skip the 'vrf_ip6_rcv' function to
the end (as the ones without a source LLA) and go through the check to
call packet taps again. This check was changed by commit 6f12fa775530[1]
and do not exclude non-strict packets anymore. Packets matching
'need_strict && !is_ndisc && is_ll_src' are now being sent through the
packet taps again. This can be seen by dumping packets on the vrf
interface.

Fix this by having the same code path for all non-ND strict packets and
selectively lookup with the orig_iif for those with a source LLA. This
has the effect to revert to the pre-205704c618af[2] condition, which
should also be easier to maintain.

[1] 6f12fa775530 ("vrf: mark skb for multicast or link-local as enslaved to VRF")
[2] 205704c618af ("vrf: packets with lladdr src needs dst at input with orig_iif when needs strict")

Fixes: 205704c618af ("vrf: packets with lladdr src needs dst at input with orig_iif when needs strict")
Cc: Stephen Suryaputra 
Reported-by: Paolo Abeni 
Signed-off-by: Antoine Tenart 
Reviewed-by: David Ahern 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

vrf: fix maximum MTU

2021-06-23T12:41:24+00:00

[ Upstream commit 9bb392f62447d73cc7dd7562413a2cd9104c82f8 ]

My initial goal was to fix the default MTU, which is set to 65536, ie above
the maximum defined in the driver: 65535 (ETH_MAX_MTU).

In fact, it's seems more consistent, wrt min_mtu, to set the max_mtu to
IP6_MAX_MTU (65535 + sizeof(struct ipv6hdr)) and use it by default.

Let's also, for consistency, set the mtu in vrf_setup(). This function
calls ether_setup(), which set the mtu to 1500. Thus, the whole mtu config
is done in the same function.

Before the patch:
$ ip link add blue type vrf table 1234
$ ip link list blue
9: blue:  mtu 65536 qdisc noop state DOWN mode DEFAULT group default qlen 1000
    link/ether fa:f5:27:70:24:2a brd ff:ff:ff:ff:ff:ff
$ ip link set dev blue mtu 65535
$ ip link set dev blue mtu 65536
Error: mtu greater than device maximum.

Fixes: 5055376a3b44 ("net: vrf: Fix ping failed when vrf mtu is set to 0")
CC: Miaohe Lin 
Signed-off-by: Nicolas Dichtel 
Reviewed-by: David Ahern 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

vrf: packets with lladdr src needs dst at input with orig_iif when needs strict

2020-12-21T12:27:03+00:00

[ Upstream commit 205704c618af0ab2366015d2281a3b0814d918a0 ]

Depending on the order of the routes to fe80::/64 are installed on the
VRF table, the NS for the source link-local address of the originator
might be sent to the wrong interface.

This patch ensures that packets with link-local addr source is doing a
lookup with the orig_iif when the destination addr indicates that it
is strict.

Add the reproducer as a use case in self test script fcnal-test.sh.

Fixes: b4869aa2f881 ("net: vrf: ipv6 support for local traffic to local addresses")
Signed-off-by: Stephen Suryaputra 
Reviewed-by: David Ahern 
Link: https://lore.kernel.org/r/20201204030604.18828-1-ssuryaextr@gmail.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Greg Kroah-Hartman

vrf: Fix fast path output packet handling with async Netfilter rules

2020-11-18T18:20:28+00:00

[ Upstream commit 9e2b7fa2df4365e99934901da4fb4af52d81e820 ]

VRF devices use an optimized direct path on output if a default qdisc
is involved, calling Netfilter hooks directly. This path, however, does
not consider Netfilter rules completing asynchronously, such as with
NFQUEUE. The Netfilter okfn() is called for asynchronously accepted
packets, but the VRF never passes that packet down the stack to send
it out over the slave device. Using the slower redirect path for this
seems not feasible, as we do not know beforehand if a Netfilter hook
has asynchronously completing rules.

Fix the use of asynchronously completing Netfilter rules in OUTPUT and
POSTROUTING by using a special completion function that additionally
calls dst_output() to pass the packet down the stack. Also, slightly
adjust the use of nf_reset_ct() so that is called in the asynchronous
case, too.

Fixes: dcdd43c41e60 ("net: vrf: performance improvements for IPv4")
Fixes: a9ec54d1b0cd ("net: vrf: performance improvements for IPv6")
Signed-off-by: Martin Willi 
Link: https://lore.kernel.org/r/20201106073030.3974927-1-martin@strongswan.org
Signed-off-by: Jakub Kicinski 
Signed-off-by: Sasha Levin