Merge pull request #3030 from secdev/guedou/issue_3018

Missing Python3 compatible conversion

Author: p-l-

scapy/contrib/icmp_extensions.py

@@ -19,6 +19,7 @@
 import struct
 
 import scapy
+from scapy.compat import chb
 from scapy.packet import Packet, bind_layers
 from scapy.fields import BitField, ByteField, ConditionalField, \
     FieldLenField, IPField, IntField, PacketListField, ShortField, \
@@ -55,7 +56,7 @@ class ICMPExtensionHeader(Packet):
     def post_build(self, p, pay):
         if self.chksum is None:
             ck = checksum(p)
-            p = p[:2] + chr(ck >> 8) + chr(ck & 0xff) + p[4:]
+            p = p[:2] + chb(ck >> 8) + chb(ck & 0xff) + p[4:]
         return p + pay
 
     def guess_payload_class(self, payload):

test/contrib/icmp_extensions.uts

@@ -0,0 +1,8 @@
++ ICMP Extensions tests
+
+= Basic build
+
+p = IP(src="192.0.2.1", dst="192.0.2.2")/ICMP()/ICMPExtensionHeader(version = 2)/ICMPExtensionMPLS(classnum = 1, classtype = 1)
+print(raw(p))
+b = b'E\x00\x00$\x00\x01\x00\x00@\x01\xf6\xd4\xc0\x00\x02\x01\xc0\x00\x02\x02\x08\x00\xf6\xfa\x00\x00\x00\x00 \x00\xdf\xff\x00\x04\x01\x01'
+assert raw(p) == b