DHCPv6: add RFC9686 support (#4694)

This adds 2 new DHCPv6 messages and 1 new DHCPv6 option

 - ADDR-REG-INFORM message added
 - ADDR-REG-REPLY message added
 - ADDR-REG option added
 - Flake8 appeased
 - Unit-tests added

Author: tomaszmrugalski

scapy/layers/dhcp6.py

@@ -57,7 +57,10 @@ def get_cls(name, fallback_cls):
                      10: "DHCP6_Reconf",
                      11: "DHCP6_InfoRequest",
                      12: "DHCP6_RelayForward",
-                     13: "DHCP6_RelayReply"}
+                     13: "DHCP6_RelayReply",
+                     36: "DHCP6_AddrRegInform",
+                     37: "DHCP6_AddrRegReply",
+                     }
 
 
 def _dhcp6_dispatcher(x, *args, **kargs):
@@ -128,6 +131,7 @@ def _dhcp6_dispatcher(x, *args, **kargs):
              79: "OPTION_CLIENT_LINKLAYER_ADDR",  # RFC6939
              103: "OPTION_CAPTIVE_PORTAL",  # RFC8910
              112: "OPTION_MUD_URL",  # RFC8520
+             148: "OPTION_ADDR_REG_ENABLE",  # RFC9686
              }
 
 dhcp6opts_by_code = {1: "DHCP6OptClientId",
@@ -187,10 +191,12 @@ def _dhcp6_dispatcher(x, *args, **kargs):
                      79: "DHCP6OptClientLinkLayerAddr",  # RFC6939
                      103: "DHCP6OptCaptivePortal",  # RFC8910
                      112: "DHCP6OptMudUrl",  # RFC8520
+                     148: "DHCP6OptAddrRegEnable",  # RFC9686
                      }
 
 
 # sect 7.3 RFC 8415 : DHCP6 Messages types
+# also RFC 9686
 dhcp6types = {1: "SOLICIT",
                  2: "ADVERTISE",
                  3: "REQUEST",
@@ -203,7 +209,10 @@ def _dhcp6_dispatcher(x, *args, **kargs):
               10: "RECONFIGURE",
               11: "INFORMATION-REQUEST",
               12: "RELAY-FORW",
-              13: "RELAY-REPL"}
+              13: "RELAY-REPL",
+              36: "ADDR-REG-INFORM",
+              37: "ADDR-REG-REPLY",
+              }
 
 
 #####################################################################
@@ -1103,6 +1112,12 @@ class DHCP6OptMudUrl(_DHCP6OptGuessPayload):  # RFC8520
                                )]
 
 
+class DHCP6OptAddrRegEnable(_DHCP6OptGuessPayload):   # RFC 9686 sect 4.1
+    name = "DHCP6 Address Registration Option"
+    fields_desc = [ShortEnumField("optcode", 148, dhcp6opts),
+                   ShortField("optlen", 0)]
+
+
 #####################################################################
 #                          DHCPv6 messages                          #
 #####################################################################
@@ -1437,6 +1452,24 @@ def answers(self, other):
                 self.peeraddr == other.peeraddr)
 
 
+#####################################################################
+# Address Registration-Inform Message (RFC 9686)
+# - sent by clients who generated their own address and need it registered
+
+class DHCP6_AddrRegInform(DHCP6):
+    name = "DHCPv6 Information Request Message"
+    msgtype = 36
+
+#####################################################################
+# Address Registration-Reply Message (RFC 9686)
+# - sent by servers who respond to the address registration-inform message
+
+
+class DHCP6_AddrRegReply(DHCP6):
+    name = "DHCPv6 Information Reply Message"
+    msgtype = 37
+
+
 bind_bottom_up(UDP, _dhcp6_dispatcher, {"dport": 547})
 bind_bottom_up(UDP, _dhcp6_dispatcher, {"dport": 546})
 

test/scapy/layers/dhcp6.uts

@@ -1310,6 +1310,19 @@ p = DHCP6OptVSS(s)
 assert p.type == 255
 
 
+############
+############
++ Test DHCP6 Option - Address Registration Enabled
+
+= DHCP6OptAddrRegEnable - Basic Instantiation
+raw(DHCP6OptAddrRegEnable()) == b'\x00\x94\x00\x00'
+
+= DHCP6OptAddrRegEnable - Basic Dissection
+a=DHCP6OptAddrRegEnable(b'\x00\x94\x00\x00')
+a.optcode == 148 and a.optlen == 0
+
+
+
 ############
 ############
 + Test DHCP6 Messages - DHCP6_Solicit
@@ -1564,4 +1577,52 @@ raw(DHCP6_RelayReply()) == b'\r\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\
 a=DHCP6_RelayReply(b'\r\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00')
 a.msgtype == 13 and a.hopcount == 0 and a.linkaddr == "::" and a.peeraddr == "::"
 
+############
+############
++ Test DHCP6 Messages - DHCP6_AddrRegInform
+
+= DHCP6_AddrRegInform - Basic Instantiation
+raw(DHCP6_AddrRegInform()) == b'\x24\x00\x00\x00'
+
+= DHCP6_AddrRegInform - Basic Dissection
+a = DHCP6_AddrRegInform(b'\x24\x00\x00\x00')
+a.msgtype == 36 and a.trid == 0
+
+= DHCP6_AddrRegInform - Basic test of DHCP6_addrreginform.hashret()
+DHCP6_AddrRegInform().hashret() == b'\x00\x00\x00'
+
+= DHCP6_AddrRegInform - Test of DHCP6_addrreginform.hashret() with specific values
+DHCP6_AddrRegInform(trid=0xbbccdd).hashret() == b'\xbb\xcc\xdd'
+
+= DHCP6_AddrRegInform - UDP ports overload
+a=UDP()/DHCP6_AddrRegInform()
+a.sport == 546 and a.dport == 547
+
+= DHCP6_AddrRegInform - Dispatch based on UDP port
+a=UDP(raw(UDP()/DHCP6_AddrRegInform()))
+isinstance(a.payload, DHCP6_AddrRegInform)
+
+############
+############
++ Test DHCP6 Messages - DHCP6_AddrRegReply
+
+= DHCP6_AddrRegReply - Basic Instantiation
+raw(DHCP6_AddrRegReply()) == b'\x25\x00\x00\x00'
+
+= DHCP6_AddrRegReply - Basic Dissection
+a = DHCP6_AddrRegReply(b'\x25\x00\x00\x00')
+a.msgtype == 37 and a.trid == 0
+
+= DHCP6_AddrRegReply - Basic test of DHCP6_addrregreply.hashret()
+DHCP6_AddrRegReply().hashret() == b'\x00\x00\x00'
+
+= DHCP6_AddrRegReply - Test of DHCP6_addrregreply.hashret() with specific values
+DHCP6_AddrRegReply(trid=0xbbccdd).hashret() == b'\xbb\xcc\xdd'
+
+= DHCP6_AddrRegReply - UDP ports overload
+a=UDP()/DHCP6_AddrRegReply()
+a.sport == 546 and a.dport == 547
 
+= DHCP6_AddrRegReply - Dispatch based on UDP port
+a=UDP(raw(UDP()/DHCP6_AddrRegReply()))
+isinstance(a.payload, DHCP6_AddrRegReply)