Re-add some minor SMB2 tets

Author: gpotter2

scapy/layers/smb2.py

@@ -8,7 +8,7 @@
 """
 
 from scapy.config import conf
-from scapy.packet import Packet, bind_layers
+from scapy.packet import Packet, bind_layers, bind_top_down
 from scapy.fields import (
     FieldLenField,
     FieldListField,
@@ -296,6 +296,18 @@ class SMB2_Negociate_Protocol_Response_Header(Packet):
 bind_layers(SMB2_Encryption_Capabilities, conf.padding_layer)
 bind_layers(SMB2_Compression_Capabilities, conf.padding_layer)
 bind_layers(SMB2_Netname_Negociate_Context_ID, conf.padding_layer)
+bind_top_down(
+    SMB2_Header,
+    SMB2_Negociate_Protocol_Request_Header,
+    Command=0x0000,
+    Flags=0
+)
+bind_top_down(
+    SMB2_Header,
+    SMB2_Negociate_Protocol_Response_Header,
+    Command=0x0000,
+    Flags=2 ** 24  # SMB2_FLAGS_SERVER_TO_REDIR
+)
 bind_layers(
     SMB2_Negociate_Context,
     SMB2_Preauth_Integrity_Capabilities,

test/smb2.uts

@@ -132,6 +132,11 @@ assert netname.ContextType == 0x5
 assert netname.DataLength == 28
 assert netname.NetName == '192.168.178.21'
 
+= test SMB2 Negociate Protocol Request Header - assembling
+
+pkt = IP() / TCP() / NBTSession() / SMB2_Header() / SMB2_Negociate_Protocol_Request_Header()
+pkt = IP(raw(pkt))
+assert SMB2_Negociate_Protocol_Request_Header in pkt
 
 + SMB2 Negociate Protocol Response Header dissecting
 
@@ -194,3 +199,8 @@ assert comp.CompressionAlgorithmCount == 1
 assert len(comp.CompressionAlgorithms) == 1
 assert comp.CompressionAlgorithms[0] == 1
 
+= SMB2 Negociate Protocol Response Header assembling
+
+pkt = IP() / TCP() / NBTSession() / SMB2_Header() / SMB2_Negociate_Protocol_Response_Header()
+pkt = IP(raw(pkt))
+assert SMB2_Negociate_Protocol_Response_Header in pkt