[PATCH net-next v2 9/9] selftests: openvswitch: add emit_sample test

[Adrian Moreno]

Add a test to verify sampling packets via psample works.

In order to do that, create a subcommand in ovs-dpctl.py to listen to
on the psample multicast group and print samples.

In order to also test simultaneous sFlow and psample actions and
packet truncation, add missing parsing support for "userspace" and
"trunc" actions.

Signed-off-by: Adrian Moreno <amorenoz@xxxxxxxxxx>
---
 .../selftests/net/openvswitch/openvswitch.sh  |  99 +++++++++++++++-
 .../selftests/net/openvswitch/ovs-dpctl.py    | 112 +++++++++++++++++-
 2 files changed, 204 insertions(+), 7 deletions(-)

diff --git a/tools/testing/selftests/net/openvswitch/openvswitch.sh b/tools/testing/selftests/net/openvswitch/openvswitch.sh
index 5cae53543849..f6e0ae3f6424 100755
--- a/tools/testing/selftests/net/openvswitch/openvswitch.sh
+++ b/tools/testing/selftests/net/openvswitch/openvswitch.sh
@@ -20,7 +20,8 @@ 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
-	drop_reason				drop: test drop reasons are emitted"
+	drop_reason				drop: test drop reasons are emitted
+	emit_sample 				emit_sample: Sampling packets with psample"
 
 info() {
     [ $VERBOSE = 0 ] || echo $*
@@ -170,6 +171,19 @@ ovs_drop_reason_count()
 	return `echo "$perf_output" | grep "$pattern" | wc -l`
 }
 
+ovs_test_flow_fails () {
+	ERR_MSG="Flow actions may not be safe on all matching packets"
+
+	PRE_TEST=$(dmesg | grep -c "${ERR_MSG}")
+	ovs_add_flow $@ &> /dev/null $@ && return 1
+	POST_TEST=$(dmesg | grep -c "${ERR_MSG}")
+
+	if [ "$PRE_TEST" == "$POST_TEST" ]; then
+		return 1
+	fi
+	return 0
+}
+
 usage() {
 	echo
 	echo "$0 [OPTIONS] [TEST]..."
@@ -184,6 +198,89 @@ usage() {
 	exit 1
 }
 
+
+# emit_sample test
+# - use emit_sample to observe packets
+test_emit_sample() {
+	sbx_add "test_emit_sample" || return $?
+
+	# Add a datapath with per-vport dispatching.
+	ovs_add_dp "test_emit_sample" emit_sample -V 2:1 || return 1
+
+	info "create namespaces"
+	ovs_add_netns_and_veths "test_emit_sample" "emit_sample" \
+		client c0 c1 172.31.110.10/24 -u || return 1
+	ovs_add_netns_and_veths "test_emit_sample" "emit_sample" \
+		server s0 s1 172.31.110.20/24 -u || return 1
+
+	# Check if emit_sample actions can be configured.
+	ovs_add_flow "test_emit_sample" emit_sample \
+	'in_port(1),eth(),eth_type(0x0806),arp()' 'emit_sample(group=1)'
+	if [ $? == 1 ]; then
+		info "no support for emit_sample - skipping"
+		ovs_exit_sig
+		return $ksft_skip
+	fi
+
+	ovs_del_flows "test_emit_sample" emit_sample
+
+	# Allow ARP
+	ovs_add_flow "test_emit_sample" emit_sample \
+		'in_port(1),eth(),eth_type(0x0806),arp()' '2' || return 1
+	ovs_add_flow "test_emit_sample" emit_sample \
+		'in_port(2),eth(),eth_type(0x0806),arp()' '1' || return 1
+
+	# Test action verification.
+	OLDIFS=$IFS
+	IFS='*'
+	min_key='in_port(1),eth(),eth_type(0x0800),ipv4()'
+	for testcase in \
+		"cookie to large"*"emit_sample(group=1,cookie=1615141312111009080706050403020100)" \
+		"no group with cookie"*"emit_sample(cookie=abcd)" \
+		"no group"*"sample()";
+	do
+		set -- $testcase;
+		ovs_test_flow_fails "test_emit_sample" emit_sample $min_key $2
+		if [ $? == 1 ]; then
+			info "failed - $1"
+			return 1
+		fi
+	done
+	IFS=$OLDIFS
+
+	# Sample first 14 bytes of all traffic.
+	ovs_add_flow "test_emit_sample" emit_sample \
+	"in_port(1),eth(),eth_type(0x0800),ipv4(src=172.31.110.10,proto=1),icmp()" "trunc(14),emit_sample(group=1,cookie=c0ffee),2"
+
+	# Sample all traffic. In this case, use a sample() action with both
+	# emit_sample and an upcall emulating simultaneous local sampling and
+	# sFlow / IPFIX.
+	nlpid=$(grep -E "listening on upcall packet handler" $ovs_dir/s0.out | cut -d ":" -f 2 | tr -d ' ')
+	ovs_add_flow "test_emit_sample" emit_sample \
+	"in_port(2),eth(),eth_type(0x0800),ipv4(src=172.31.110.20,proto=1),icmp()" "sample(sample=100%,actions(emit_sample(group=2,cookie=eeff0c),userspace(pid=${nlpid},userdata=eeff0c))),1"
+
+	# Record emit_sample data.
+	python3 $ovs_base/ovs-dpctl.py psample >$ovs_dir/psample.out 2>$ovs_dir/psample.err &
+	pid=$!
+	on_exit "ovs_sbx test_emit_sample kill -TERM $pid 2>/dev/null"
+
+	# Send a single ping.
+	sleep 1
+	ovs_sbx "test_emit_sample" ip netns exec client ping -I c1 172.31.110.20 -c 1 || return 1
+	sleep 1
+
+	# We should have received one userspace action upcall and 2 psample packets.
+	grep -E "userspace action command" $ovs_dir/s0.out >/dev/null 2>&1 || return 1
+
+	# client -> server samples should only contain the first 14 bytes of the packet.
+	grep -E "rate:4294967295,group:1,cookie:c0ffee data:[0-9a-f]{28}$" \
+			 $ovs_dir/psample.out >/dev/null 2>&1 || return 1
+	grep -E "rate:4294967295,group:2,cookie:eeff0c" \
+			 $ovs_dir/psample.out >/dev/null 2>&1 || return 1
+
+	return 0
+}
+
 # drop_reason test
 # - drop packets and verify the right drop reason is reported
 test_drop_reason() {
diff --git a/tools/testing/selftests/net/openvswitch/ovs-dpctl.py b/tools/testing/selftests/net/openvswitch/ovs-dpctl.py
index f8b5362aac8c..44fdeb9491a2 100644
--- a/tools/testing/selftests/net/openvswitch/ovs-dpctl.py
+++ b/tools/testing/selftests/net/openvswitch/ovs-dpctl.py
@@ -27,8 +27,10 @@ try:
     from pyroute2.netlink import genlmsg
     from pyroute2.netlink import nla
     from pyroute2.netlink import nlmsg_atoms
-    from pyroute2.netlink.exceptions import NetlinkError
+    from pyroute2.netlink.event import EventSocket
     from pyroute2.netlink.generic import GenericNetlinkSocket
+    from pyroute2.netlink.nlsocket import Marshal
+    from pyroute2.netlink.exceptions import NetlinkError
     import pyroute2
 
 except ModuleNotFoundError:
@@ -575,13 +577,27 @@ class ovsactions(nla):
                 print_str += "userdata="
                 for f in self.get_attr("OVS_USERSPACE_ATTR_USERDATA"):
                     print_str += "%x." % f
-            if self.get_attr("OVS_USERSPACE_ATTR_TUN_PORT") is not None:
+            if self.get_attr("OVS_USERSPACE_ATTR_EGRESS_TUN_PORT") is not None:
                 print_str += "egress_tun_port=%d" % self.get_attr(
-                    "OVS_USERSPACE_ATTR_TUN_PORT"
+                    "OVS_USERSPACE_ATTR_EGRESS_TUN_PORT"
                 )
             print_str += ")"
             return print_str
 
+        def parse(self, actstr):
+            attrs_desc = (
+                ("pid", "OVS_USERSPACE_ATTR_PID", int),
+                ("userdata", "OVS_USERSPACE_ATTR_USERDATA",
+                    lambda x: list(bytearray.fromhex(x))),
+                ("egress_tun_port", "OVS_USERSPACE_ATTR_EGRESS_TUN_PORT", int)
+            )
+
+            attrs, actstr = parse_attrs(actstr, attrs_desc)
+            for attr in attrs:
+                self["attrs"].append(attr)
+
+            return actstr
+
     def dpstr(self, more=False):
         print_str = ""
 
@@ -803,6 +819,25 @@ class ovsactions(nla):
                 self["attrs"].append(["OVS_ACTION_ATTR_EMIT_SAMPLE", emitact])
                 parsed = True
 
+            elif parse_starts_block(actstr, "userspace(", False):
+                uact = self.userspace()
+                actstr = uact.parse(actstr[len("userpsace(") : ])
+                self["attrs"].append(["OVS_ACTION_ATTR_USERSPACE", uact])
+                parsed = True
+
+            elif parse_starts_block(actstr, "trunc", False):
+                parencount += 1
+                actstr, val = parse_extract_field(
+                    actstr,
+                    "trunc(",
+                    r"([0-9]+)",
+                    int,
+                    False,
+                    None,
+                )
+                self["attrs"].append(["OVS_ACTION_ATTR_TRUNC", val])
+                parsed = True
+
             actstr = actstr[strspn(actstr, ", ") :]
             while parencount > 0:
                 parencount -= 1
@@ -2184,10 +2219,70 @@ class OvsFlow(GenericNetlinkSocket):
         print("MISS upcall[%d/%s]: %s" % (seq, pktpres, keystr), flush=True)
 
     def execute(self, packetmsg):
-        print("userspace execute command")
+        print("userspace execute command", flush=True)
 
     def action(self, packetmsg):
-        print("userspace action command")
+        print("userspace action command", flush=True)
+
+
+class psample_sample(genlmsg):
+    nla_map = (
+        ("PSAMPLE_ATTR_IIFINDEX", "none"),
+        ("PSAMPLE_ATTR_OIFINDEX", "none"),
+        ("PSAMPLE_ATTR_ORIGSIZE", "none"),
+        ("PSAMPLE_ATTR_SAMPLE_GROUP", "uint32"),
+        ("PSAMPLE_ATTR_GROUP_SEQ", "none"),
+        ("PSAMPLE_ATTR_SAMPLE_RATE", "uint32"),
+        ("PSAMPLE_ATTR_DATA", "array(uint8)"),
+        ("PSAMPLE_ATTR_GROUP_REFCOUNT", "none"),
+        ("PSAMPLE_ATTR_TUNNEL", "none"),
+        ("PSAMPLE_ATTR_PAD", "none"),
+        ("PSAMPLE_ATTR_OUT_TC", "none"),
+        ("PSAMPLE_ATTR_OUT_TC_OCC", "none"),
+        ("PSAMPLE_ATTR_LATENCY", "none"),
+        ("PSAMPLE_ATTR_TIMESTAMP", "none"),
+        ("PSAMPLE_ATTR_PROTO", "none"),
+        ("PSAMPLE_ATTR_USER_COOKIE", "array(uint8)"),
+    )
+
+    def dpstr(self):
+        fields = []
+        data = ""
+        for (attr, value) in self["attrs"]:
+            if attr == "PSAMPLE_ATTR_SAMPLE_GROUP":
+                fields.append("group:%d" % value)
+            if attr == "PSAMPLE_ATTR_SAMPLE_RATE":
+                fields.append("rate:%d" % value)
+            if attr == "PSAMPLE_ATTR_USER_COOKIE":
+                value = "".join(format(x, "02x") for x in value)
+                fields.append("cookie:%s" % value)
+            if attr == "PSAMPLE_ATTR_DATA" and len(value) > 0:
+                data = "data:%s" % "".join(format(x, "02x") for x in value)
+
+        return ("%s %s" % (",".join(fields), data)).strip()
+
+
+class psample_msg(Marshal):
+    PSAMPLE_CMD_SAMPLE = 0
+    PSAMPLE_CMD_GET_GROUP = 1
+    PSAMPLE_CMD_NEW_GROUP = 2
+    PSAMPLE_CMD_DEL_GROUP = 3
+    PSAMPLE_CMD_SET_FILTER = 4
+    msg_map = {PSAMPLE_CMD_SAMPLE: psample_sample}
+
+
+class Psample(EventSocket):
+    genl_family = "psample"
+    mcast_groups = ["packets"]
+    marshal_class = psample_msg
+
+    def read_samples(self):
+        while True:
+            try:
+                for msg in self.get():
+                    print(msg.dpstr(), flush=True)
+            except NetlinkError as ne:
+                raise ne
 
 
 def print_ovsdp_full(dp_lookup_rep, ifindex, ndb=NDB(), vpl=OvsVport()):
@@ -2247,7 +2342,7 @@ def main(argv):
         help="Increment 'verbose' output counter.",
         default=0,
     )
-    subparsers = parser.add_subparsers()
+    subparsers = parser.add_subparsers(dest="subcommand")
 
     showdpcmd = subparsers.add_parser("show")
     showdpcmd.add_argument(
@@ -2304,6 +2399,8 @@ def main(argv):
     delfscmd = subparsers.add_parser("del-flows")
     delfscmd.add_argument("flsbr", help="Datapath name")
 
+    subparsers.add_parser("psample")
+
     args = parser.parse_args()
 
     if args.verbose > 0:
@@ -2318,6 +2415,9 @@ def main(argv):
 
     sys.setrecursionlimit(100000)
 
+    if args.subcommand == "psample":
+        Psample().read_samples()
+
     if hasattr(args, "showdp"):
         found = False
         for iface in ndb.interfaces:
-- 
2.45.1