bfd: add per session counters

Add udp total session counts - as stat segment entries:

/bfd/udp4/sessions
/bfd/udp6/sessions

and per session packet/byte counters:

/bfd/rx-session-counters
/bfd/rx-session-echo-counters
/bfd/tx-session-counters
/bfd/tx-session-echo-counters

These counters are per-thread and per-session id.

Adjust tests to verify proper function.

Type: refactor
Signed-off-by: Klement Sekera <klement.sekera@gmail.com>
Change-Id: Ie597928022b6ac74c2220019b9e8e1714295f170
diff --git a/test/test_bfd.py b/test/test_bfd.py
index 7a444cb..174db3e 100644
--- a/test/test_bfd.py
+++ b/test/test_bfd.py
@@ -4,6 +4,7 @@
 from __future__ import division
 
 import binascii
+from collections import namedtuple
 import hashlib
 import ipaddress
 import reprlib
@@ -373,6 +374,10 @@
         self.state = BFDState.down
         self.auth_type = BFDAuthType.no_auth
         self.tunnel_header = tunnel_header
+        self.tx_packets = 0
+        self.rx_packets = 0
+        self.tx_packets_echo = 0
+        self.rx_packets_echo = 0
 
     def inc_seq_num(self):
         """ increment sequence number, wrapping if needed """
@@ -495,6 +500,7 @@
             interface = self.phy_interface
         self.test.logger.debug(ppp("Sending packet:", packet))
         interface.add_stream(packet)
+        self.tx_packets += 1
         self.test.pg_start()
 
     def verify_sha1_auth(self, packet):
@@ -685,6 +691,7 @@
         if time_left < 0:
             raise CaptureTimeoutError("Packet did not arrive within timeout")
         p = test.pg0.wait_for_packet(timeout=time_left)
+        test.test_session.rx_packets += 1
         test.logger.debug(ppp("BFD: Got packet:", p))
         if pcap_time_min is not None and p.time < pcap_time_min:
             test.logger.debug(ppp("BFD: ignoring packet (pcap time %s < "
@@ -707,6 +714,33 @@
     return p
 
 
+BFDStats = namedtuple("BFDStats", "rx rx_echo tx tx_echo")
+
+
+def bfd_grab_stats_snapshot(test, bs_idx=0, thread_index=None):
+    s = test.statistics
+    ti = thread_index
+    if ti is None:
+        rx = s['/bfd/rx-session-counters'][:, bs_idx].sum_packets()
+        rx_echo = s['/bfd/rx-session-echo-counters'][:, bs_idx].sum_packets()
+        tx = s['/bfd/tx-session-counters'][:, bs_idx].sum_packets()
+        tx_echo = s['/bfd/tx-session-echo-counters'][:, bs_idx].sum_packets()
+    else:
+        rx = s['/bfd/rx-session-counters'][ti, bs_idx].sum_packets()
+        rx_echo = s['/bfd/rx-session-echo-counters'][ti, bs_idx].sum_packets()
+        tx = s['/bfd/tx-session-counters'][ti, bs_idx].sum_packets()
+        tx_echo = s['/bfd/tx-session-echo-counters'][ti, bs_idx].sum_packets()
+    return BFDStats(rx, rx_echo, tx, tx_echo)
+
+
+def bfd_stats_diff(stats_before, stats_after):
+    rx = stats_after.rx - stats_before.rx
+    rx_echo = stats_after.rx_echo - stats_before.rx_echo
+    tx = stats_after.tx - stats_before.tx
+    tx_echo = stats_after.tx_echo - stats_before.tx_echo
+    return BFDStats(rx, rx_echo, tx, tx_echo)
+
+
 @tag_run_solo
 class BFD4TestCase(VppTestCase):
     """Bidirectional Forwarding Detection (BFD)"""
@@ -745,6 +779,8 @@
         self.vapi.want_bfd_events()
         self.pg0.enable_capture()
         try:
+            self.bfd_udp4_sessions = self.statistics['/bfd/udp4/sessions']
+            self.bfd_udp6_sessions = self.statistics['/bfd/udp6/sessions']
             self.vpp_session = VppBFDUDPSession(self, self.pg0,
                                                 self.pg0.remote_ip4)
             self.vpp_session.add_vpp_config()
@@ -763,6 +799,10 @@
     def test_session_up(self):
         """ bring BFD session up """
         bfd_session_up(self)
+        bfd_udp4_sessions = self.statistics['/bfd/udp4/sessions']
+        bfd_udp6_sessions = self.statistics['/bfd/udp6/sessions']
+        self.assert_equal(bfd_udp4_sessions - self.bfd_udp4_sessions, 1)
+        self.assert_equal(bfd_udp6_sessions, self.bfd_udp6_sessions)
 
     def test_session_up_by_ip(self):
         """ bring BFD session up - first frame looked up by address pair """
@@ -1121,8 +1161,8 @@
 
     def test_echo_looped_back(self):
         """ echo packets looped back """
-        # don't need a session in this case..
-        self.vpp_session.remove_vpp_config()
+        bfd_session_up(self)
+        stats_before = bfd_grab_stats_snapshot(self)
         self.pg0.enable_capture()
         echo_packet_count = 10
         # random source port low enough to increment a few times..
@@ -1141,7 +1181,10 @@
             self.logger.debug(ppp("Sending packet:", echo_packet))
             self.pg0.add_stream(echo_packet)
             self.pg_start()
-        for dummy in range(echo_packet_count):
+            self.logger.debug(self.vapi.ppcli("show trace"))
+        counter = 0
+        bfd_control_packets_rx = 0
+        while counter < echo_packet_count:
             p = self.pg0.wait_for_packet(1)
             self.logger.debug(ppp("Got packet:", p))
             ether = p[Ether]
@@ -1150,8 +1193,11 @@
             self.assert_equal(self.pg0.local_mac, ether.src, "Source MAC")
             ip = p[IP]
             self.assert_equal(self.pg0.remote_ip4, ip.dst, "Destination IP")
-            self.assert_equal(self.pg0.remote_ip4, ip.src, "Destination IP")
             udp = p[UDP]
+            if udp.dport == BFD.udp_dport:
+                bfd_control_packets_rx += 1
+                continue
+            self.assert_equal(self.pg0.remote_ip4, ip.src, "Source IP")
             self.assert_equal(udp.dport, BFD.udp_dport_echo,
                               "UDP destination port")
             self.assert_equal(udp.sport, udp_sport_rx, "UDP source port")
@@ -1161,11 +1207,23 @@
             self.assertEqual(scapy.compat.raw(p[UDP].payload),
                              scapy.compat.raw(echo_packet[UDP].payload),
                              "Received packet is not the echo packet sent")
+            counter += 1
         self.assert_equal(udp_sport_tx, udp_sport_rx, "UDP source port (== "
                           "ECHO packet identifier for test purposes)")
+        stats_after = bfd_grab_stats_snapshot(self)
+        diff = bfd_stats_diff(stats_before, stats_after)
+        self.assertEqual(
+            0, diff.rx, "RX counter bumped but no BFD packets sent")
+        self.assertEqual(
+            bfd_control_packets_rx, diff.tx, "TX counter incorrect")
+        self.assertEqual(0, diff.rx_echo,
+                         "RX echo counter bumped but no BFD session exists")
+        self.assertEqual(0, diff.tx_echo,
+                         "TX echo counter bumped but no BFD session exists")
 
     def test_echo(self):
         """ echo function """
+        stats_before = bfd_grab_stats_snapshot(self)
         bfd_session_up(self)
         self.test_session.update(required_min_echo_rx=150000)
         self.test_session.send_packet()
@@ -1201,9 +1259,12 @@
                                       "ECHO packet destination MAC address")
                     p[Ether].dst = self.pg0.local_mac
                     self.pg0.add_stream(p)
+                    self.test_session.rx_packets_echo += 1
+                    self.test_session.tx_packets_echo += 1
                     self.pg_start()
                     echo_seen = True
                 elif p.haslayer(BFD):
+                    self.test_session.rx_packets += 1
                     if echo_seen:
                         self.assertGreaterEqual(
                             p[BFD].required_min_rx_interval,
@@ -1220,6 +1281,20 @@
             self.test_session.send_packet()
         self.assertTrue(echo_seen, "No echo packets received")
 
+        stats_after = bfd_grab_stats_snapshot(self)
+        diff = bfd_stats_diff(stats_before, stats_after)
+        # our rx is vpp tx and vice versa, also tolerate one packet off
+        self.assert_in_range(self.test_session.tx_packets,
+                             diff.rx - 1, diff.rx + 1, "RX counter")
+        self.assert_in_range(self.test_session.rx_packets,
+                             diff.tx - 1, diff.tx + 1, "TX counter")
+        self.assert_in_range(self.test_session.tx_packets_echo,
+                             diff.rx_echo - 1, diff.rx_echo + 1,
+                             "RX echo counter")
+        self.assert_in_range(self.test_session.rx_packets_echo,
+                             diff.tx_echo - 1, diff.tx_echo + 1,
+                             "TX echo counter")
+
     def test_echo_fail(self):
         """ session goes down if echo function fails """
         bfd_session_up(self)
@@ -1555,6 +1630,8 @@
         self.vapi.want_bfd_events()
         self.pg0.enable_capture()
         try:
+            self.bfd_udp4_sessions = self.statistics['/bfd/udp4/sessions']
+            self.bfd_udp6_sessions = self.statistics['/bfd/udp6/sessions']
             self.vpp_session = VppBFDUDPSession(self, self.pg0,
                                                 self.pg0.remote_ip6,
                                                 af=AF_INET6)
@@ -1575,6 +1652,10 @@
     def test_session_up(self):
         """ bring BFD session up """
         bfd_session_up(self)
+        bfd_udp4_sessions = self.statistics['/bfd/udp4/sessions']
+        bfd_udp6_sessions = self.statistics['/bfd/udp6/sessions']
+        self.assert_equal(bfd_udp4_sessions, self.bfd_udp4_sessions)
+        self.assert_equal(bfd_udp6_sessions - self.bfd_udp6_sessions, 1)
 
     def test_session_up_by_ip(self):
         """ bring BFD session up - first frame looked up by address pair """
@@ -1614,8 +1695,8 @@
 
     def test_echo_looped_back(self):
         """ echo packets looped back """
-        # don't need a session in this case..
-        self.vpp_session.remove_vpp_config()
+        bfd_session_up(self)
+        stats_before = bfd_grab_stats_snapshot(self)
         self.pg0.enable_capture()
         echo_packet_count = 10
         # random source port low enough to increment a few times..
@@ -1634,7 +1715,9 @@
             self.logger.debug(ppp("Sending packet:", echo_packet))
             self.pg0.add_stream(echo_packet)
             self.pg_start()
-        for dummy in range(echo_packet_count):
+        counter = 0
+        bfd_control_packets_rx = 0
+        while counter < echo_packet_count:
             p = self.pg0.wait_for_packet(1)
             self.logger.debug(ppp("Got packet:", p))
             ether = p[Ether]
@@ -1643,8 +1726,11 @@
             self.assert_equal(self.pg0.local_mac, ether.src, "Source MAC")
             ip = p[IPv6]
             self.assert_equal(self.pg0.remote_ip6, ip.dst, "Destination IP")
-            self.assert_equal(self.pg0.remote_ip6, ip.src, "Destination IP")
             udp = p[UDP]
+            if udp.dport == BFD.udp_dport:
+                bfd_control_packets_rx += 1
+                continue
+            self.assert_equal(self.pg0.remote_ip6, ip.src, "Source IP")
             self.assert_equal(udp.dport, BFD.udp_dport_echo,
                               "UDP destination port")
             self.assert_equal(udp.sport, udp_sport_rx, "UDP source port")
@@ -1654,13 +1740,23 @@
             self.assertEqual(scapy.compat.raw(p[UDP].payload),
                              scapy.compat.raw(echo_packet[UDP].payload),
                              "Received packet is not the echo packet sent")
+            counter += 1
         self.assert_equal(udp_sport_tx, udp_sport_rx, "UDP source port (== "
                           "ECHO packet identifier for test purposes)")
-        self.assert_equal(udp_sport_tx, udp_sport_rx, "UDP source port (== "
-                          "ECHO packet identifier for test purposes)")
+        stats_after = bfd_grab_stats_snapshot(self)
+        diff = bfd_stats_diff(stats_before, stats_after)
+        self.assertEqual(
+            0, diff.rx, "RX counter bumped but no BFD packets sent")
+        self.assertEqual(bfd_control_packets_rx,
+                         diff.tx, "TX counter incorrect")
+        self.assertEqual(0, diff.rx_echo,
+                         "RX echo counter bumped but no BFD session exists")
+        self.assertEqual(0, diff.tx_echo,
+                         "TX echo counter bumped but no BFD session exists")
 
     def test_echo(self):
         """ echo function """
+        stats_before = bfd_grab_stats_snapshot(self)
         bfd_session_up(self)
         self.test_session.update(required_min_echo_rx=150000)
         self.test_session.send_packet()
@@ -1694,11 +1790,14 @@
                     self.logger.debug(ppp("Looping back packet:", p))
                     self.assert_equal(p[Ether].dst, self.pg0.remote_mac,
                                       "ECHO packet destination MAC address")
+                    self.test_session.rx_packets_echo += 1
+                    self.test_session.tx_packets_echo += 1
                     p[Ether].dst = self.pg0.local_mac
                     self.pg0.add_stream(p)
                     self.pg_start()
                     echo_seen = True
                 elif p.haslayer(BFD):
+                    self.test_session.rx_packets += 1
                     if echo_seen:
                         self.assertGreaterEqual(
                             p[BFD].required_min_rx_interval,
@@ -1715,6 +1814,20 @@
             self.test_session.send_packet()
         self.assertTrue(echo_seen, "No echo packets received")
 
+        stats_after = bfd_grab_stats_snapshot(self)
+        diff = bfd_stats_diff(stats_before, stats_after)
+        # our rx is vpp tx and vice versa, also tolerate one packet off
+        self.assert_in_range(self.test_session.tx_packets,
+                             diff.rx - 1, diff.rx + 1, "RX counter")
+        self.assert_in_range(self.test_session.rx_packets,
+                             diff.tx - 1, diff.tx + 1, "TX counter")
+        self.assert_in_range(self.test_session.tx_packets_echo,
+                             diff.rx_echo - 1, diff.rx_echo + 1,
+                             "RX echo counter")
+        self.assert_in_range(self.test_session.rx_packets_echo,
+                             diff.tx_echo - 1, diff.tx_echo + 1,
+                             "TX echo counter")
+
     def test_intf_deleted(self):
         """ interface with bfd session deleted """
         intf = VppLoInterface(self)