make test: improve handling of packet captures

Perform accounting of expected packets based on created packet infos.
Use this accounting info to automatically expect (and verify) the
correct number of packets to be captured. Automatically retry the read
of the capture file if scapy raises an exception while doing so to
handle rare cases when capture file is read while only partially
written during busy wait. Don't fail assert_nothing_captured if only
junk packets arrived.

Change-Id: I16ec2e9410ef510d313ec16b7e13c57d0b2a63f5
Signed-off-by: Klement Sekera <ksekera@cisco.com>

1 files changed, 26 insertions, 29 deletions

diff --git a/test/test_snat.py b/test/test_snat.py
index 8985c3e47dc..ca2e52a7681 100644
--- a/test/test_snat.py
+++ b/test/test_snat.py
@@ -241,7 +241,7 @@ class TestSNAT(VppTestCase):
         self.pg0.add_stream(pkts)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
-        capture = self.pg1.get_capture()
+        capture = self.pg1.get_capture(len(pkts))
         self.verify_capture_out(capture)
 
         # out2in
@@ -249,7 +249,7 @@ class TestSNAT(VppTestCase):
         self.pg1.add_stream(pkts)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
-        capture = self.pg0.get_capture()
+        capture = self.pg0.get_capture(len(pkts))
         self.verify_capture_in(capture, self.pg0)
 
     def test_static_in(self):
@@ -270,7 +270,7 @@ class TestSNAT(VppTestCase):
         self.pg0.add_stream(pkts)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
-        capture = self.pg1.get_capture()
+        capture = self.pg1.get_capture(len(pkts))
         self.verify_capture_out(capture, nat_ip, True)
 
         # out2in
@@ -278,7 +278,7 @@ class TestSNAT(VppTestCase):
         self.pg1.add_stream(pkts)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
-        capture = self.pg0.get_capture()
+        capture = self.pg0.get_capture(len(pkts))
         self.verify_capture_in(capture, self.pg0)
 
     def test_static_out(self):
@@ -299,7 +299,7 @@ class TestSNAT(VppTestCase):
         self.pg1.add_stream(pkts)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
-        capture = self.pg0.get_capture()
+        capture = self.pg0.get_capture(len(pkts))
         self.verify_capture_in(capture, self.pg0)
 
         # in2out
@@ -307,7 +307,7 @@ class TestSNAT(VppTestCase):
         self.pg0.add_stream(pkts)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
-        capture = self.pg1.get_capture()
+        capture = self.pg1.get_capture(len(pkts))
         self.verify_capture_out(capture, nat_ip, True)
 
     def test_static_with_port_in(self):
@@ -333,7 +333,7 @@ class TestSNAT(VppTestCase):
         self.pg0.add_stream(pkts)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
-        capture = self.pg1.get_capture()
+        capture = self.pg1.get_capture(len(pkts))
         self.verify_capture_out(capture)
 
         # out2in
@@ -341,7 +341,7 @@ class TestSNAT(VppTestCase):
         self.pg1.add_stream(pkts)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
-        capture = self.pg0.get_capture()
+        capture = self.pg0.get_capture(len(pkts))
         self.verify_capture_in(capture, self.pg0)
 
     def test_static_with_port_out(self):
@@ -367,7 +367,7 @@ class TestSNAT(VppTestCase):
         self.pg1.add_stream(pkts)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
-        capture = self.pg0.get_capture()
+        capture = self.pg0.get_capture(len(pkts))
         self.verify_capture_in(capture, self.pg0)
 
         # in2out
@@ -375,7 +375,7 @@ class TestSNAT(VppTestCase):
         self.pg0.add_stream(pkts)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
-        capture = self.pg1.get_capture()
+        capture = self.pg1.get_capture(len(pkts))
         self.verify_capture_out(capture)
 
     def test_static_vrf_aware(self):
@@ -401,7 +401,7 @@ class TestSNAT(VppTestCase):
         self.pg4.add_stream(pkts)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
-        capture = self.pg3.get_capture()
+        capture = self.pg3.get_capture(len(pkts))
         self.verify_capture_out(capture, nat_ip1, True)
 
         # inside interface VRF don't match SNAT static mapping VRF (packets
@@ -427,7 +427,7 @@ class TestSNAT(VppTestCase):
         self.pg0.add_stream(pkts)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
-        capture = self.pg3.get_capture()
+        capture = self.pg3.get_capture(len(pkts))
         self.verify_capture_out(capture)
 
         # out2in 1st interface
@@ -435,7 +435,7 @@ class TestSNAT(VppTestCase):
         self.pg3.add_stream(pkts)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
-        capture = self.pg0.get_capture()
+        capture = self.pg0.get_capture(len(pkts))
         self.verify_capture_in(capture, self.pg0)
 
         # in2out 2nd interface
@@ -443,7 +443,7 @@ class TestSNAT(VppTestCase):
         self.pg1.add_stream(pkts)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
-        capture = self.pg3.get_capture()
+        capture = self.pg3.get_capture(len(pkts))
         self.verify_capture_out(capture)
 
         # out2in 2nd interface
@@ -451,7 +451,7 @@ class TestSNAT(VppTestCase):
         self.pg3.add_stream(pkts)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
-        capture = self.pg1.get_capture()
+        capture = self.pg1.get_capture(len(pkts))
         self.verify_capture_in(capture, self.pg1)
 
         # in2out 3rd interface
@@ -459,7 +459,7 @@ class TestSNAT(VppTestCase):
         self.pg2.add_stream(pkts)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
-        capture = self.pg3.get_capture()
+        capture = self.pg3.get_capture(len(pkts))
         self.verify_capture_out(capture)
 
         # out2in 3rd interface
@@ -467,7 +467,7 @@ class TestSNAT(VppTestCase):
         self.pg3.add_stream(pkts)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
-        capture = self.pg2.get_capture()
+        capture = self.pg2.get_capture(len(pkts))
         self.verify_capture_in(capture, self.pg2)
 
     def test_inside_overlapping_interfaces(self):
@@ -485,7 +485,7 @@ class TestSNAT(VppTestCase):
         self.pg4.add_stream(pkts)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
-        capture = self.pg3.get_capture()
+        capture = self.pg3.get_capture(len(pkts))
         self.verify_capture_out(capture)
 
         # out2in 1st interface
@@ -493,7 +493,7 @@ class TestSNAT(VppTestCase):
         self.pg3.add_stream(pkts)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
-        capture = self.pg4.get_capture()
+        capture = self.pg4.get_capture(len(pkts))
         self.verify_capture_in(capture, self.pg4)
 
         # in2out 2nd interface
@@ -501,7 +501,7 @@ class TestSNAT(VppTestCase):
         self.pg5.add_stream(pkts)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
-        capture = self.pg3.get_capture()
+        capture = self.pg3.get_capture(len(pkts))
         self.verify_capture_out(capture)
 
         # out2in 2nd interface
@@ -509,7 +509,7 @@ class TestSNAT(VppTestCase):
         self.pg3.add_stream(pkts)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
-        capture = self.pg5.get_capture()
+        capture = self.pg5.get_capture(len(pkts))
         self.verify_capture_in(capture, self.pg5)
 
         # in2out 3rd interface
@@ -517,7 +517,7 @@ class TestSNAT(VppTestCase):
         self.pg6.add_stream(pkts)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
-        capture = self.pg3.get_capture()
+        capture = self.pg3.get_capture(len(pkts))
         self.verify_capture_out(capture)
 
         # out2in 3rd interface
@@ -525,7 +525,7 @@ class TestSNAT(VppTestCase):
         self.pg3.add_stream(pkts)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
-        capture = self.pg6.get_capture()
+        capture = self.pg6.get_capture(len(pkts))
         self.verify_capture_in(capture, self.pg6)
 
     def test_hairpinning(self):
@@ -553,8 +553,7 @@ class TestSNAT(VppTestCase):
         self.pg0.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
-        capture = self.pg0.get_capture()
-        self.assertEqual(1, len(capture))
+        capture = self.pg0.get_capture(1)
         p = capture[0]
         try:
             ip = p[IP]
@@ -575,8 +574,7 @@ class TestSNAT(VppTestCase):
         self.pg0.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
-        capture = self.pg0.get_capture()
-        self.assertEqual(1, len(capture))
+        capture = self.pg0.get_capture(1)
         p = capture[0]
         try:
             ip = p[IP]
@@ -613,8 +611,7 @@ class TestSNAT(VppTestCase):
         self.pg_start()
 
         # verify number of translated packet
-        capture = self.pg1.get_capture()
-        self.assertEqual(pkts_num, len(capture))
+        self.pg1.get_capture(pkts_num)
 
     def tearDown(self):
         super(TestSNAT, self).tearDown()