Remove some unnecessary imports of Scapy module (#5128)

Signed-off-by: Andy Fingerhut <andy_fingerhut@alum.wustl.edu>

backends/bmv2/bmv2stf.py

@@ -907,7 +907,7 @@ def checkOutputs(self) -> int:
                 # We only care that the packet was received on this particular port.
                 if not expected_pkt:
                     continue
-                cmp_result = testutils.compare_pkt(expected_pkt, packets[idx])
+                cmp_result = testutils.compare_pkt(expected_pkt, packets[idx].build())
                 if cmp_result != testutils.SUCCESS:
                     testutils.log.error("Packet %s on port %s differs", idx, interface)
                     return cmp_result

backends/bmv2/run-bmv2-test.py

@@ -137,8 +137,6 @@
 sys.path.append(str(ROOT_DIR))
 
 from bmv2stf import Options, RunBMV2
-from scapy.layers.all import *
-from scapy.utils import *
 
 from tools import testutils  # pylint: disable=wrong-import-position
 

backends/ebpf/targets/target.py

@@ -208,7 +208,7 @@ def check_outputs(self):
                 )
                 return testutils.FAILURE
             for idx, expected_pkt in enumerate(expected):
-                cmp = testutils.compare_pkt(expected_pkt, packets[idx])
+                cmp = testutils.compare_pkt(expected_pkt, packets[idx].build())
                 if cmp != testutils.SUCCESS:
                     testutils.log.error("Packet %s on port %s differs", idx, interface)
                     return cmp

tools/testutils.py

@@ -27,8 +27,6 @@
 from pathlib import Path
 from typing import Any, Dict, List, NamedTuple, Optional, Union
 
-import scapy.packet
-
 # Set up logging.
 log = logging.getLogger(__name__)
 
@@ -93,7 +91,7 @@ def hex_to_byte(hex_str: str) -> str:
     return "".join(byte_vals)
 
 
-def compare_pkt(expected: str, received: scapy.packet.Packet) -> int:
+def compare_pkt(expected: str, received: bytes) -> int:
     """Compare two given byte sequences and check if they are the same.
     Report errors if this is not the case."""
 
@@ -104,7 +102,7 @@ def compare_pkt(expected: str, received: scapy.packet.Packet) -> int:
         strict_length_check = True
         expected = expected[:-1]
 
-    received = received.build().hex().upper()
+    received = received.hex().upper()
     expected = "".join(expected.split()).upper()
     if strict_length_check and len(received) > len(expected):
         log.error(