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, 46 insertions, 39 deletions

diff --git a/test/test_classifier.py b/test/test_classifier.py
index 0923387cc96..302430f8dff 100644
--- a/test/test_classifier.py
+++ b/test/test_classifier.py
@@ -11,6 +11,7 @@ from scapy.layers.l2 import Ether
 from scapy.layers.inet import IP, UDP
 from util import ppp
 
+
 class TestClassifier(VppTestCase):
     """ Classifier Test Case """
 
@@ -84,8 +85,7 @@ class TestClassifier(VppTestCase):
         """
         pkts = []
         for size in packet_sizes:
-            info = self.create_packet_info(src_if.sw_if_index,
-                                           dst_if.sw_if_index)
+            info = self.create_packet_info(src_if, dst_if)
             payload = self.info_to_payload(info)
             p = (Ether(dst=src_if.local_mac, src=src_if.remote_mac) /
                  IP(src=src_if.remote_ip4, dst=dst_if.remote_ip4) /
@@ -150,8 +150,8 @@ class TestClassifier(VppTestCase):
         :param str dst_port: destination port number <0-ffff>
         """
 
-        return ('{:0>20}{:0>12}{:0>8}{:0>12}{:0>4}'.format(proto, src_ip,
-                dst_ip, src_port, dst_port)).rstrip('0')
+        return ('{:0>20}{:0>12}{:0>8}{:0>12}{:0>4}'.format(
+            proto, src_ip, dst_ip, src_port, dst_port)).rstrip('0')
 
     @staticmethod
     def build_ip_match(proto='', src_ip='', dst_ip='',
@@ -164,11 +164,13 @@ class TestClassifier(VppTestCase):
         :param str src_port: source port number <0-ffff>
         :param str dst_port: destination port number <0-ffff>
         """
-        if src_ip: src_ip = socket.inet_aton(src_ip).encode('hex')
-        if dst_ip: dst_ip = socket.inet_aton(dst_ip).encode('hex')
+        if src_ip:
+            src_ip = socket.inet_aton(src_ip).encode('hex')
+        if dst_ip:
+            dst_ip = socket.inet_aton(dst_ip).encode('hex')
 
-        return ('{:0>20}{:0>12}{:0>8}{:0>12}{:0>4}'.format(proto, src_ip,
-                dst_ip, src_port, dst_port)).rstrip('0')
+        return ('{:0>20}{:0>12}{:0>8}{:0>12}{:0>4}'.format(
+            proto, src_ip, dst_ip, src_port, dst_port)).rstrip('0')
 
     @staticmethod
     def build_mac_mask(dst_mac='', src_mac='', ether_type=''):
@@ -180,7 +182,7 @@ class TestClassifier(VppTestCase):
         """
 
         return ('{:0>12}{:0>12}{:0>4}'.format(dst_mac, src_mac,
-                ether_type)).rstrip('0')
+                                              ether_type)).rstrip('0')
 
     @staticmethod
     def build_mac_match(dst_mac='', src_mac='', ether_type=''):
@@ -190,11 +192,13 @@ class TestClassifier(VppTestCase):
         :param str src_mac: destination MAC address <x:x:x:x:x:x>
         :param str ether_type: ethernet type <0-ffff>
         """
-        if dst_mac: dst_mac = dst_mac.replace(':', '')
-        if src_mac: src_mac = src_mac.replace(':', '')
+        if dst_mac:
+            dst_mac = dst_mac.replace(':', '')
+        if src_mac:
+            src_mac = src_mac.replace(':', '')
 
         return ('{:0>12}{:0>12}{:0>4}'.format(dst_mac, src_mac,
-                ether_type)).rstrip('0')
+                                              ether_type)).rstrip('0')
 
     def create_classify_table(self, key, mask, data_offset=0, is_add=1):
         """Create Classify Table
@@ -206,12 +210,12 @@ class TestClassifier(VppTestCase):
             - create(1) or delete(0)
         """
         r = self.vapi.classify_add_del_table(
-                is_add,
-                binascii.unhexlify(mask),
-                match_n_vectors=(len(mask)-1)//32 + 1,
-                miss_next_index=0,
-                current_data_flag=1,
-                current_data_offset=data_offset)
+            is_add,
+            binascii.unhexlify(mask),
+            match_n_vectors=(len(mask) - 1) // 32 + 1,
+            miss_next_index=0,
+            current_data_flag=1,
+            current_data_offset=data_offset)
         self.assertIsNotNone(r, msg='No response msg for add_del_table')
         self.acl_tbl_idx[key] = r.new_table_index
 
@@ -228,12 +232,12 @@ class TestClassifier(VppTestCase):
             - create(1) or delete(0)
         """
         r = self.vapi.classify_add_del_session(
-                is_add,
-                table_index,
-                binascii.unhexlify(match),
-                opaque_index=0,
-                action=pbr_option,
-                metadata=vrfid)
+            is_add,
+            table_index,
+            binascii.unhexlify(match),
+            opaque_index=0,
+            action=pbr_option,
+            metadata=vrfid)
         self.assertIsNotNone(r, msg='No response msg for add_del_session')
 
     def input_acl_set_interface(self, intf, table_index, is_add=1):
@@ -245,9 +249,9 @@ class TestClassifier(VppTestCase):
             - enable(1) or disable(0)
         """
         r = self.vapi.input_acl_set_interface(
-                is_add,
-                intf.sw_if_index,
-                ip4_table_index=table_index)
+            is_add,
+            intf.sw_if_index,
+            ip4_table_index=table_index)
         self.assertIsNotNone(r, msg='No response msg for acl_set_interface')
 
     def test_acl_ip(self):
@@ -264,14 +268,15 @@ class TestClassifier(VppTestCase):
         self.pg0.add_stream(pkts)
 
         self.create_classify_table('ip', self.build_ip_mask(src_ip='ffffffff'))
-        self.create_classify_session(self.pg0, self.acl_tbl_idx.get('ip'),
-                self.build_ip_match(src_ip=self.pg0.remote_ip4))
+        self.create_classify_session(
+            self.pg0, self.acl_tbl_idx.get('ip'),
+            self.build_ip_match(src_ip=self.pg0.remote_ip4))
         self.input_acl_set_interface(self.pg0, self.acl_tbl_idx.get('ip'))
 
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
 
-        pkts = self.pg1.get_capture()
+        pkts = self.pg1.get_capture(len(pkts))
         self.verify_capture(self.pg1, pkts)
         self.input_acl_set_interface(self.pg0, self.acl_tbl_idx.get('ip'), 0)
         self.pg0.assert_nothing_captured(remark="packets forwarded")
@@ -291,16 +296,17 @@ class TestClassifier(VppTestCase):
         pkts = self.create_stream(self.pg0, self.pg2, self.pg_if_packet_sizes)
         self.pg0.add_stream(pkts)
 
-        self.create_classify_table('mac',
-                self.build_mac_mask(src_mac='ffffffffffff'), data_offset=-14)
-        self.create_classify_session(self.pg0, self.acl_tbl_idx.get('mac'),
-                self.build_mac_match(src_mac=self.pg0.remote_mac))
+        self.create_classify_table(
+            'mac', self.build_mac_mask(src_mac='ffffffffffff'), data_offset=-14)
+        self.create_classify_session(
+            self.pg0, self.acl_tbl_idx.get('mac'),
+            self.build_mac_match(src_mac=self.pg0.remote_mac))
         self.input_acl_set_interface(self.pg0, self.acl_tbl_idx.get('mac'))
 
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
 
-        pkts = self.pg2.get_capture()
+        pkts = self.pg2.get_capture(len(pkts))
         self.verify_capture(self.pg2, pkts)
         self.input_acl_set_interface(self.pg0, self.acl_tbl_idx.get('mac'), 0)
         self.pg0.assert_nothing_captured(remark="packets forwarded")
@@ -322,16 +328,17 @@ class TestClassifier(VppTestCase):
 
         self.create_classify_table('pbr', self.build_ip_mask(src_ip='ffffffff'))
         pbr_option = 1
-        self.create_classify_session(self.pg0, self.acl_tbl_idx.get('pbr'),
-                self.build_ip_match(src_ip=self.pg0.remote_ip4),
-                pbr_option, self.pbr_vrfid)
+        self.create_classify_session(
+            self.pg0, self.acl_tbl_idx.get('pbr'),
+            self.build_ip_match(src_ip=self.pg0.remote_ip4),
+            pbr_option, self.pbr_vrfid)
         self.config_pbr_fib_entry(self.pg3)
         self.input_acl_set_interface(self.pg0, self.acl_tbl_idx.get('pbr'))
 
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
 
-        pkts = self.pg3.get_capture()
+        pkts = self.pg3.get_capture(len(pkts))
         self.verify_capture(self.pg3, pkts)
         self.input_acl_set_interface(self.pg0, self.acl_tbl_idx.get('pbr'), 0)
         self.pg0.assert_nothing_captured(remark="packets forwarded")