Re: [PATCH net-next] selftests/net/openvswitch: add SCTP flow key test

[Aaron Conole <aconole@redhat.com>]

Hi Minxi,

Minxi Hou <houminxi@gmail.com> writes:

> Register OVS_KEY_ATTR_SCTP in the flow key parser so that sctp()
> can be used in flow specifications. The ovs_key_sctp class already
> exists (with src/dst fields matching the TCP/UDP siblings) but was
> not wired into the parser, so the token was silently dropped and the
> kernel rejected the flow.
>
> Add test_sctp_connect_v4 exercising the SCTP flow key with
> port-specific matching: sctp(dst=4443) for client-to-server and
> sctp(src=4443) for server-to-client, mirroring the SCTP four-way
> handshake direction. The test verifies connectivity with flows
> installed, confirms failure after flow removal, then reinstalls
> and verifies recovery.
>
> Signed-off-by: Minxi Hou <houminxi@gmail.com>
> ---

One issue I think will happen with this patch is that the other two
in-flight patches will also collide.  I'm thinking it may require
rebasing.

A better strategy going forward would be to bundle the new test
additions in one series.  That's just for going forward, do not resubmit
the existing patches I've acked unless a maintainer asks for it.

>  .../selftests/net/openvswitch/openvswitch.sh  | 92 +++++++++++++++++++
>  .../selftests/net/openvswitch/ovs-dpctl.py    |  5 +
>  2 files changed, 97 insertions(+)
>
> diff --git a/tools/testing/selftests/net/openvswitch/openvswitch.sh b/tools/testing/selftests/net/openvswitch/openvswitch.sh
> index 2954245129a2..dd4d0b3bcc23 100755
> --- a/tools/testing/selftests/net/openvswitch/openvswitch.sh
> +++ b/tools/testing/selftests/net/openvswitch/openvswitch.sh
> @@ -32,6 +32,7 @@ tests="
>  	dec_ttl					ttl: dec_ttl decrements IP TTL
>  	flow_set				flow-set: Flow modify
>  	action_set				set: SET action rewrites fields
> +	sctp_connect_v4				sctp: SCTP flow key matching
>  	psample					psample: Sampling packets with psample"
>  
>  info() {
> @@ -443,6 +444,97 @@ test_action_set() {
>  	return 0
>  }
>  
> +# sctp_connect_v4 test
> +# - sctp(dst=4443) matches client-to-server INIT
> +# - sctp(src=4443) matches server-to-client INIT-ACK
> +# - remove flows and verify connection fails, reinstall and recover
> +test_sctp_connect_v4() {
> +	local t="test_sctp_connect_v4"
> +	which ncat >/dev/null 2>&1 || return $ksft_skip
> +	modprobe -q sctp 2>/dev/null || return $ksft_skip
> +
> +	sbx_add "$t" || return $?
> +	ovs_add_dp "$t" sctp4 || return 1
> +
> +	info "create namespaces"
> +	for ns in client server; do
> +		ovs_add_netns_and_veths "$t" "sctp4" "$ns" \
> +		    "${ns:0:1}0" "${ns:0:1}1" || return 1
> +	done
> +
> +	ip netns exec client ip addr add 172.31.110.10/24 dev c1
> +	ip netns exec client ip link set c1 up
> +	ip netns exec server ip addr add 172.31.110.20/24 dev s1
> +	ip netns exec server ip link set s1 up
> +
> +	# ARP forwarding
> +	ovs_add_flow "$t" sctp4 \
> +	    'in_port(1),eth(),eth_type(0x0806),arp()' \
> +	    '2' || return 1
> +	ovs_add_flow "$t" sctp4 \
> +	    'in_port(2),eth(),eth_type(0x0806),arp()' \
> +	    '1' || return 1
> +
> +	# SCTP port matching: dst for request, src for reply
> +	ovs_add_flow "$t" sctp4 \
> +	    'in_port(1),eth(),eth_type(0x0800),ipv4(proto=132),sctp(dst=4443)' \
> +	    '2' || return 1
> +	ovs_add_flow "$t" sctp4 \
> +	    'in_port(2),eth(),eth_type(0x0800),ipv4(proto=132),sctp(src=4443)' \
> +	    '1' || return 1
> +
> +	echo "server" | \
> +		ovs_netns_spawn_daemon "$t" "server" \
> +				ncat --sctp -l 172.31.110.20 -vn 4443
> +	sleep 0.1

Instead of this pattern, we can probably do an ovs_wait on the Listening
string.  That way we aren't relying only on the sleep, but on the actual
Ncat output.  Something like

   ovs_wait sh -c
     "[ \$(grep 'Ncat: Listening on ....' ${ovs_dir}/stderr) ]" || \
     return 1

Or you could use a count and do '-ge <number>'

That way if the ncat spawn takes time to start up, it can be ready in
time.

> +	info "verify SCTP association with port-keyed flows"
> +	ovs_sbx "$t" ip netns exec client \
> +	    ncat --sctp -i 1 -zv 172.31.110.20 4443 \
> +	    || return 1
> +
> +	ovs_del_flows "$t" sctp4
> +
> +	info "verify connection fails without flows"
> +	ovs_add_flow "$t" sctp4 \
> +	    'in_port(1),eth(),eth_type(0x0806),arp()' \
> +	    '2' || return 1
> +	ovs_add_flow "$t" sctp4 \
> +	    'in_port(2),eth(),eth_type(0x0806),arp()' \
> +	    '1' || return 1
> +
> +	echo "server2" | \
> +		ovs_netns_spawn_daemon "$t" "server" \
> +				ncat --sctp -l 172.31.110.20 -vn 4443
> +	sleep 0.1
> +
> +	ovs_sbx "$t" ip netns exec client \
> +	    ncat --sctp -w 2 -zv 172.31.110.20 4443 \
> +	    >/dev/null 2>&1 \
> +	    && { info "FAIL: connection should fail without flows"
> +	         return 1; }
> +
> +	info "reinstall flows and verify recovery"
> +	ovs_add_flow "$t" sctp4 \
> +	    'in_port(1),eth(),eth_type(0x0800),ipv4(proto=132),sctp(dst=4443)' \
> +	    '2' || return 1
> +	ovs_add_flow "$t" sctp4 \
> +	    'in_port(2),eth(),eth_type(0x0800),ipv4(proto=132),sctp(src=4443)' \
> +	    '1' || return 1
> +
> +	echo "server3" | \
> +		ovs_netns_spawn_daemon "$t" "server" \
> +				ncat --sctp -l 172.31.110.20 -vn 4443
> +	sleep 0.1
> +
> +	ovs_sbx "$t" ip netns exec client \
> +	    ncat --sctp -i 1 -zv 172.31.110.20 4443 \
> +	    || return 1
> +
> +	return 0
> +}
> +
>  # psample test
>  # - use psample to observe packets
>  test_psample() {
> diff --git a/tools/testing/selftests/net/openvswitch/ovs-dpctl.py b/tools/testing/selftests/net/openvswitch/ovs-dpctl.py
> index e1ecfad2c03e..7cfc29ec7e59 100644
> --- a/tools/testing/selftests/net/openvswitch/ovs-dpctl.py
> +++ b/tools/testing/selftests/net/openvswitch/ovs-dpctl.py
> @@ -1982,6 +1982,11 @@ class ovskey(nla):
>                  "icmp",
>                  ovskey.ovs_key_icmp,
>              ),
> +            (
> +                "OVS_KEY_ATTR_SCTP",
> +                "sctp",
> +                ovskey.ovs_key_sctp,
> +            ),
>              (
>                  "OVS_KEY_ATTR_TCP_FLAGS",
>                  "tcp_flags",