add the pfcp client

pfcp_request_1_pdu_session1.py

+import time
+import uuid
+from datetime import datetime
+from threading import Thread, Event
+import scapy.sendrecv
+from scapy.contrib.gtp import GTP_U_Header, GTPPDUSessionContainer
+from scapy.contrib.pfcp import IE_ApplyAction, IE_CreateFAR, IE_CreatePDR, IE_DestinationInterface, \
+    IE_FAR_Id, \
+    IE_ForwardingParameters, IE_FSEID, IE_NetworkInstance, IE_NodeId, IE_PDI, IE_PDR_Id, IE_Precedence, \
+    IE_RecoveryTimeStamp, IE_SourceInterface, IE_UE_IP_Address, IE_FTEID, IE_OuterHeaderCreation, \
+    IE_OuterHeaderRemoval, \
+    PFCP, \
+    PFCPAssociationSetupRequest, PFCPSessionEstablishmentRequest, \
+    PFCPSessionModificationRequest, \
+    IE_CPFunctionFeatures, PFCPSessionEstablishmentResponse, IE_CreatedPDR, IE_QFI, PFCPHeartbeatResponse, \
+    IE_SequenceNumber, PFCPHeartbeatRequest
+from scapy.layers.inet import IP, UDP
+
+from scapy.all import sniff
+
+SMF_IP ="192.168.199.68" 
+UPF_IP_N3 = "192.168.10.10" 
+UPF_IP_N4 = "192.168.199.67"
+UPF_IP_N6 = "192.168.20.10" 
+UE_IP = "12.1.1.2"
+gNB_IP = "192.168.10.100"
+GOOGLE_DNS_IP = "8.8.8.8" 
+
+SEQ = 16770408
+
+FTEID_UL = 0x00000001
+FTEID_DL = 0x00000002
+
+def seid():
+    #return uuid.uuid4().int & (1 << 64) - 1
+    return 1
+
+
+def ie_fteid_set(fteid, ipv4):
+    return IE_FTEID(V4=1, TEID=fteid, ipv4=ipv4)
+
+
+def ie_fteid():
+    return IE_FTEID(CH=1, V4=1)
+
+
+def ie_fteid_ch(chid):
+    return IE_FTEID(CH=1, CHID=1, choose_id=chid, V4=1)
+
+
+def outer_header_creation(fteid, ipv4):
+    return IE_OuterHeaderCreation(
+        GTPUUDPIPV4=1, TEID=fteid, ipv4=ipv4)
+
+
+def create_pdr_ul(pdr_id, far_id, nwi, sdf_filter, source_iface, ip, sd):
+    return IE_CreatePDR(IE_list=[
+        IE_PDR_Id(id=pdr_id),
+        IE_Precedence(precedence=0),
+        IE_PDI(IE_list=[
+            IE_SourceInterface(interface=source_iface),
+            ie_fteid_ch(42),
+            IE_NetworkInstance(instance=nwi),
+            IE_UE_IP_Address(ipv4=ip, V4=1, SD=sd),
+            # IE_SDF_Filter(FD=1,
+            #              flow_description=sdf_filter),
+            IE_QFI(QFI=8)
+        ]),
+        IE_OuterHeaderRemoval(header="GTP-U/UDP/IPv4"),
+        IE_FAR_Id(id=far_id),
+    ])
+
+
+def create_pdr_dl(pdr_id, far_id, nwi, sdf_filter, source_iface, ip, sd):
+    return IE_CreatePDR(IE_list=[
+        IE_PDR_Id(id=pdr_id),
+        IE_Precedence(precedence=0),
+        IE_PDI(IE_list=[
+            IE_SourceInterface(interface=source_iface),
+            IE_NetworkInstance(instance=nwi),
+            # IE_SDF_Filter(FD=1, flow_description=sdf_filter),
+            IE_UE_IP_Address(ipv4=ip, V4=1, SD=sd)
+        ]),
+        IE_FAR_Id(id=far_id)
+    ])
+
+
+def create_far_ul(far_id, nwi):
+    return IE_CreateFAR(IE_list=[
+        IE_FAR_Id(id=far_id),
+        IE_ApplyAction(FORW=1),
+        IE_ForwardingParameters(IE_list=[
+            # IE_DestinationInterface(interface="SGi-LAN/N6-LAN"),
+            IE_DestinationInterface(interface="Core"),
+            IE_NetworkInstance(instance=nwi),
+        ])
+    ])
+
+
+def create_far_dl(far_id, nwi, fteid, ipv4):
+    return IE_CreateFAR(IE_list=[
+        IE_FAR_Id(id=far_id),
+        IE_ApplyAction(FORW=1),
+        IE_ForwardingParameters(IE_list=[
+            IE_DestinationInterface(interface="Access"),
+            IE_NetworkInstance(instance=nwi),
+            outer_header_creation(fteid, ipv4)
+        ])
+    ])
+
+
+def session_establishment_ul(seid_):
+    return PFCPSessionEstablishmentRequest(IE_list=[
+        #IE_NodeId(id_type="FQDN", id=SMF_ID),
+        IE_FSEID(seid=seid_, ipv4= SMF_IP, v4=1),
+        create_pdr_ul(1, 1, "oai", "permit out ip from any to assigned", "Access", UE_IP, 0),
+        create_far_ul(1, "oai")
+    ])
+
+
+def session_modification_dl(seid_):
+    return PFCPSessionModificationRequest(IE_list=[
+        # IE_NodeId(id_type="FQDN", id=SMF_ID),
+        IE_FSEID(seid=seid_, ipv4= SMF_IP, v4=1),
+        create_pdr_dl(2, 2, "oai", "permit out ip from any to assigned", "Core", UE_IP, 1),
+        create_far_dl(2, "oai", FTEID_DL, gNB_IP),
+    ])
+
+
+# def icmp_request_ul(fteid, dst ="8.8.8.8"):
+#     res = scapy.sendrecv.sr1(IP(src=f"{gNB_IP}", dst="192.168.101.2", flags=["DF"]) /
+#                              UDP(sport=2152, dport=2152) / GTP_U_Header(teid=fteid) / GTPPDUSessionContainer(type=1,
+#                                                                                                              QFI=8) /
+#                              IP(src=f"{UE_IP}", dst=dst, flags=["DF"]) / ICMP()/(b"1"*48)
+#                              )
+#     print(res)
+
+
+def association():
+    ts = int((datetime.now() - datetime(1900, 1, 1)).total_seconds())
+    return (PFCPAssociationSetupRequest(IE_list=[
+        IE_NodeId(id_type="FQDN", id=SMF_IP),
+        IE_RecoveryTimeStamp(timestamp=ts),
+        IE_CPFunctionFeatures(OVRL=1, LOAD=1)
+    ]))
+
+
+def send_receive_pfcp(msg, seid_=None, recv=True, seq=None):
+    global SEQ
+    seq = seq if seq else SEQ
+
+    pfcp = PFCP(version=1, seq=seq,
+                S=0 if seid_ is None else 1,
+                seid=0 if seid_ is None else seid_)
+
+    SEQ += 1
+    pkt = IP(src=SMF_IP, dst=UPF_IP_N4, proto=17) / UDP(sport=8805, dport=8805) / pfcp / msg
+    # sr1 only returns first answered packet
+    if recv:
+        res = scapy.sendrecv.sr1(pkt)
+        print(res)
+        return res
+    else:
+        scapy.sendrecv.send(pkt)
+
+
+class Sniffer(Thread):
+    def __init__(self, if_name, filter, heartbeat=True):
+        super().__init__()
+        self.if_name = if_name
+        self.filter = filter
+        self.heartbeat = heartbeat
+        self.stop = Event()
+
+    def run(self):
+        sniff(iface=self.if_name, filter=self.filter, prn=self.callback, store=0, stop_filter=self.should_stop)
+
+    def join(self, timeout=None):
+        self.stop.set()
+        super().join(timeout)
+
+    def callback(self, pkt):
+        print(f"Received packet: {pkt}")
+        try:
+            callback_resp = pkt[PFCPHeartbeatRequest]
+            seq_number = callback_resp[IE_SequenceNumber].number
+            send_receive_pfcp(PFCPHeartbeatResponse, recv=False, seq=seq_number)
+        except IndexError: # also traces other responses
+            pass
+
+
+    def should_stop(self, packet):
+        return self.stop.is_set()
+
+def main():
+    #heartbeat_sniffer = Sniffer(if_name="demo-oai", filter="dst host 192.168.100.2 and udp port 8805")
+    #icmp_sniffer = Sniffer(if_name="cn5g-access", filter="dst host 192.168.72.1 and icmp")
+
+    # print("Starting heartbeat and ICMP sniffer in background")
+    #heartbeat_sniffer.start()
+    #icmp_sniffer.start()
+
+    print("Send PFCP association setup")
+    send_receive_pfcp(association())
+    s = seid()
+    print("Now sleep for 10 seconds while we answer heartbeats")
+    time.sleep(1)
+    print("Send PFCP session establishment")
+    res = send_receive_pfcp(session_establishment_ul(s), seid_=0)
+    session_resp = res[PFCPSessionEstablishmentResponse]
+    created_fteid = session_resp[IE_CreatedPDR][IE_FTEID].TEID
+    print(f"Created FTEID: {hex(created_fteid)}")
+    time.sleep(1)
+
+    print("Send PFCP session modification")
+    send_receive_pfcp(session_modification_dl(s), seid_=s)
+
+    time.sleep(1)
+
+    # TODO this hangs currently, because scapy does not find the return value. I really would like to verify here
+    # if there is a response
+    #icmp_request_ul(created_fteid, "192.168.73.135")
+    # icmp_request_ul(created_fteid, "8.8.8.8")
+
+    time.sleep(1)
+
+if __name__ == "__main__":
+    main()
+