On 9/9/25 10:41 AM, Ido Schimmel wrote:

On Fri, Sep 05, 2025 at 03:30:55PM +0200, Ilya Maximets wrote:

...

@@ -220,9 +221,15 @@ static inline struct metadata_dst *ip_tun_rx_dst(struct sk_buff *skb, int md_size) { const struct iphdr *iph = ip_hdr(skb);

• struct metadata_dst *tun_dst;
• tun_dst = __ip_tun_set_dst(iph->saddr, iph->daddr, iph->tos, iph->ttl,

• 		   0, flags, tunnel_id, md_size);
  

• return __ip_tun_set_dst(iph->saddr, iph->daddr, iph->tos, iph->ttl,

• 		0, flags, tunnel_id, md_size);
  

• if (iph->frag_off & htons(IP_DF))

• __set_bit(IP_TUNNEL_DONT_FRAGMENT_BIT,
  

• 	  tun_dst->u.tun_info.key.tun_flags);
  

Shouldn't you check that tun_dst isn't NULL?

That's true. It should be: if (tun_dst && ...) I had too many versions of this change and lost the check in the end.

Will wait a bit and then send a v2.

Thanks!

Best regards, Ilya Maximets.

Ilya Maximets i.maximets@ovn.org writes:

This test ensures that upon receiving decapsulated packets from a tunnel interface in openvswitch, the tunnel metadata fields are properly populated. This partially covers interoperability of the kernel tunnel ports and openvswitch tunnels (LWT) and parsing and formatting of the tunnel metadata fields of the openvswitch netlink uAPI. Doing so, this test also ensures that fields and flags are properly extracted during decapsulation by the tunnel core code, serving as a regression test for the previously fixed issue with the DF bit not being extracted from the outer IP header.

The ovs-dpctl.py script already supports all that is necessary for the tunnel ports for this test, so we only need to adjust the ovs_add_if() function to pass the '-t' port type argument in order to be able to create tunnel ports in the openvswitch datapath.

Signed-off-by: Ilya Maximets i.maximets@ovn.org

Thanks for the test case - it looks good to me. One thing I think would be a useful future enhancement for us is to add json output so that we can use something like 'jq' to parse the upcall output. At the moment, the grep will work, but doesn't let us change anything. But that is work for a future patch.

Reviewed-by: Aaron Conole aconole@redhat.com

.../selftests/net/openvswitch/openvswitch.sh | 88 +++++++++++++++++-- 1 file changed, 81 insertions(+), 7 deletions(-)

diff --git a/tools/testing/selftests/net/openvswitch/openvswitch.sh b/tools/testing/selftests/net/openvswitch/openvswitch.sh index 3c8d3455d8e7..b327d3061ed5 100755 --- a/tools/testing/selftests/net/openvswitch/openvswitch.sh +++ b/tools/testing/selftests/net/openvswitch/openvswitch.sh @@ -25,6 +25,7 @@ tests=" nat_related_v4 ip4-nat-related: ICMP related matches work with SNAT netlink_checks ovsnl: validate netlink attrs and settings upcall_interfaces ovs: test the upcall interfaces

• tunnel_metadata ovs: test extraction of tunnel metadata drop_reason drop: test drop reasons are emitted psample psample: Sampling packets with psample"

@@ -113,13 +114,13 @@ ovs_add_dp () { } ovs_add_if () {

• info "Adding IF to DP: br:$2 if:$3"
• if [ "$4" != "-u" ]; then

• ovs_sbx "$1" python3 $ovs_base/ovs-dpctl.py add-if "$2" "$3" \
  

•     || return 1
  

• info "Adding IF to DP: br:$3 if:$4 ($2)"
• if [ "$5" != "-u" ]; then

• ovs_sbx "$1" python3 $ovs_base/ovs-dpctl.py add-if \
  

•     -t "$2" "$3" "$4" || return 1
  

  else python3 $ovs_base/ovs-dpctl.py add-if \

•     -u "$2" "$3" >$ovs_dir/$3.out 2>$ovs_dir/$3.err &
  

•     -u -t "$2" "$3" "$4" >$ovs_dir/$4.out 2>$ovs_dir/$4.err &
  

  pid=$! on_exit "ovs_sbx $1 kill -TERM $pid 2>/dev/null" fi

@@ -166,9 +167,9 @@ ovs_add_netns_and_veths () { fi if [ "$7" != "-u" ]; then

• ovs_add_if "$1" "$2" "$4" || return 1
  

• ovs_add_if "$1" "netdev" "$2" "$4" || return 1
  

  else

• ovs_add_if "$1" "$2" "$4" -u || return 1
  

• ovs_add_if "$1" "netdev" "$2" "$4" -u || return 1
  

  fi

if [ $TRACING -eq 1 ]; then @@ -756,6 +757,79 @@ test_upcall_interfaces() { return 0 } +ovs_add_kernel_tunnel() {

• local sbxname=$1; shift
• local ns=$1; shift
• local tnl_type=$1; shift
• local name=$1; shift
• local addr=$1; shift
• info "setting up kernel ${tnl_type} tunnel ${name}"
• ovs_sbx "${sbxname}" ip -netns ${ns} link add dev ${name} type ${tnl_type} $* || return 1
• on_exit "ovs_sbx ${sbxname} ip -netns ${ns} link del ${name} >/dev/null 2>&1"
• ovs_sbx "${sbxname}" ip -netns ${ns} addr add dev ${name} ${addr} || return 1
• ovs_sbx "${sbxname}" ip -netns ${ns} link set dev ${name} mtu 1450 up || return 1

+}

+test_tunnel_metadata() {

• which arping >/dev/null 2>&1 || return $ksft_skip
• sbxname="test_tunnel_metadata"
• sbx_add "${sbxname}" || return 1
• info "setting up new DP"
• ovs_add_dp "${sbxname}" tdp0 -V 2:1 || return 1
• ovs_add_netns_and_veths "${sbxname}" tdp0 tns left0 l0 \

• 172.31.110.1/24 || return 1
  

• info "removing veth interface from openvswitch and setting IP"
• ovs_del_if "${sbxname}" tdp0 left0 || return 1
• ovs_sbx "${sbxname}" ip addr add 172.31.110.2/24 dev left0 || return 1
• ovs_sbx "${sbxname}" ip link set left0 up || return 1
• info "setting up tunnel port in openvswitch"
• ovs_add_if "${sbxname}" "vxlan" tdp0 ovs-vxlan0 -u || return 1
• on_exit "ovs_sbx ${sbxname} ip link del ovs-vxlan0"
• ovs_wait ip link show ovs-vxlan0 &>/dev/null || return 1
• ovs_sbx "${sbxname}" ip link set ovs-vxlan0 up || return 1
• configs=$(echo '

•    1 172.31.221.1/24 1155332 32   set   udpcsum flags\(df\|csum\)
  

•    2 172.31.222.1/24 1234567 45   set noudpcsum flags\(df\)
  

•    3 172.31.223.1/24 1020304 23 unset   udpcsum flags\(csum\)
  

•    4 172.31.224.1/24 1357986 15 unset noudpcsum' | sed '/^$/d')
  

• while read -r i addr id ttl df csum flags; do

• ovs_add_kernel_tunnel "${sbxname}" tns vxlan vxlan${i} ${addr} \
  

• 	remote 172.31.110.2 id ${id} dstport 4789 \
  

• 	ttl ${ttl} df ${df} ${csum} || return 1
  

• done <<< "${configs}"
• ovs_wait grep -q 'listening on upcall packet handler' \

• ${ovs_dir}/ovs-vxlan0.out || return 1
  

• info "sending arping"
• for i in 1 2 3 4; do

• ovs_sbx "${sbxname}" ip netns exec tns \
  

• 	arping -I vxlan${i} 172.31.22${i}.2 -c 1 \
  

• 	>${ovs_dir}/arping.stdout 2>${ovs_dir}/arping.stderr
  

• done
• info "checking that received decapsulated packets carry correct metadata"
• while read -r i addr id ttl df csum flags; do

• arp_hdr="arp\\(sip=172.31.22${i}.1,tip=172.31.22${i}.2,op=1,sha="
  

• addrs="src=172.31.110.1,dst=172.31.110.2"
  

• ports="tp_src=[0-9]*,tp_dst=4789"
  

• tnl_md="tunnel\\(tun_id=${id},${addrs},ttl=${ttl},${ports},${flags}\\)"
  

• ovs_sbx "${sbxname}" grep -qE "MISS upcall.*${tnl_md}.*${arp_hdr}" \
  

• 	${ovs_dir}/ovs-vxlan0.out || return 1
  

• done <<< "${configs}"
• return 0

+}

run_test() { ( tname="$1"