APCO, PrivateExtension & ULI-Timestamp IE (#2761)

* APCO IE; PrivateExtension IE

* Add tests for APCO

* Add ULI TImestamp

* Fix flake8 error

* fix flake8 error-2

* Change extension and timestamp to lowercase

* Update gtp_v2.uts

* Fix apco test

Author: UmakantKulkarni

scapy/contrib/gtp_v2.py

@@ -240,6 +240,8 @@
              136: "FQDN",
              145: "UCI",
              161: "Max MBR/APN-AMBR (MMBR)",
+             163: "Additional Protocol Configuration Options",
+             170: "ULI Timestamp",
              172: "RAN/NAS Cause",
              197: "Extended Protocol Configuration Options",
              202: "UP Function Selection Indication Flags",
@@ -444,6 +446,16 @@ class IE_ULI(gtp.IE_Base):
     ]
 
 
+class IE_ULI_Timestamp(gtp.IE_Base):
+    name = "IE ULI Timestamp"
+    fields_desc = [
+        ByteEnumField("ietype", 170, IEType),
+        ShortField("length", None),
+        BitField("CR_flag", 0, 4),
+        BitField("instance", 0, 4),
+        XIntField("timestamp", 0)]
+
+
 # 3GPP TS 29.274 v12.12.0 section 8.22
 INTERFACE_TYPES = {
     0: "S1-U eNodeB GTP-U interface",
@@ -1291,6 +1303,19 @@ class IE_EPCO(gtp.IE_Base):
                                    length_from=lambda pkt: pkt.length - 1)]
 
 
+class IE_APCO(gtp.IE_Base):
+    name = "IE Additional Protocol Configuration Options"
+    fields_desc = [ByteEnumField("ietype", 163, IEType),
+                   ShortField("length", None),
+                   BitField("CR_flag", 0, 4),
+                   BitField("instance", 0, 4),
+                   BitField("extension", 0, 1),
+                   BitField("SPARE", 0, 4),
+                   BitField("PPP", 0, 3),
+                   PacketListField("Protocols", None, PCO_protocol_dispatcher,
+                                   length_from=lambda pkt: pkt.length - 1)]
+
+
 class IE_PAA(gtp.IE_Base):
     name = "IE PAA"
     fields_desc = [ByteEnumField("ietype", 79, IEType),
@@ -1454,10 +1479,8 @@ class IE_PrivateExtension(gtp.IE_Base):
         BitField("SPARE", 0, 4),
         BitField("instance", 0, 4),
         ShortEnumField("enterprisenum", None, IANA_ENTERPRISE_NUMBERS),
-    ]
-
-    def extract_padding(self, s):
-        return s[:self.length], ''
+        StrLenField("proprietaryvalue", "",
+                    length_from=lambda x: x.length - 2)]
 
 
 ietypecls = {1: IE_IMSI,
@@ -1493,6 +1516,8 @@ def extract_padding(self, s):
              136: IE_FQDN,
              145: IE_UCI,
              161: IE_MMBR,
+             163: IE_APCO,
+             170: IE_ULI_Timestamp,
              172: IE_Ran_Nas_Cause,
              197: IE_EPCO,
              202: IE_UPF_SelInd_Flags,

test/contrib/gtp_v2.uts

@@ -175,6 +175,16 @@ ie.Protocols[0].type == 27
 ie = IE_EPCO(Protocols=[PCO_S_Nssai(type=27, length=0)], ietype=197, length=4, CR_flag=0, instance=0, Extension=1, SPARE=0, PPP=0)
 ie.Extension == 1 and ie.ietype == 197 and ie.Protocols[0].type == 27 and ie.Protocols[0].length == 0
 
+= IE_APCO, dissection
+h = "d89ef3da40e2fa163e956dce0800450000360001000040115d650a0f0f3d01020304084b084b00220000482000160000000100000100a3000a0080000c00001200000d00"
+gtp = Ether(hex_bytes(h))
+ie = gtp.IE_list[0]
+ie.Protocols[0].type == 12 and ie.Protocols[1].type == 18 and ie.Protocols[2].type == 13
+
+= IE_APCO, basic instantiation
+ie = IE_APCO(Protocols=[PCO_P_CSCF_IPv4_Address_Request(address=None, type=12, length=0),PCO_P_CSCF_Re_selection_Support(type=18, length=0),PCO_DNS_Server_IPv4(address=None, type=13, length=0)], ietype=163, length=10, CR_flag=0, instance=0, extension=1, SPARE=0, PPP=0)
+ie.extension == 1 and ie.ietype == 163 and ie.length == 10 and ie.Protocols[0].type == 12 and ie.Protocols[1].type == 18 and ie.Protocols[2].type == 13
+
 = IE_MMContext_EPS, dissection
 h = "d89ef3da40e2fa163e956dce08004500007f0001000040114bbd0a0a0f3d0a0f0b5b084b084b006b5a234883005f0000180f76d163006b0046008800910000020000021890aa80be385102083701a2907066f8bd9f2a28b717671c71c71c71c71c71c70100003d090002625a00028040000812345678900000000000000000006d000900880005000470677731"
 gtp = Ether(hex_bytes(h))
@@ -440,10 +450,16 @@ gtp = Ether(hex_bytes(h))
 isinstance(gtp.IE_list[0], IE_NotImplementedTLV)
 isinstance(gtp.IE_list[0].payload, NoPayload)
 
-= IE_PrivateExtension
-h = "5001003500303900ff0031002b79deadbeef1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef12345678"
-gtp = GTPHeader(hex_bytes(h))
-gtp.show2()
-(ie,) = gtp.IE_list
-ie.enterprisenum == 11129
-bytes_hex(ie.payload) == b"deadbeef1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef12345678"
+= IE_PrivateExtension, dissection
+h = "d89ef3da40e2fa163e956dce08004500005b0001000040115d400a0f0f3d01020304084b084b00470000482000620000000100000100ff0015000137020046462d46462d46462d46462d46462d4646ff00160001370100000100000000000000000000000000000000"
+gtp = Ether(hex_bytes(h))
+ie1 = gtp.IE_list[0]
+ie2 = gtp.IE_list[1]
+ie1.enterprisenum == 311 and bytes_hex(ie1.proprietaryvalue) == b'020046462d46462d46462d46462d46462d4646'
+ie2.enterprisenum == 311 and bytes_hex(ie2.proprietaryvalue) == b'0100000100000000000000000000000000000000'
+
+= IE_PrivateExtension, basic instantiation
+ie1 = IE_PrivateExtension(ietype=255, length=21, SPARE=0, instance=0, enterprisenum=311, proprietaryvalue=hex_bytes('020046462d46462d46462d46462d46462d4646'))
+ie2 = IE_PrivateExtension(ietype=255, length=22, SPARE=0, instance=0, enterprisenum=311, proprietaryvalue=hex_bytes('0100000100000000000000000000000000000000'))
+ie1.enterprisenum == 311 and bytes_hex(ie1.proprietaryvalue) == b'020046462d46462d46462d46462d46462d4646'
+ie2.enterprisenum == 311 and bytes_hex(ie2.proprietaryvalue) == b'0100000100000000000000000000000000000000'