srv6-mobile: Support GTP4/6.DT and User Plane message mapping

Support the following new features in srv6-mobile.

1. GTP4.DT
2. GTP6.DT
3. User Plane Message encoding based on draft-murakami-dmm-user-plane-message-encoding-01
4. Add SRv6 mobile test cases

Type: feature

Signed-off-by: Tetsuya Murakami <tetsuya.mrk@gmail.com>
Change-Id: I890e5171bf03513d54b4830f01b9dc7f47fe7c48
Signed-off-by: Tetsuya Murakami <tetsuya.mrk@gmail.com>

10 files changed, 2119 insertions, 206 deletions

diff --git a/src/plugins/srv6-mobile/CMakeLists.txt b/src/plugins/srv6-mobile/CMakeLists.txt
index ebd03f7fbf4..5a9945c2e4f 100644
--- a/src/plugins/srv6-mobile/CMakeLists.txt
+++ b/src/plugins/srv6-mobile/CMakeLists.txt
@@ -15,9 +15,11 @@ add_vpp_plugin(srv6mobile
   SOURCES
   gtp4_e.c
   gtp4_d.c
+  gtp4_dt.c
   gtp6_e.c
   gtp6_d.c
   gtp6_d_di.c
+  gtp6_dt.c
   node.c
 
   INSTALL_HEADERS
diff --git a/src/plugins/srv6-mobile/extra/Dockerfile.j2.release b/src/plugins/srv6-mobile/extra/Dockerfile.j2.release
index 851aef66197..bdb57a61511 100644
--- a/src/plugins/srv6-mobile/extra/Dockerfile.j2.release
+++ b/src/plugins/srv6-mobile/extra/Dockerfile.j2.release
@@ -16,6 +16,7 @@ RUN set -eux; \
     iproute2 \
     tcpdump \
     python3-cffi \
+    python2.7 \
     netcat; \
     rm -rf /var/lib/apt/lists/*; \
     mv /usr/sbin/tcpdump /usr/bin/tcpdump
diff --git a/src/plugins/srv6-mobile/extra/runner.py b/src/plugins/srv6-mobile/extra/runner.py
index 79ec2d007c5..c438fb161b7 100755
--- a/src/plugins/srv6-mobile/extra/runner.py
+++ b/src/plugins/srv6-mobile/extra/runner.py
@@ -135,7 +135,7 @@ class Container(object):
         self.vppctl_exec("set int mac address pg0 {}".format(local_mac))
         self.vppctl_exec("set int ip addr pg0 {}".format(local_ip))
         self.vppctl_exec(
-            "set ip6 neighbor pg0 {} {}".format(remote_ip, remote_mac))
+            "set ip neighbor pg0 {} {}".format(remote_ip, remote_mac))
         self.vppctl_exec("set int state pg0 up")
 
     def pg_create_interface4(self, local_ip, remote_ip, local_mac, remote_mac):
@@ -145,7 +145,7 @@ class Container(object):
         self.vppctl_exec("create packet-generator interface pg0")
         self.vppctl_exec("set int mac address pg0 {}".format(local_mac))
         self.vppctl_exec("set int ip addr pg0 {}".format(local_ip))
-        self.vppctl_exec("set ip arp pg0 {} {}".format(remote_ip, remote_mac))
+        self.vppctl_exec("set ip neighbor pg0 {} {}".format(remote_ip, remote_mac))
         self.vppctl_exec("set int state pg0 up")
 
     def pg_create_interface6(self, local_ip, remote_ip, local_mac, remote_mac):
@@ -154,10 +154,30 @@ class Container(object):
         time.sleep(2)
         self.vppctl_exec("create packet-generator interface pg0")
         self.vppctl_exec("set int mac address pg0 {}".format(local_mac))
-        self.vppctl_exec("set int ip6 addr pg0 {}".format(local_ip))
-        self.vppctl_exec("set ip6 arp pg0 {} {}".format(remote_ip, remote_mac))
+        self.vppctl_exec("set int ip addr pg0 {}".format(local_ip))
+        self.vppctl_exec("set ip neighbor pg0 {} {}".format(remote_ip, remote_mac))
         self.vppctl_exec("set int state pg0 up")
 
+    def pg_create_interface4_name(self, ifname, local_ip, remote_ip, local_mac, remote_mac):
+        # remote_ip can't have subnet mask
+
+        time.sleep(2)
+        self.vppctl_exec("create packet-generator interface {}".format(ifname))
+        self.vppctl_exec("set int mac address {} {}".format(ifname, local_mac))
+        self.vppctl_exec("set int ip addr {} {}".format(ifname, local_ip))
+        self.vppctl_exec("set ip neighbor {} {} {}".format(ifname, remote_ip, remote_mac))
+        self.vppctl_exec("set int state {} up".format(ifname))
+
+    def pg_create_interface6_name(self, ifname, local_ip, remote_ip, local_mac, remote_mac):
+        # remote_ip can't have subnet mask
+
+        time.sleep(2)
+        self.vppctl_exec("create packet-generator interface {}".format(ifname))
+        self.vppctl_exec("set int mac address {} {}".format(ifname, local_mac))
+        self.vppctl_exec("set int ip addr {} {}".format(ifname, local_ip))
+        self.vppctl_exec("set ip neighbor {} {} {}".format(ifname, remote_ip, remote_mac))
+        self.vppctl_exec("set int state {} up".format(ifname))
+
     def pg_enable(self):
         # start packet generator
         self.vppctl_exec("packet-generator enable")
@@ -176,6 +196,13 @@ class Container(object):
             "packet-generator capture pg0 pcap {}".format(
                 self.pg_output_file_in))
 
+    def pg_start_capture_name(self, ifname):
+        if exists(self.pg_output_file):
+            remove(self.pg_output_file)
+        self.vppctl_exec(
+            "packet-generator capture {} pcap {}".format(
+                ifname, self.pg_output_file_in))
+
     def pg_read_packets(self):
         return rdpcap(self.pg_output_file)
 
@@ -184,6 +211,11 @@ class Container(object):
             "ip route add {} via host-{} {}".format(
                 subnet, out_if_name, next_hop_ip))
 
+    def set_ipv6_route2(self, out_if_name, next_hop_ip, subnet):
+        self.vppctl_exec(
+            "ip route add {} via {} {}".format(
+                subnet, out_if_name, next_hop_ip))
+
     def set_ip_pgroute(self, out_if_name, next_hop_ip, subnet):
         self.vppctl_exec("ip route add {} via {} {}".format(
             subnet, out_if_name, next_hop_ip))
@@ -1089,6 +1121,142 @@ class Program(object):
         for p in c4.pg_read_packets():
             p.show2()
 
+    def test_gtp4_reply(self):
+        # TESTS:
+        # trace add af-packet-input 10
+        # pg interface on c1 172.20.0.1
+        # pg interface on c4 B::1/120
+
+        self.start_containers()
+
+        c1 = self.containers.get(self.get_name(self.instance_names[0]))
+        c2 = self.containers.get(self.get_name(self.instance_names[1]))
+        c3 = self.containers.get(self.get_name(self.instance_names[2]))
+        c4 = self.containers.get(self.get_name(self.instance_names[-1]))
+
+        c1.pg_create_interface4(
+            local_ip="172.16.0.1/30",
+            remote_ip="172.16.0.2/30",
+            local_mac="aa:bb:cc:dd:ee:01",
+            remote_mac="aa:bb:cc:dd:ee:02")
+        c4.pg_create_interface4(
+            local_ip="1.0.0.2/30",
+            remote_ip="1.0.0.1",
+            local_mac="aa:bb:cc:dd:ee:11",
+            remote_mac="aa:bb:cc:dd:ee:22")
+
+        c1.vppctl_exec("set sr encaps source addr A1::1")
+        c1.vppctl_exec("sr policy add bsid D4:: next D2:: next D3::")
+        c1.vppctl_exec("sr policy add bsid D5:: behavior t.m.gtp4.d D4::/32 v6src_prefix C1::/64 nhtype ipv4")
+        c1.vppctl_exec("sr steer l3 172.20.0.1/32 via bsid D5::")
+
+        c2.vppctl_exec("sr localsid address D2:: behavior end")
+
+        c3.vppctl_exec("sr localsid address D3:: behavior end")
+
+        c4.vppctl_exec(
+            "sr localsid prefix D4::/32 "
+            "behavior end.m.gtp4.e v4src_position 64")
+
+        c2.set_ipv6_route("eth2", "A2::2", "D3::/128")
+        c2.set_ipv6_route("eth1", "A1::1", "C::/120")
+        c3.set_ipv6_route("eth2", "A3::2", "D4::/32")
+        c3.set_ipv6_route("eth1", "A2::1", "C::/120")
+        c4.set_ip_pgroute("pg0", "1.0.0.1", "172.20.0.1/32")
+
+        p = (Ether(src="aa:bb:cc:dd:ee:02", dst="aa:bb:cc:dd:ee:01") /
+             IP(src="172.20.0.2", dst="172.20.0.1") /
+             UDP(sport=2152, dport=2152) /
+             GTP_U_Header(gtp_type="echo_response", S=1, teid=200, seq=200))
+
+        print("Sending packet on {}:".format(c1.name))
+        p.show2()
+
+        c1.enable_trace(10)
+        c4.enable_trace(10)
+
+        c4.pg_start_capture()
+
+        c1.pg_create_stream(p)
+        c1.pg_enable()
+
+        # timeout (sleep) if needed
+        print("Sleeping")
+        time.sleep(5)
+
+        print("Receiving packet on {}:".format(c4.name))
+        for p in c4.pg_read_packets():
+            p.show2()
+
+    def test_gtp4_error(self):
+        # TESTS:
+        # trace add af-packet-input 10
+        # pg interface on c1 172.20.0.1
+        # pg interface on c4 B::1/120
+
+        self.start_containers()
+
+        c1 = self.containers.get(self.get_name(self.instance_names[0]))
+        c2 = self.containers.get(self.get_name(self.instance_names[1]))
+        c3 = self.containers.get(self.get_name(self.instance_names[2]))
+        c4 = self.containers.get(self.get_name(self.instance_names[-1]))
+
+        c1.pg_create_interface4(
+            local_ip="172.16.0.1/30",
+            remote_ip="172.16.0.2/30",
+            local_mac="aa:bb:cc:dd:ee:01",
+            remote_mac="aa:bb:cc:dd:ee:02")
+        c4.pg_create_interface4(
+            local_ip="1.0.0.2/30",
+            remote_ip="1.0.0.1",
+            local_mac="aa:bb:cc:dd:ee:11",
+            remote_mac="aa:bb:cc:dd:ee:22")
+
+        c1.vppctl_exec("set sr encaps source addr A1::1")
+        c1.vppctl_exec("sr policy add bsid D4:: next D2:: next D3::")
+        c1.vppctl_exec("sr policy add bsid D5:: behavior t.m.gtp4.d D4::/32 v6src_prefix C1::/64 nhtype ipv4")
+        c1.vppctl_exec("sr steer l3 172.20.0.1/32 via bsid D5::")
+
+        c2.vppctl_exec("sr localsid address D2:: behavior end")
+
+        c3.vppctl_exec("sr localsid address D3:: behavior end")
+
+        c4.vppctl_exec(
+            "sr localsid prefix D4::/32 "
+            "behavior end.m.gtp4.e v4src_position 64")
+
+        c2.set_ipv6_route("eth2", "A2::2", "D3::/128")
+        c2.set_ipv6_route("eth1", "A1::1", "C::/120")
+        c3.set_ipv6_route("eth2", "A3::2", "D4::/32")
+        c3.set_ipv6_route("eth1", "A2::1", "C::/120")
+        c4.set_ip_pgroute("pg0", "1.0.0.1", "172.20.0.1/32")
+
+        p = (Ether(src="aa:bb:cc:dd:ee:02", dst="aa:bb:cc:dd:ee:01") /
+             IP(src="172.20.0.2", dst="172.20.0.1") /
+             UDP(sport=2152, dport=2152) /
+             GTP_U_Header(gtp_type="error_indication", S=1, teid=200, seq=200)/
+             IE_TEIDI(TEIDI=65535)/IE_GSNAddress(address="1.1.1.1")/
+             IE_PrivateExtension(extention_value="z"))
+
+        print("Sending packet on {}:".format(c1.name))
+        p.show2()
+
+        c1.enable_trace(10)
+        c4.enable_trace(10)
+
+        c4.pg_start_capture()
+
+        c1.pg_create_stream(p)
+        c1.pg_enable()
+
+        # timeout (sleep) if needed
+        print("Sleeping")
+        time.sleep(5)
+
+        print("Receiving packet on {}:".format(c4.name))
+        for p in c4.pg_read_packets():
+            p.show2()
+
     def test_gtp4_ipv6(self):
         # TESTS:
         # trace add af-packet-input 10
@@ -1452,6 +1620,154 @@ class Program(object):
         for p in c4.pg_read_packets():
             p.show2()
 
+    def test_gtp6_drop_in_reply(self):
+        # TESTS:
+        # trace add af-packet-input 10
+        # pg interface on c1 172.20.0.1
+        # pg interface on c4 B::1/120
+
+        self.start_containers()
+
+        print("Deleting the old containers...")
+        time.sleep(30)
+        print("Starting the new containers...")
+
+        c1 = self.containers.get(self.get_name(self.instance_names[0]))
+        c2 = self.containers.get(self.get_name(self.instance_names[1]))
+        c3 = self.containers.get(self.get_name(self.instance_names[2]))
+        c4 = self.containers.get(self.get_name(self.instance_names[-1]))
+
+        c1.pg_create_interface(
+            local_ip="C::1/120",
+            remote_ip="C::2",
+            local_mac="aa:bb:cc:dd:ee:01",
+            remote_mac="aa:bb:cc:dd:ee:02")
+        c4.pg_create_interface(
+            local_ip="B::1/120",
+            remote_ip="B::2",
+            local_mac="aa:bb:cc:dd:ee:11",
+            remote_mac="aa:bb:cc:dd:ee:22")
+
+        c1.vppctl_exec("set sr encaps source addr A1::1")
+        c1.vppctl_exec("sr policy add bsid D4:: next D2:: next D3::")
+
+        c1.vppctl_exec(
+            "sr localsid prefix D::/64 behavior end.m.gtp6.d.di D4::/64")
+
+        c2.vppctl_exec("sr localsid address D2:: behavior end")
+
+        c3.vppctl_exec("sr localsid address D3:: behavior end")
+
+        c4.vppctl_exec("sr localsid prefix D4::/64 behavior end.m.gtp6.e")
+
+        c2.set_ipv6_route("eth2", "A2::2", "D3::/128")
+        c2.set_ipv6_route("eth1", "A1::1", "C::/120")
+        c3.set_ipv6_route("eth2", "A3::2", "D4::/32")
+        c3.set_ipv6_route("eth1", "A2::1", "C::/120")
+        c4.set_ip_pgroute("pg0", "B::2", "D::2/128")
+
+        print("Waiting...")
+        time.sleep(30)
+
+        p = (Ether(src="aa:bb:cc:dd:ee:02", dst="aa:bb:cc:dd:ee:01") /
+             IPv6(src="C::2", dst="D::2") /
+             UDP(sport=2152, dport=2152) /
+             GTP_U_Header(gtp_type="echo_response", S=1, teid=200, seq=300))
+
+        print("Sending packet on {}:".format(c1.name))
+        p.show2()
+
+        c1.enable_trace(10)
+        c4.enable_trace(10)
+
+        c4.pg_start_capture()
+
+        c1.pg_create_stream(p)
+        c1.pg_enable()
+
+        # timeout (sleep) if needed
+        print("Sleeping")
+        time.sleep(5)
+
+        print("Receiving packet on {}:".format(c4.name))
+        for p in c4.pg_read_packets():
+            p.show2()
+
+    def test_gtp6_drop_in_error(self):
+        # TESTS:
+        # trace add af-packet-input 10
+        # pg interface on c1 172.20.0.1
+        # pg interface on c4 B::1/120
+
+        self.start_containers()
+
+        print("Deleting the old containers...")
+        time.sleep(30)
+        print("Starting the new containers...")
+
+        c1 = self.containers.get(self.get_name(self.instance_names[0]))
+        c2 = self.containers.get(self.get_name(self.instance_names[1]))
+        c3 = self.containers.get(self.get_name(self.instance_names[2]))
+        c4 = self.containers.get(self.get_name(self.instance_names[-1]))
+
+        c1.pg_create_interface(
+            local_ip="C::1/120",
+            remote_ip="C::2",
+            local_mac="aa:bb:cc:dd:ee:01",
+            remote_mac="aa:bb:cc:dd:ee:02")
+        c4.pg_create_interface(
+            local_ip="B::1/120",
+            remote_ip="B::2",
+            local_mac="aa:bb:cc:dd:ee:11",
+            remote_mac="aa:bb:cc:dd:ee:22")
+
+        c1.vppctl_exec("set sr encaps source addr A1::1")
+        c1.vppctl_exec("sr policy add bsid D4:: next D2:: next D3::")
+
+        c1.vppctl_exec(
+            "sr localsid prefix D::/64 behavior end.m.gtp6.d.di D4::/64")
+
+        c2.vppctl_exec("sr localsid address D2:: behavior end")
+
+        c3.vppctl_exec("sr localsid address D3:: behavior end")
+
+        c4.vppctl_exec("sr localsid prefix D4::/64 behavior end.m.gtp6.e")
+
+        c2.set_ipv6_route("eth2", "A2::2", "D3::/128")
+        c2.set_ipv6_route("eth1", "A1::1", "C::/120")
+        c3.set_ipv6_route("eth2", "A3::2", "D4::/32")
+        c3.set_ipv6_route("eth1", "A2::1", "C::/120")
+        c4.set_ip_pgroute("pg0", "B::2", "D::2/128")
+
+        print("Waiting...")
+        time.sleep(30)
+
+        p = (Ether(src="aa:bb:cc:dd:ee:02", dst="aa:bb:cc:dd:ee:01") /
+             IPv6(src="C::2", dst="D::2") /
+             UDP(sport=2152, dport=2152) /
+             GTP_U_Header(gtp_type="error_indication", S=1, teid=200, seq=300)/
+             IE_TEIDI(TEIDI=65535)/IE_GSNAddress(address="1.1.1.1")/
+             IE_PrivateExtension(extention_value="z"))
+
+        print("Sending packet on {}:".format(c1.name))
+        p.show2()
+
+        c1.enable_trace(10)
+        c4.enable_trace(10)
+
+        c4.pg_start_capture()
+
+        c1.pg_create_stream(p)
+        c1.pg_enable()
+
+        # timeout (sleep) if needed
+        print("Sleeping")
+        time.sleep(5)
+
+        print("Receiving packet on {}:".format(c4.name))
+        for p in c4.pg_read_packets():
+            p.show2()
+
     def test_gtp6_drop_in_ipv6(self):
         # TESTS:
         # trace add af-packet-input 10
@@ -1641,6 +1957,7 @@ class Program(object):
 
         c3.vppctl_exec("sr localsid address D3:: behavior end")
 
+        c4.vppctl_exec("set ip neighbor pg0 1.0.0.1 aa:bb:cc:dd:ee:22")
         c4.vppctl_exec("sr localsid prefix D4::/64 behavior end.dt4 2")
 
         c2.set_ipv6_route("eth2", "A2::2", "D3::/128")
@@ -1716,6 +2033,7 @@ class Program(object):
 
         c3.vppctl_exec("sr localsid address D3:: behavior end")
 
+        c4.vppctl_exec("set ip neighbor pg0 1.0.0.1 aa:bb:cc:dd:ee:22")
         c4.vppctl_exec("sr localsid prefix D4::/64 behavior end.dt4 2")
 
         c2.set_ipv6_route("eth2", "A2::2", "D3::/128")
@@ -1792,6 +2110,7 @@ class Program(object):
 
         c3.vppctl_exec("sr localsid address D3:: behavior end")
 
+        c4.vppctl_exec("set ip neighbor pg0 B::2 aa:bb:cc:dd:ee:22")
         c4.vppctl_exec("sr localsid prefix D4::/64 behavior end.dt6 2")
 
         c2.set_ipv6_route("eth2", "A2::2", "D3::/128")
@@ -1867,6 +2186,7 @@ class Program(object):
 
         c3.vppctl_exec("sr localsid address D3:: behavior end")
 
+        c4.vppctl_exec("set ip neighbor pg0 B::2 aa:bb:cc:dd:ee:22")
         c4.vppctl_exec("sr localsid prefix D4::/64 behavior end.dt6 2")
 
         c2.set_ipv6_route("eth2", "A2::2", "D3::/128")
@@ -1905,6 +2225,133 @@ class Program(object):
         for p in c4.pg_read_packets():
             p.show2()
 
+    def test_gtp6_dt(self):
+        # TESTS:
+        # trace add af-packet-input 10
+        # pg interface on c1 172.20.0.1
+        # pg interface on c4 B::1/120
+
+        self.start_containers()
+
+        print("Deleting the old containers...")
+        time.sleep(30)
+        print("Starting the new containers...")
+
+        c1 = self.containers.get(self.get_name(self.instance_names[0]))
+
+        c1.pg_create_interface6_name(
+            ifname="pg0",
+            local_ip="C::1/120",
+            remote_ip="C::2",
+            local_mac="aa:bb:cc:dd:ee:01",
+            remote_mac="aa:bb:cc:dd:ee:02")
+
+        c1.pg_create_interface4_name(
+            ifname="pg1",
+            local_ip="1.0.0.2/30",
+            remote_ip="1.0.0.1",
+            local_mac="aa:bb:cc:dd:ee:11",
+            remote_mac="aa:bb:cc:dd:ee:22")
+
+        c1.vppctl_exec("set sr encaps source addr A1::1")
+
+        c1.vppctl_exec(
+            "sr localsid prefix D::/64 behavior end.m.gtp6.dt46 fib-table 0 local-fib-table 0")
+
+        c1.vppctl_exec("set ip neighbor pg1 1.0.0.1 aa:bb:cc:dd:ee:22")
+        c1.set_ip_pgroute("pg1", "1.0.0.1", "172.200.0.1/32")
+
+        print("Waiting...")
+        time.sleep(30)
+
+        p = (Ether(src="aa:bb:cc:dd:ee:02", dst="aa:bb:cc:dd:ee:01") /
+             IPv6(src="C::2", dst="D::2") /
+             UDP(sport=2152, dport=2152) /
+             GTP_U_Header(gtp_type="g_pdu", teid=200) /
+             IP(src="172.100.0.1", dst="172.200.0.1") /
+             ICMP())
+
+        print("Sending packet on {}:".format(c1.name))
+        p.show2()
+
+        c1.enable_trace(10)
+
+        c1.pg_start_capture_name(ifname="pg1")
+
+        c1.pg_create_stream(p)
+        c1.pg_enable()
+
+        # timeout (sleep) if needed
+        print("Sleeping")
+        time.sleep(5)
+
+        print("Receiving packet on {}:".format(c1.name))
+        for p in c1.pg_read_packets():
+            p.show2()
+
+    def test_gtp4_dt(self):
+        # TESTS:
+        # trace add af-packet-input 10
+        # pg interface on c1 172.20.0.1
+        # pg interface on c4 B::1/120
+
+        self.start_containers()
+
+        print("Deleting the old containers...")
+        time.sleep(30)
+        print("Starting the new containers...")
+
+        c1 = self.containers.get(self.get_name(self.instance_names[0]))
+
+        c1.pg_create_interface4_name(
+            ifname="pg0",
+            local_ip="172.16.0.1/30",
+            remote_ip="172.16.0.2",
+            local_mac="aa:bb:cc:dd:ee:01",
+            remote_mac="aa:bb:cc:dd:ee:02")
+
+        c1.pg_create_interface4_name(
+            ifname="pg1",
+            local_ip="1.0.0.2/30",
+            remote_ip="1.0.0.1",
+            local_mac="aa:bb:cc:dd:ee:11",
+            remote_mac="aa:bb:cc:dd:ee:22")
+
+        c1.vppctl_exec("set sr encaps source addr A1::1")
+        c1.vppctl_exec("sr policy add bsid D5:: behavior t.m.gtp4.dt4 fib-table 0")
+        c1.vppctl_exec("sr steer l3 172.20.0.1/32 via bsid D5::")
+
+        c1.vppctl_exec("set ip neighbor pg1 1.0.0.1 aa:bb:cc:dd:ee:22")
+        c1.set_ip_pgroute("pg1", "1.0.0.1", "172.200.0.1/32")
+
+        print("Waiting...")
+        time.sleep(30)
+
+        p = (Ether(src="aa:bb:cc:dd:ee:02", dst="aa:bb:cc:dd:ee:01") /
+             IP(src="172.20.0.2", dst="172.20.0.1") /
+             UDP(sport=2152, dport=2152) /
+             GTP_U_Header(gtp_type="g_pdu", teid=200) /
+             IP(src="172.100.0.1", dst="172.200.0.1") /
+             ICMP())
+
+        print("Sending packet on {}:".format(c1.name))
+        p.show2()
+
+        c1.enable_trace(10)
+
+        c1.pg_start_capture_name(ifname="pg1")
+
+        c1.pg_create_stream(p)
+        c1.pg_enable()
+
+        # timeout (sleep) if needed
+        print("Sleeping")
+        time.sleep(5)
+
+        print("Receiving packet on {}:".format(c1.name))
+        for p in c1.pg_read_packets():
+            p.show2()
+
     def status_containers(self):
 
         print("Instances:")
@@ -2008,17 +2455,23 @@ def get_args():
             "gtp4_usid",
             "gtp4_5g",
             "gtp4_echo",
+            "gtp4_reply",
+            "gtp4_error",
             "gtp4_ipv6",
             "gtp4_ipv6_5g",
             "gtp6_drop_in",
             "gtp6_drop_in_5g",
             "gtp6_drop_in_echo",
+            "gtp6_drop_in_reply",
+            "gtp6_drop_in_error",
             "gtp6_drop_in_ipv6",
             "gtp6_drop_in_ipv6_5g",
             "gtp6",
             "gtp6_5g",
             "gtp6_ipv6",
-            "gtp6_ipv6_5g"])
+            "gtp6_ipv6_5g",
+            "gtp6_dt",
+            "gtp4_dt"])
 
     args = parser.parse_args()
     if not hasattr(args, "op") or not args.op:
@@ -2038,7 +2491,7 @@ def main(op=None, prefix=None, verbose=None,
         image = "srv6m-release-image"
     elif image == 'debug':
         image = "srv6m-image"
-    else
+    else:
         image = "srv6m-image"
 
     print("Target image: {}".format(image))
@@ -2080,6 +2533,10 @@ def main(op=None, prefix=None, verbose=None,
             program.test_gtp4_5g()
         elif op == 'gtp4_echo':
             program.test_gtp4_echo()
+        elif op == 'gtp4_reply':
+            program.test_gtp4_reply()
+        elif op == 'gtp4_error':
+            program.test_gtp4_error()
         elif op == 'gtp4_ipv6':
             program.test_gtp4_ipv6()
         elif op == 'gtp4_ipv6_5g':
@@ -2090,6 +2547,10 @@ def main(op=None, prefix=None, verbose=None,
             program.test_gtp6_drop_in_5g()
         elif op == 'gtp6_drop_in_echo':
             program.test_gtp6_drop_in_echo()
+        elif op == 'gtp6_drop_in_reply':
+            program.test_gtp6_drop_in_reply()
+        elif op == 'gtp6_drop_in_error':
+            program.test_gtp6_drop_in_error()
         elif op == 'gtp6_drop_in_ipv6':
             program.test_gtp6_drop_in_ipv6()
         elif op == 'gtp6_drop_in_ipv6_5g':
@@ -2102,6 +2563,10 @@ def main(op=None, prefix=None, verbose=None,
             program.test_gtp6_ipv6()
         elif op == 'gtp6_ipv6_5g':
             program.test_gtp6_ipv6_5g()
+        elif op == 'gtp6_dt':
+            program.test_gtp6_dt()
+        elif op == 'gtp4_dt':
+            program.test_gtp4_dt()
 
     except Exception:
         program.logger.exception("")
diff --git a/src/plugins/srv6-mobile/gtp4_dt.c b/src/plugins/srv6-mobile/gtp4_dt.c
new file mode 100644
index 00000000000..44a4af34c2f
--- /dev/null
+++ b/src/plugins/srv6-mobile/gtp4_dt.c
@@ -0,0 +1,205 @@
+/*
+ * srv6_t_m_gtp4_dt.c
+ *
+ * Copyright (c) 2019 Arrcus Inc and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <vnet/vnet.h>
+#include <vnet/adj/adj.h>
+#include <vnet/fib/fib_table.h>
+#include <vnet/plugin/plugin.h>
+#include <vpp/app/version.h>
+#include <srv6-mobile/mobile.h>
+
+srv6_t_main_v4_dt_t srv6_t_main_v4_dt;
+
+static void
+clb_dpo_lock_srv6_t_m_gtp4_dt (dpo_id_t * dpo)
+{
+}
+
+static void
+clb_dpo_unlock_srv6_t_m_gtp4_dt (dpo_id_t * dpo)
+{
+}
+
+static u8 *
+clb_dpo_format_srv6_t_m_gtp4_dt (u8 * s, va_list * args)
+{
+  index_t index = va_arg (*args, index_t);
+  CLIB_UNUSED (u32 indent) = va_arg (*args, u32);
+
+  return (format (s, "SR: dynamic_proxy_index:[%u]", index));
+}
+
+const static dpo_vft_t dpo_vft = {
+  .dv_lock = clb_dpo_lock_srv6_t_m_gtp4_dt,
+  .dv_unlock = clb_dpo_unlock_srv6_t_m_gtp4_dt,
+  .dv_format = clb_dpo_format_srv6_t_m_gtp4_dt,
+};
+
+const static char *const srv6_t_m_gtp4_dt_nodes[] = {
+  "srv6-t-m-gtp4-dt",
+  NULL,
+};
+
+const static char *const srv6_t_m_gtp4_dt_v6_nodes[] = {
+  "error-drop",
+  NULL,
+};
+
+const static char *const *const dpo_nodes[DPO_PROTO_NUM] = {
+  [DPO_PROTO_IP6] = srv6_t_m_gtp4_dt_v6_nodes,
+  [DPO_PROTO_IP4] = srv6_t_m_gtp4_dt_nodes,
+};
+
+static u8 fn_name[] = "SRv6-T.M.GTP4.DT-plugin";
+static u8 keyword_str[] = "t.m.gtp4.dt";
+static u8 def_str[] = "Transit function with DT for IPv4/GTP tunnel";
+static u8 param_str[] = "fib-index <index> [local-fib-table <index>]";
+
+static u8 *
+clb_format_srv6_t_m_gtp4_dt (u8 * s, va_list * args)
+{
+  srv6_t_gtp4_dt_param_t *ls_mem = va_arg (*args, void *);
+
+  s = format (s, "SRv6 Transit gtp4.dt\n\t");
+
+  if (ls_mem->type == SRV6_GTP4_DT4)
+    s = format (s, " Type GTP4.DT4 fib-table %u\n", ls_mem->fib4_index);
+  else if (ls_mem->type == SRV6_GTP4_DT6)
+    s = format (s, " Type GTP4.DT6, fib-table %u, local-fib-table %u\n",
+		ls_mem->fib6_index, ls_mem->local_fib_index);
+  else if (ls_mem->type == SRV6_GTP4_DT46)
+    s = format (s, " Type GTP4.DT46, fib-table %u, local-fib-table %u\n",
+		ls_mem->fib6_index, ls_mem->local_fib_index);
+  else
+    s = format (s, "\n");
+
+  return s;
+}
+
+static uword
+clb_unformat_srv6_t_m_gtp4_dt (unformat_input_t * input, va_list * args)
+{
+  void **plugin_mem_p = va_arg (*args, void **);
+  srv6_t_gtp4_dt_param_t *ls_mem;
+  u32 fib_index = 0;
+  u32 local_fib_index = 0;
+  u32 type;
+
+  if (unformat (input, "t.m.gtp4.dt4 fib-table %u", &fib_index))
+    {
+      type = SRV6_GTP4_DT4;
+    }
+  else if (unformat (input, "t.m.gtp4.dt6 fib-table %u local-fib-table %u",
+		     &fib_index, &local_fib_index))
+    {
+      type = SRV6_GTP4_DT6;
+    }
+  else if (unformat (input, "t.m.gtp4.dt46 fib-table %u local-fib-table %u",
+		     &fib_index, &local_fib_index))
+    {
+      type = SRV6_GTP4_DT46;
+    }
+  else
+    {
+      return 0;
+    }
+
+  ls_mem = clib_mem_alloc_aligned_at_offset (sizeof *ls_mem, 0, 0, 1);
+  clib_memset (ls_mem, 0, sizeof *ls_mem);
+  *plugin_mem_p = ls_mem;
+
+  ls_mem->fib4_index = fib_table_find (FIB_PROTOCOL_IP4, fib_index);
+  ls_mem->fib6_index = fib_table_find (FIB_PROTOCOL_IP6, fib_index);
+
+  if (type == SRV6_GTP4_DT6 || type == SRV6_GTP4_DT46)
+    {
+      ls_mem->local_fib_index =
+	fib_table_find (FIB_PROTOCOL_IP6, local_fib_index);
+    }
+
+  ls_mem->type = type;
+
+  return 1;
+}
+
+static int
+clb_creation_srv6_t_m_gtp4_dt (ip6_sr_policy_t * sr_policy)
+{
+  return 0;
+}
+
+static int
+clb_removal_srv6_t_m_gtp4_dt (ip6_sr_policy_t * sr_policy)
+{
+  srv6_t_gtp4_dt_param_t *ls_mem;
+
+  ls_mem = (srv6_t_gtp4_dt_param_t *) sr_policy->plugin_mem;
+
+  clib_mem_free (ls_mem);
+
+  return 0;
+}
+
+static clib_error_t *
+srv6_t_m_gtp4_dt_init (vlib_main_t * vm)
+{
+  srv6_t_main_v4_dt_t *sm = &srv6_t_main_v4_dt;
+  dpo_type_t dpo_type;
+  vlib_node_t *node;
+  int rc;
+
+  sm->vlib_main = vm;
+  sm->vnet_main = vnet_get_main ();
+
+  node = vlib_get_node_by_name (vm, (u8 *) "srv6-t-m-gtp4-dt");
+  sm->t_m_gtp4_dt_node_index = node->index;
+
+  node = vlib_get_node_by_name (vm, (u8 *) "error-drop");
+  sm->error_node_index = node->index;
+
+  dpo_type = dpo_register_new_type (&dpo_vft, dpo_nodes);
+
+  rc = sr_policy_register_function (vm, fn_name, keyword_str, def_str, param_str, 128,	//prefix len
+				    &dpo_type,
+				    clb_format_srv6_t_m_gtp4_dt,
+				    clb_unformat_srv6_t_m_gtp4_dt,
+				    clb_creation_srv6_t_m_gtp4_dt,
+				    clb_removal_srv6_t_m_gtp4_dt);
+  if (rc < 0)
+    clib_error_return (0, "SRv6 Transit GTP4.DT Policy function"
+		       "couldn't be registered");
+  return 0;
+}
+
+/* *INDENT-OFF* */
+VNET_FEATURE_INIT (srv6_t_m_gtp4_dt, static) =
+{
+  .arc_name = "ip4-unicast",
+  .node_name = "srv6-t-m-gtp4-dt",
+  .runs_before = 0,
+};
+
+VLIB_INIT_FUNCTION (srv6_t_m_gtp4_dt_init);
+/* *INDENT-ON* */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */
diff --git a/src/plugins/srv6-mobile/gtp6_dt.c b/src/plugins/srv6-mobile/gtp6_dt.c
new file mode 100644
index 00000000000..cbd2327cc47
--- /dev/null
+++ b/src/plugins/srv6-mobile/gtp6_dt.c
@@ -0,0 +1,199 @@
+/*
+ * srv6_end_m_gtp6_dt.c
+ *
+ * Copyright (c) 2019 Arrcus Inc and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <vnet/vnet.h>
+#include <vnet/adj/adj.h>
+#include <vnet/fib/fib_table.h>
+#include <vnet/plugin/plugin.h>
+#include <vpp/app/version.h>
+#include <srv6-mobile/mobile.h>
+
+srv6_end_main_v6_dt_t srv6_end_main_v6_dt;
+
+static void
+clb_dpo_lock_srv6_end_m_gtp6_dt (dpo_id_t * dpo)
+{
+}
+
+static void
+clb_dpo_unlock_srv6_end_m_gtp6_dt (dpo_id_t * dpo)
+{
+}
+
+static u8 *
+clb_dpo_format_srv6_end_m_gtp6_dt (u8 * s, va_list * args)
+{
+  index_t index = va_arg (*args, index_t);
+  CLIB_UNUSED (u32 indent) = va_arg (*args, u32);
+
+  return (format (s, "SR: dynamic_proxy_index:[%u]", index));
+}
+
+const static dpo_vft_t dpo_vft = {
+  .dv_lock = clb_dpo_lock_srv6_end_m_gtp6_dt,
+  .dv_unlock = clb_dpo_unlock_srv6_end_m_gtp6_dt,
+  .dv_format = clb_dpo_format_srv6_end_m_gtp6_dt,
+};
+
+const static char *const srv6_end_m_gtp6_dt_nodes[] = {
+  "srv6-end-m-gtp6-dt",
+  NULL,
+};
+
+const static char *const *const dpo_nodes[DPO_PROTO_NUM] = {
+  [DPO_PROTO_IP6] = srv6_end_m_gtp6_dt_nodes,
+};
+
+static u8 fn_name[] = "SRv6-End.M.GTP6.DT-plugin";
+static u8 keyword_str[] = "end.m.gtp6.dt";
+static u8 def_str[] = "Endpoint function with DT for IPv6/GTP tunnel";
+static u8 param_str[] = "fib-index <index> [local-fib-table <index>]";
+
+static u8 *
+clb_format_srv6_end_m_gtp6_dt (u8 * s, va_list * args)
+{
+  srv6_end_gtp6_dt_param_t *ls_mem = va_arg (*args, void *);
+
+  s = format (s, "SRv6 End gtp6.dt\n\t");
+
+  if (ls_mem->type == SRV6_GTP6_DT4)
+    s = format (s, " Type GTP6.DT4 fib-table %u\n", ls_mem->fib4_index);
+  else if (ls_mem->type == SRV6_GTP6_DT6)
+    s = format (s, " Type GTP6.DT6, fib-table %u, local-fib-table %u\n",
+		ls_mem->fib6_index, ls_mem->local_fib_index);
+  else if (ls_mem->type == SRV6_GTP6_DT46)
+    s = format (s, " Type GTP6.DT46, fib-table %u, local-fib-table %u\n",
+		ls_mem->fib6_index, ls_mem->local_fib_index);
+  else
+    s = format (s, "\n");
+
+  return s;
+}
+
+static uword
+clb_unformat_srv6_end_m_gtp6_dt (unformat_input_t * input, va_list * args)
+{
+  void **plugin_mem_p = va_arg (*args, void **);
+  srv6_end_gtp6_dt_param_t *ls_mem;
+  u32 fib_index = 0;
+  u32 local_fib_index = 0;
+  u32 type;
+
+  if (unformat (input, "end.m.gtp6.dt4 fib-table %u", &fib_index))
+    {
+      type = SRV6_GTP6_DT4;
+    }
+  else if (unformat (input, "end.m.gtp6.dt6 fib-table %u local-fib-table %u",
+		     &fib_index, &local_fib_index))
+    {
+      type = SRV6_GTP6_DT6;
+    }
+  else if (unformat (input, "end.m.gtp6.dt46 fib-table %u local-fib-table %u",
+		     &fib_index, &local_fib_index))
+    {
+      type = SRV6_GTP6_DT46;
+    }
+  else
+    {
+      return 0;
+    }
+
+  ls_mem = clib_mem_alloc_aligned_at_offset (sizeof *ls_mem, 0, 0, 1);
+  clib_memset (ls_mem, 0, sizeof *ls_mem);
+  *plugin_mem_p = ls_mem;
+
+  ls_mem->fib4_index = fib_table_find (FIB_PROTOCOL_IP4, fib_index);
+  ls_mem->fib6_index = fib_table_find (FIB_PROTOCOL_IP6, fib_index);
+
+  if (type == SRV6_GTP6_DT6 || type == SRV6_GTP6_DT46)
+    {
+      ls_mem->local_fib_index =
+	fib_table_find (FIB_PROTOCOL_IP6, local_fib_index);
+    }
+
+  ls_mem->type = type;
+
+  return 1;
+}
+
+static int
+clb_creation_srv6_end_m_gtp6_dt (ip6_sr_localsid_t * localsid)
+{
+  return 0;
+}
+
+static int
+clb_removal_srv6_end_m_gtp6_dt (ip6_sr_localsid_t * localsid)
+{
+  srv6_end_gtp6_dt_param_t *ls_mem;
+
+  ls_mem = localsid->plugin_mem;
+
+  clib_mem_free (ls_mem);
+
+  return 0;
+}
+
+static clib_error_t *
+srv6_end_m_gtp6_dt_init (vlib_main_t * vm)
+{
+  srv6_end_main_v6_dt_t *sm = &srv6_end_main_v6_dt;
+  dpo_type_t dpo_type;
+  vlib_node_t *node;
+  int rc;
+
+  sm->vlib_main = vm;
+  sm->vnet_main = vnet_get_main ();
+
+  node = vlib_get_node_by_name (vm, (u8 *) "srv6-end-m-gtp6-dt");
+  sm->end_m_gtp6_dt_node_index = node->index;
+
+  node = vlib_get_node_by_name (vm, (u8 *) "error-drop");
+  sm->error_node_index = node->index;
+
+  dpo_type = dpo_register_new_type (&dpo_vft, dpo_nodes);
+
+  rc = sr_localsid_register_function (vm, fn_name, keyword_str, def_str, param_str, 128,	//prefix len
+				      &dpo_type,
+				      clb_format_srv6_end_m_gtp6_dt,
+				      clb_unformat_srv6_end_m_gtp6_dt,
+				      clb_creation_srv6_end_m_gtp6_dt,
+				      clb_removal_srv6_end_m_gtp6_dt);
+  if (rc < 0)
+    clib_error_return (0, "SRv6 Endpoint GTP6.DT LocalSID function"
+		       "couldn't be registered");
+  return 0;
+}
+
+/* *INDENT-OFF* */
+VNET_FEATURE_INIT (srv6_end_m_gtp6_dt, static) =
+{
+  .arc_name = "ip6-unicast",
+  .node_name = "srv6-end-m-gtp6-dt",
+  .runs_before = 0,
+};
+
+VLIB_INIT_FUNCTION (srv6_end_m_gtp6_dt_init);
+/* *INDENT-ON* */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */
diff --git a/src/plugins/srv6-mobile/mobile.h b/src/plugins/srv6-mobile/mobile.h
index 460cbe17ef1..517e7c8f84c 100644
--- a/src/plugins/srv6-mobile/mobile.h
+++ b/src/plugins/srv6-mobile/mobile.h
@@ -42,6 +42,11 @@
 #define SRV6_GTP6_DT6		2
 #define SRV6_GTP6_DT46		3
 
+#define SRV6_GTP4_UNKNOW	0
+#define SRV6_GTP4_DT4		1
+#define SRV6_GTP4_DT6		2
+#define SRV6_GTP4_DT46		3
+
 #if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
 #define BITALIGN2(A,B)          A; B
 #define BITALIGN3(A,B,C)        A; B; C
@@ -59,6 +64,19 @@
 #define SRH_TAG_ERROR_INDICATION        0x0002
 #define SRH_TAG_END_MARKER              0x0001
 
+#define GTPU_RECOVERY_IE_TYPE		0x0e
+
+#define GTPU_IE_MAX_SIZ			256
+#define SRH_TLV_USER_PLANE_CONTAINER	0x0a	/* tentative */
+
+/* *INDENT-OFF* */
+typedef struct
+{
+  u8 type;
+  u8 restart_counter;
+} __attribute__ ((packed)) gtpu_recovery_ie;
+/* *INDENT-ON* */
+
 /* *INDENT-OFF* */
 typedef struct
 {
@@ -145,6 +163,17 @@ typedef struct
 
 #define GTPU_PT_GTP   (1<<4)
 
+/* *INDENT-OFF* */
+typedef struct
+{
+  u8 type;
+  u8 length;
+  u8 value[0];
+} __attribute__ ((packed)) user_plane_sub_tlv_t;
+/* *INDENT-ON* */
+
+#define USER_PLANE_SUB_TLV_IE	0x01
+
 typedef struct srv6_end_gtp6_param_s
 {
   u8 nhtype;
@@ -153,6 +182,24 @@ typedef struct srv6_end_gtp6_param_s
   u32 sr_prefixlen;
 } srv6_end_gtp6_param_t;
 
+typedef struct srv6_end_gtp6_dt_param_s
+{
+  u8 type;
+
+  u32 fib4_index;
+  u32 fib6_index;
+  u32 local_fib_index;
+} srv6_end_gtp6_dt_param_t;
+
+typedef struct srv6_t_gtp4_dt_param_s
+{
+  u8 type;
+
+  u32 fib4_index;
+  u32 fib6_index;
+  u32 local_fib_index;
+} srv6_t_gtp4_dt_param_t;
+
 typedef struct srv6_end_gtp4_param_s
 {
   u8 nhtype;
@@ -238,6 +285,30 @@ typedef struct srv6_end_main_v6_decap_di_s
 extern srv6_end_main_v6_decap_di_t srv6_end_main_v6_decap_di;
 extern vlib_node_registration_t srv6_end_m_gtp6_d_di;
 
+typedef struct srv6_end_main_v6_dt_s
+{
+  vlib_main_t *vlib_main;
+  vnet_main_t *vnet_main;
+
+  u32 end_m_gtp6_dt_node_index;
+  u32 error_node_index;
+} srv6_end_main_v6_dt_t;
+
+extern srv6_end_main_v6_dt_t srv6_end_main_v6_dt;
+extern vlib_node_registration_t srv6_end_m_gtp6_dt;
+
+typedef struct srv6_t_main_v4_dt_s
+{
+  vlib_main_t *vlib_main;
+  vnet_main_t *vnet_main;
+
+  u32 t_m_gtp4_dt_node_index;
+  u32 error_node_index;
+} srv6_t_main_v4_dt_t;
+
+extern srv6_t_main_v4_dt_t srv6_t_main_v4_dt;
+extern vlib_node_registration_t srv6_t_m_gtp4_dt;
+
 #endif /* __included_srv6_end_h__ */
 
 /*
diff --git a/src/plugins/srv6-mobile/node.c b/src/plugins/srv6-mobile/node.c
index 6eafefd3f5b..6d3240e77c4 100644
--- a/src/plugins/srv6-mobile/node.c
+++ b/src/plugins/srv6-mobile/node.c
@@ -129,6 +129,14 @@ format_srv6_end_rewrite_trace6 (u8 * s, va_list * args)
   _(M_GTP6_D_DI_PACKETS, "srv6 End.M.GTP6.D.DI packets") \
   _(M_GTP6_D_DI_BAD_PACKETS, "srv6 End.M.GTP6.D.DI bad packets")
 
+#define foreach_srv6_end_v6_dt_error \
+  _(M_GTP6_DT_PACKETS, "srv6 End.M.GTP6.DT packets") \
+  _(M_GTP6_DT_BAD_PACKETS, "srv6 End.M.GTP6.DT bad packets")
+
+#define foreach_srv6_t_v4_dt_error \
+  _(M_GTP4_DT_PACKETS, "srv6 T.M.GTP4.DT packets") \
+  _(M_GTP4_DT_BAD_PACKETS, "srv6 T.M.GTP4.DT bad packets")
+
 typedef enum
 {
 #define _(sym,str) SRV6_END_ERROR_##sym,
@@ -169,6 +177,22 @@ typedef enum
     SRV6_END_N_V6_D_DI_ERROR,
 } srv6_end_error_v6_d_di_t;
 
+typedef enum
+{
+#define _(sym,str) SRV6_END_ERROR_##sym,
+  foreach_srv6_end_v6_dt_error
+#undef _
+    SRV6_END_N_V6_DT_ERROR,
+} srv6_end_error_v6_dt_t;
+
+typedef enum
+{
+#define _(sym,str) SRV6_T_ERROR_##sym,
+  foreach_srv6_t_v4_dt_error
+#undef _
+    SRV6_T_N_V4_DT_ERROR,
+} srv6_t_error_v4_dt_t;
+
 static char *srv6_end_error_v4_strings[] = {
 #define _(sym,string) string,
   foreach_srv6_end_v4_error
@@ -199,6 +223,18 @@ static char *srv6_end_error_v6_d_di_strings[] = {
 #undef _
 };
 
+static char *srv6_end_error_v6_dt_strings[] = {
+#define _(sym,string) string,
+  foreach_srv6_end_v6_dt_error
+#undef _
+};
+
+static char *srv6_t_error_v4_dt_strings[] = {
+#define _(sym,string) string,
+  foreach_srv6_t_v4_dt_error
+#undef _
+};
+
 typedef enum
 {
   SRV6_END_M_GTP4_E_NEXT_DROP,
@@ -234,6 +270,22 @@ typedef enum
   SRV6_END_M_GTP6_D_DI_N_NEXT,
 } srv6_end_m_gtp6_d_di_next_t;
 
+typedef enum
+{
+  SRV6_END_M_GTP6_DT_NEXT_DROP,
+  SRV6_END_M_GTP6_DT_NEXT_LOOKUP4,
+  SRV6_END_M_GTP6_DT_NEXT_LOOKUP6,
+  SRV6_END_M_GTP6_DT_N_NEXT,
+} srv6_end_m_gtp6_dt_next_t;
+
+typedef enum
+{
+  SRV6_T_M_GTP4_DT_NEXT_DROP,
+  SRV6_T_M_GTP4_DT_NEXT_LOOKUP4,
+  SRV6_T_M_GTP4_DT_NEXT_LOOKUP6,
+  SRV6_T_M_GTP4_DT_N_NEXT,
+} srv6_t_m_gtp4_dt_next_t;
+
 static inline u16
 hash_uword_to_u16 (uword * key)
 {
@@ -345,33 +397,16 @@ VLIB_NODE_FN (srv6_end_m_gtp4_e) (vlib_main_t * vm,
 	      uword key;
 	      u16 port;
 	      ip4_address_t dst4;
+	      u16 ie_size = 0;
+	      u8 ie_buf[GTPU_IE_MAX_SIZ];
 	      void *p;
+	      uword plen;
 
-	      // we need to be sure there is enough space before
-	      // ip6srv0 header, there is some extra space
-	      // in the pre_data area for this kind of
-	      // logic
-
-	      // jump over variable length data
-	      // not sure about the length
 	      if (ip6srv0->ip.protocol == IPPROTO_IPV6_ROUTE)
 		{
 		  tag = ip6srv0->sr.tag;
-
-		  vlib_buffer_advance (b0,
-				       (word) sizeof (ip6srv_combo_header_t) +
-				       ip6srv0->sr.length * 8);
-		}
-	      else
-		{
-		  vlib_buffer_advance (b0, (word) sizeof (ip6_header_t));
 		}
 
-	      // get length of encapsulated IPv6 packet (the remaining part)
-	      p = vlib_buffer_get_current (b0);
-
-	      len0 = vlib_buffer_length_in_chain (vm, b0);
-
 	      offset = ls0->localsid_prefix_len / 8;
 	      shift = ls0->localsid_prefix_len % 8;
 
@@ -443,6 +478,58 @@ VLIB_NODE_FN (srv6_end_m_gtp4_e) (vlib_main_t * vm,
 		{
 		  hdrlen = sizeof (gtpu_exthdr_t);
 		}
+
+	      if (PREDICT_FALSE (gtpu_type == GTPU_TYPE_ECHO_REPLY))
+		{
+		  hdrlen += sizeof (gtpu_recovery_ie);
+		}
+
+	      if (PREDICT_FALSE (gtpu_type == GTPU_TYPE_ERROR_INDICATION))
+		{
+		  ip6_sr_tlv_t *tlv;
+		  u16 ext_len;
+
+		  ext_len = ip6srv0->sr.length * 8;
+
+		  if (ext_len >
+		      sizeof (ip6_address_t) * (ip6srv0->sr.last_entry + 1))
+		    {
+		      tlv =
+			(ip6_sr_tlv_t *) ((u8 *) & ip6srv0->sr +
+					  sizeof (ip6_sr_header_t) +
+					  sizeof (ip6_address_t) *
+					  (ip6srv0->sr.last_entry + 1));
+
+		      if (tlv->type == SRH_TLV_USER_PLANE_CONTAINER)
+			{
+			  user_plane_sub_tlv_t *sub_tlv;
+
+			  sub_tlv = (user_plane_sub_tlv_t *) tlv->value;
+
+			  ie_size = sub_tlv->length;
+			  clib_memcpy_fast (ie_buf, sub_tlv->value, ie_size);
+
+			  hdrlen += ie_size;
+			}
+		    }
+		}
+
+	      if (ip6srv0->ip.protocol == IPPROTO_IPV6_ROUTE)
+		{
+		  vlib_buffer_advance (b0,
+				       (word) sizeof (ip6srv_combo_header_t) +
+				       ip6srv0->sr.length * 8);
+		}
+	      else
+		{
+		  vlib_buffer_advance (b0, (word) sizeof (ip6_header_t));
+		}
+
+	      // get length of encapsulated IPv6 packet (the remaining part)
+	      p = vlib_buffer_get_current (b0);
+
+	      plen = len0 = vlib_buffer_length_in_chain (vm, b0);
+
 	      len0 += hdrlen;
 
 	      hdrlen += sizeof (ip4_gtpu_header_t);
@@ -499,6 +586,28 @@ VLIB_NODE_FN (srv6_end_m_gtp4_e) (vlib_main_t * vm,
 		  hdr0->gtpu.ext->seq = seq;
 		  hdr0->gtpu.ext->npdu_num = 0;
 		  hdr0->gtpu.ext->nextexthdr = 0;
+
+		  if (gtpu_type == GTPU_TYPE_ECHO_REPLY)
+		    {
+		      gtpu_recovery_ie *recovery;
+
+		      recovery =
+			(gtpu_recovery_ie *) ((u8 *) hdr0 +
+					      (hdrlen -
+					       sizeof (gtpu_recovery_ie)));
+		      recovery->type = GTPU_RECOVERY_IE_TYPE;
+		      recovery->restart_counter = 0;
+		    }
+		  else if (gtpu_type == GTPU_TYPE_ERROR_INDICATION)
+		    {
+		      if (ie_size)
+			{
+			  u8 *ie_ptr;
+
+			  ie_ptr = (u8 *) ((u8 *) hdr0 + (hdrlen - ie_size));
+			  clib_memcpy_fast (ie_ptr, ie_buf, ie_size);
+			}
+		    }
 		}
 
 	      offset = ls_param->v4src_position / 8;
@@ -523,7 +632,7 @@ VLIB_NODE_FN (srv6_end_m_gtp4_e) (vlib_main_t * vm,
 		    }
 		}
 
-	      key = hash_memory (p, len0, 0);
+	      key = hash_memory (p, plen < 40 ? plen : 40, 0);
 	      port = hash_uword_to_u16 (&key);
 	      hdr0->udp.src_port = port;
 
@@ -659,6 +768,9 @@ VLIB_NODE_FN (srv6_t_m_gtp4_d) (vlib_main_t * vm,
 	      u32 offset, shift, index;
 	      ip6srv_combo_header_t *ip6srv;
 	      gtpu_pdu_session_t *sess = NULL;
+	      u16 ie_size = 0;
+	      u16 tlv_siz = 0;
+	      u8 ie_buf[GTPU_IE_MAX_SIZ];
 
 	      // Decap from GTP-U.
 	      hdr = (ip4_gtpu_header_t *) ip4;
@@ -784,6 +896,24 @@ VLIB_NODE_FN (srv6_t_m_gtp4_d) (vlib_main_t * vm,
 		    }
 		}
 
+	      if (PREDICT_FALSE (gtpu_type == GTPU_TYPE_ERROR_INDICATION))
+		{
+		  u16 payload_len;
+
+		  payload_len = clib_net_to_host_u16 (hdr->gtpu.length);
+		  if (payload_len != 0
+		      && payload_len > hdr_len - sizeof (ip4_gtpu_header_t))
+		    {
+		      u8 *ies;
+
+		      ies = (u8 *) ((u8 *) hdr + hdr_len);
+		      ie_size =
+			payload_len - (hdr_len - sizeof (ip4_gtpu_header_t));
+		      clib_memcpy_fast (ie_buf, ies, ie_size);
+		      hdr_len += ie_size;
+		    }
+		}
+
 	      src6 = ls_param->v6src_prefix;
 
 	      offset = ls_param->v6src_prefixlen / 8;
@@ -848,6 +978,16 @@ VLIB_NODE_FN (srv6_t_m_gtp4_d) (vlib_main_t * vm,
 		    }
 		}
 
+	      if (ie_size)
+		{
+		  tlv_siz =
+		    sizeof (ip6_sr_tlv_t) + sizeof (user_plane_sub_tlv_t) +
+		    ie_size;
+
+		  tlv_siz = (tlv_siz & ~0x07) + (tlv_siz & 0x07 ? 0x08 : 0x0);
+		  hdr_len += tlv_siz;
+		}
+
 	      vlib_buffer_advance (b0, -(word) hdr_len);
 	      ip6srv = vlib_buffer_get_current (b0);
 
@@ -1015,6 +1155,25 @@ VLIB_NODE_FN (srv6_t_m_gtp4_d) (vlib_main_t * vm,
 
 	      ip6srv->ip.src_address = src6;
 
+	      if (PREDICT_FALSE (ie_size))
+		{
+		  ip6_sr_tlv_t *tlv;
+		  user_plane_sub_tlv_t *sub_tlv;
+
+		  tlv =
+		    (ip6_sr_tlv_t *) ((u8 *) ip6srv + (hdr_len - tlv_siz));
+		  tlv->type = SRH_TLV_USER_PLANE_CONTAINER;
+		  tlv->length = tlv_siz - sizeof (ip6_sr_tlv_t);
+		  clib_memset (tlv->value, 0, tlv->length);
+
+		  sub_tlv = (user_plane_sub_tlv_t *) tlv->value;
+		  sub_tlv->type = USER_PLANE_SUB_TLV_IE;
+		  sub_tlv->length = ie_size;
+		  clib_memcpy_fast (sub_tlv->value, ie_buf, ie_size);
+
+		  ip6srv->sr.length += tlv_siz / 8;
+		}
+
 	      ip6srv->ip.payload_length =
 		clib_host_to_net_u16 (len0 + hdr_len - sizeof (ip6_header_t));
 
@@ -1057,8 +1216,8 @@ VLIB_REGISTER_NODE (srv6_end_m_gtp4_e) =
     srv6_end_error_v4_strings,.n_next_nodes =
     SRV6_END_M_GTP4_E_N_NEXT,.next_nodes =
   {
-  [SRV6_END_M_GTP4_E_NEXT_DROP] = "error-drop",
-      [SRV6_END_M_GTP4_E_NEXT_LOOKUP] = "ip4-lookup",}
+  [SRV6_END_M_GTP4_E_NEXT_DROP] =
+      "error-drop",[SRV6_END_M_GTP4_E_NEXT_LOOKUP] = "ip4-lookup",}
 ,};
 
 VLIB_REGISTER_NODE (srv6_t_m_gtp4_d) =
@@ -1069,8 +1228,8 @@ VLIB_REGISTER_NODE (srv6_t_m_gtp4_d) =
     srv6_t_error_v4_d_strings,.n_next_nodes =
     SRV6_T_M_GTP4_D_N_NEXT,.next_nodes =
   {
-  [SRV6_T_M_GTP4_D_NEXT_DROP] = "error-drop",
-      [SRV6_T_M_GTP4_D_NEXT_LOOKUP] = "ip6-lookup",}
+  [SRV6_T_M_GTP4_D_NEXT_DROP] =
+      "error-drop",[SRV6_T_M_GTP4_D_NEXT_LOOKUP] = "ip6-lookup",}
 ,};
 
 // Function for SRv6 GTP6.E function
@@ -1110,6 +1269,7 @@ VLIB_NODE_FN (srv6_end_m_gtp6_e) (vlib_main_t * vm,
 	  u16 port;
 	  u16 tag;
 	  void *p;
+	  uword plen;
 
 	  u32 next0 = SRV6_END_M_GTP6_E_NEXT_LOOKUP;
 
@@ -1150,16 +1310,6 @@ VLIB_NODE_FN (srv6_end_m_gtp6_e) (vlib_main_t * vm,
 	      // in the pre_data area for this kind of
 	      // logic
 
-	      // jump over variable length data
-	      // not sure about the length
-	      vlib_buffer_advance (b0, (word) sizeof (ip6srv_combo_header_t) +
-				   ip6srv0->sr.length * 8);
-
-	      // get length of encapsulated IPv6 packet (the remaining part)
-	      p = vlib_buffer_get_current (b0);
-
-	      len0 = vlib_buffer_length_in_chain (vm, b0);
-
 	      u32 teid = 0;
 	      u8 *teid8p = (u8 *) & teid;
 	      u8 qfi = 0;
@@ -1168,6 +1318,8 @@ VLIB_NODE_FN (srv6_end_m_gtp6_e) (vlib_main_t * vm,
 	      u16 index;
 	      u16 offset, shift;
 	      u32 hdrlen = 0;
+	      u16 ie_size = 0;
+	      u8 ie_buf[GTPU_IE_MAX_SIZ];
 
 	      index = ls0->localsid_prefix_len;
 	      index += 8;
@@ -1234,7 +1386,52 @@ VLIB_NODE_FN (srv6_end_m_gtp6_e) (vlib_main_t * vm,
 		  hdrlen = sizeof (gtpu_exthdr_t);
 		}
 
+	      if (gtpu_type == GTPU_TYPE_ECHO_REPLY)
+		{
+		  hdrlen += sizeof (gtpu_recovery_ie);
+		}
+
+	      if (PREDICT_FALSE (gtpu_type == GTPU_TYPE_ERROR_INDICATION))
+		{
+		  ip6_sr_tlv_t *tlv;
+		  u16 ext_len;
+
+		  ext_len = ip6srv0->sr.length * 8;
+
+		  if (ext_len >
+		      sizeof (ip6_address_t) * (ip6srv0->sr.last_entry + 1))
+		    {
+		      tlv =
+			(ip6_sr_tlv_t *) ((u8 *) & ip6srv0->sr +
+					  sizeof (ip6_sr_header_t) +
+					  sizeof (ip6_address_t) *
+					  (ip6srv0->sr.last_entry + 1));
+
+		      if (tlv->type == SRH_TLV_USER_PLANE_CONTAINER)
+			{
+			  user_plane_sub_tlv_t *sub_tlv;
+
+			  sub_tlv = (user_plane_sub_tlv_t *) tlv->value;
+
+			  ie_size = sub_tlv->length;
+			  clib_memcpy_fast (ie_buf, sub_tlv->value, ie_size);
+
+			  hdrlen += ie_size;
+			}
+		    }
+		}
+
+	      vlib_buffer_advance (b0,
+				   (word) sizeof (ip6srv_combo_header_t) +
+				   ip6srv0->sr.length * 8);
+
+	      // get length of encapsulated IPv6 packet (the remaining part)
+	      p = vlib_buffer_get_current (b0);
+
+	      plen = len0 = vlib_buffer_length_in_chain (vm, b0);
+
 	      len0 += hdrlen;
+
 	      hdrlen += sizeof (ip6_gtpu_header_t);
 
 	      vlib_buffer_advance (b0, -(word) hdrlen);
@@ -1285,6 +1482,28 @@ VLIB_NODE_FN (srv6_end_m_gtp6_e) (vlib_main_t * vm,
 		  hdr0->gtpu.ext->seq = seq;
 		  hdr0->gtpu.ext->npdu_num = 0;
 		  hdr0->gtpu.ext->nextexthdr = 0;
+
+		  if (gtpu_type == GTPU_TYPE_ECHO_REPLY)
+		    {
+		      gtpu_recovery_ie *recovery;
+
+		      recovery =
+			(gtpu_recovery_ie *) ((u8 *) hdr0 +
+					      (hdrlen -
+					       sizeof (gtpu_recovery_ie)));
+		      recovery->type = GTPU_RECOVERY_IE_TYPE;
+		      recovery->restart_counter = 0;
+		    }
+		  else if (gtpu_type == GTPU_TYPE_ERROR_INDICATION)
+		    {
+		      if (ie_size)
+			{
+			  u8 *ie_ptr;
+
+			  ie_ptr = (u8 *) ((u8 *) hdr0 + (hdrlen - ie_size));
+			  clib_memcpy_fast (ie_ptr, ie_buf, ie_size);
+			}
+		    }
 		}
 
 	      hdr0->udp.length = clib_host_to_net_u16 (len0 +
@@ -1305,7 +1524,7 @@ VLIB_NODE_FN (srv6_end_m_gtp6_e) (vlib_main_t * vm,
 							       (gtpu_header_t));
 
 	      // UDP source port.
-	      key = hash_memory (p, len0, 0);
+	      key = hash_memory (p, plen < 40 ? plen : 40, 0);
 	      port = hash_uword_to_u16 (&key);
 	      hdr0->udp.src_port = port;
 
@@ -1390,6 +1609,9 @@ VLIB_NODE_FN (srv6_end_m_gtp6_d) (vlib_main_t * vm,
 	  u32 hdrlen;
 	  ip6_header_t *encap = NULL;
 	  gtpu_pdu_session_t *sess = NULL;
+	  u16 ie_size = 0;
+	  u16 tlv_siz = 0;
+	  u8 ie_buf[GTPU_IE_MAX_SIZ];
 
 	  u32 next0 = SRV6_END_M_GTP6_D_NEXT_LOOKUP;
 
@@ -1533,6 +1755,24 @@ VLIB_NODE_FN (srv6_end_m_gtp6_d) (vlib_main_t * vm,
 		    }
 		}
 
+	      if (PREDICT_FALSE (gtpu_type == GTPU_TYPE_ERROR_INDICATION))
+		{
+		  u16 payload_len;
+
+		  payload_len = clib_net_to_host_u16 (hdr0->gtpu.length);
+		  if (payload_len != 0
+		      && payload_len > hdrlen - sizeof (ip6_gtpu_header_t))
+		    {
+		      u8 *ies;
+
+		      ies = (u8 *) ((u8 *) hdr0 + hdrlen);
+		      ie_size =
+			payload_len - (hdrlen - sizeof (ip6_gtpu_header_t));
+		      clib_memcpy_fast (ie_buf, ies, ie_size);
+		      hdrlen += ie_size;
+		    }
+		}
+
 	      // jump over variable length data
 	      vlib_buffer_advance (b0, (word) hdrlen);
 
@@ -1585,6 +1825,16 @@ VLIB_NODE_FN (srv6_end_m_gtp6_d) (vlib_main_t * vm,
 		    }
 		}
 
+	      if (ie_size)
+		{
+		  tlv_siz =
+		    sizeof (ip6_sr_tlv_t) + sizeof (user_plane_sub_tlv_t) +
+		    ie_size;
+
+		  tlv_siz = (tlv_siz & ~0x07) + (tlv_siz & 0x07 ? 0x08 : 0x0);
+		  hdr_len += tlv_siz;
+		}
+
 	      // jump back to data[0] or pre_data if required
 	      vlib_buffer_advance (b0, -(word) hdr_len);
 
@@ -1753,6 +2003,25 @@ VLIB_NODE_FN (srv6_end_m_gtp6_d) (vlib_main_t * vm,
 		    }
 		}
 
+	      if (PREDICT_FALSE (ie_size))
+		{
+		  ip6_sr_tlv_t *tlv;
+		  user_plane_sub_tlv_t *sub_tlv;
+
+		  tlv =
+		    (ip6_sr_tlv_t *) ((u8 *) ip6srv + (hdr_len - tlv_siz));
+		  tlv->type = SRH_TLV_USER_PLANE_CONTAINER;
+		  tlv->length = tlv_siz - sizeof (ip6_sr_tlv_t);
+		  clib_memset (tlv->value, 0, tlv->length);
+
+		  sub_tlv = (user_plane_sub_tlv_t *) tlv->value;
+		  sub_tlv->type = USER_PLANE_SUB_TLV_IE;
+		  sub_tlv->length = ie_size;
+		  clib_memcpy_fast (sub_tlv->value, ie_buf, ie_size);
+
+		  ip6srv->sr.length += tlv_siz / 8;
+		}
+
 	      ip6srv->ip.payload_length =
 		clib_host_to_net_u16 (len0 + hdr_len - sizeof (ip6_header_t));
 
@@ -1843,6 +2112,9 @@ VLIB_NODE_FN (srv6_end_m_gtp6_d_di) (vlib_main_t * vm,
 	  u32 hdrlen;
 	  ip6_header_t *encap = NULL;
 	  gtpu_pdu_session_t *sess;
+	  u16 ie_size = 0;
+	  u16 tlv_siz = 0;
+	  u8 ie_buf[GTPU_IE_MAX_SIZ];
 
 	  u32 next0 = SRV6_END_M_GTP6_D_DI_NEXT_LOOKUP;
 
@@ -1985,6 +2257,24 @@ VLIB_NODE_FN (srv6_end_m_gtp6_d_di) (vlib_main_t * vm,
 		    }
 		}
 
+	      if (PREDICT_FALSE (gtpu_type == GTPU_TYPE_ERROR_INDICATION))
+		{
+		  u16 payload_len;
+
+		  payload_len = clib_net_to_host_u16 (hdr0->gtpu.length);
+		  if (payload_len != 0
+		      && payload_len > hdrlen - sizeof (ip6_gtpu_header_t))
+		    {
+		      u8 *ies;
+
+		      ies = (u8 *) ((u8 *) hdr0 + hdrlen);
+		      ie_size =
+			payload_len - (hdrlen - sizeof (ip6_gtpu_header_t));
+		      clib_memcpy_fast (ie_buf, ies, ie_size);
+		      hdrlen += ie_size;
+		    }
+		}
+
 	      // jump over variable length data
 	      vlib_buffer_advance (b0, (word) hdrlen);
 
@@ -2028,6 +2318,16 @@ VLIB_NODE_FN (srv6_end_m_gtp6_d_di) (vlib_main_t * vm,
 
 	      hdr_len += sizeof (ip6_address_t) * 2;
 
+	      if (ie_size)
+		{
+		  tlv_siz =
+		    sizeof (ip6_sr_tlv_t) + sizeof (user_plane_sub_tlv_t) +
+		    ie_size;
+
+		  tlv_siz = (tlv_siz & ~0x07) + (tlv_siz & 0x07 ? 0x08 : 0x0);
+		  hdr_len += tlv_siz;
+		}
+
 	      // jump back to data[0] or pre_data if required
 	      vlib_buffer_advance (b0, -(word) hdr_len);
 
@@ -2109,6 +2409,24 @@ VLIB_NODE_FN (srv6_end_m_gtp6_d_di) (vlib_main_t * vm,
 		  ip6srv->sr.segments[0] = dst0;
 		}
 
+	      if (PREDICT_FALSE (ie_size))
+		{
+		  ip6_sr_tlv_t *tlv;
+		  user_plane_sub_tlv_t *sub_tlv;
+
+		  tlv =
+		    (ip6_sr_tlv_t *) ((u8 *) ip6srv + (hdr_len - tlv_siz));
+		  tlv->type = SRH_TLV_USER_PLANE_CONTAINER;
+		  tlv->length = tlv_siz - sizeof (ip6_sr_tlv_t);
+		  clib_memset (tlv->value, 0, tlv->length);
+
+		  sub_tlv = (user_plane_sub_tlv_t *) tlv->value;
+		  sub_tlv->length = ie_size;
+		  clib_memcpy_fast (sub_tlv->value, ie_buf, ie_size);
+
+		  ip6srv->sr.length += tlv_siz / 8;
+		}
+
 	      ip6srv->ip.payload_length =
 		clib_host_to_net_u16 (len0 + hdr_len - sizeof (ip6_header_t));
 	      ip6srv->ip.protocol = IP_PROTOCOL_IPV6_ROUTE;
@@ -2202,6 +2520,443 @@ VLIB_NODE_FN (srv6_end_m_gtp6_d_di) (vlib_main_t * vm,
   return frame->n_vectors;
 }
 
+// Function for SRv6 GTP6.DT function
+VLIB_NODE_FN (srv6_end_m_gtp6_dt) (vlib_main_t * vm,
+				   vlib_node_runtime_t * node,
+				   vlib_frame_t * frame)
+{
+  srv6_end_main_v6_dt_t *sm = &srv6_end_main_v6_dt;
+  ip6_sr_main_t *sm2 = &sr_main;
+  u32 n_left_from, next_index, *from, *to_next;
+  u32 thread_index = vm->thread_index;
+
+  u32 good_n = 0, bad_n = 0;
+
+  from = vlib_frame_vector_args (frame);
+  n_left_from = frame->n_vectors;
+  next_index = node->cached_next_index;
+
+  while (n_left_from > 0)
+    {
+      u32 n_left_to_next;
+
+      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
+
+      while (n_left_from > 0 && n_left_to_next > 0)
+	{
+	  u32 bi0;
+	  vlib_buffer_t *b0;
+	  srv6_end_gtp6_dt_param_t *ls_param;
+	  ip6_sr_localsid_t *ls0;
+
+	  ip6_gtpu_header_t *hdr0 = NULL;
+	  ip4_header_t *ip4 = NULL;
+	  ip6_header_t *ip6 = NULL;
+	  ip6_address_t src, dst;
+	  u32 teid;
+	  u32 hdrlen;
+	  u32 len0;
+
+	  u32 next0 = SRV6_END_M_GTP6_DT_NEXT_DROP;
+
+	  bi0 = from[0];
+	  to_next[0] = bi0;
+	  from += 1;
+	  to_next += 1;
+	  n_left_from -= 1;
+	  n_left_to_next -= 1;
+
+	  b0 = vlib_get_buffer (vm, bi0);
+	  ls0 =
+	    pool_elt_at_index (sm2->localsids,
+			       vnet_buffer (b0)->ip.adj_index[VLIB_TX]);
+
+	  ls_param = (srv6_end_gtp6_dt_param_t *) ls0->plugin_mem;
+
+	  hdr0 = vlib_buffer_get_current (b0);
+
+	  hdrlen = sizeof (ip6_gtpu_header_t);
+
+	  len0 = vlib_buffer_length_in_chain (vm, b0);
+
+	  if ((hdr0->ip6.protocol != IP_PROTOCOL_UDP)
+	      || (hdr0->udp.dst_port !=
+		  clib_host_to_net_u16 (SRV6_GTP_UDP_DST_PORT))
+	      || (len0 < sizeof (ip6_gtpu_header_t)))
+	    {
+	      next0 = SRV6_END_M_GTP6_DT_NEXT_DROP;
+
+	      bad_n++;
+	    }
+	  else
+	    {
+	      clib_memcpy_fast (src.as_u8, hdr0->ip6.src_address.as_u8,
+				sizeof (ip6_address_t));
+	      clib_memcpy_fast (dst.as_u8, hdr0->ip6.dst_address.as_u8,
+				sizeof (ip6_address_t));
+
+	      teid = hdr0->gtpu.teid;
+
+	      if (hdr0->gtpu.ver_flags & GTPU_EXTHDR_FLAG)
+		{
+		  hdrlen += sizeof (gtpu_exthdr_t);
+		  if (hdr0->gtpu.ext->nextexthdr == GTPU_EXTHDR_PDU_SESSION)
+		    {
+		      gtpu_pdu_session_t *sess;
+
+		      sess =
+			(gtpu_pdu_session_t *) (((char *) hdr0) +
+						sizeof (ip6_gtpu_header_t) +
+						sizeof (gtpu_exthdr_t));
+
+		      hdrlen += sizeof (gtpu_pdu_session_t);
+		      if (sess->u.val & GTPU_PDU_SESSION_P_BIT_MASK)
+			{
+			  hdrlen += sizeof (gtpu_paging_policy_t);
+			}
+		    }
+		}
+
+	      if (ls_param->type == SRV6_GTP6_DT4)
+		{
+		  vlib_buffer_advance (b0, (word) hdrlen);
+		  ip4 = vlib_buffer_get_current (b0);
+		  if ((ip4->ip_version_and_header_length & 0xf0) != 0x40)
+		    {
+		      next0 = SRV6_END_M_GTP6_DT_NEXT_DROP;
+		      bad_n++;
+		      goto DONE;
+		    }
+
+		  next0 = SRV6_END_M_GTP6_DT_NEXT_LOOKUP4;
+		  vnet_buffer (b0)->sw_if_index[VLIB_TX] =
+		    ls_param->fib4_index;
+		}
+	      else if (ls_param->type == SRV6_GTP6_DT6)
+		{
+		  ip6 = (ip6_header_t *) ((u8 *) hdr0 + hdrlen);
+		  if ((clib_net_to_host_u32
+		       (ip6->ip_version_traffic_class_and_flow_label) >> 28)
+		      != 6)
+		    {
+		      next0 = SRV6_END_M_GTP6_DT_NEXT_DROP;
+		      bad_n++;
+		      goto DONE;
+		    }
+
+		  next0 = SRV6_END_M_GTP6_DT_NEXT_LOOKUP6;
+		  if ((ip6->dst_address.as_u8[0] == 0xff)
+		      && ((ip6->dst_address.as_u8[1] & 0xc0) == 0x80))
+		    {
+		      vnet_buffer (b0)->sw_if_index[VLIB_TX] =
+			ls_param->local_fib_index;
+		    }
+		  else
+		    {
+		      vlib_buffer_advance (b0, (word) hdrlen);
+		      vnet_buffer (b0)->sw_if_index[VLIB_TX] =
+			ls_param->fib6_index;
+		    }
+		}
+	      else if (ls_param->type == SRV6_GTP6_DT46)
+		{
+		  ip6 = (ip6_header_t *) ((u8 *) hdr0 + hdrlen);
+		  if ((clib_net_to_host_u32
+		       (ip6->ip_version_traffic_class_and_flow_label) >> 28)
+		      == 6)
+		    {
+		      next0 = SRV6_END_M_GTP6_DT_NEXT_LOOKUP6;
+		      if ((ip6->dst_address.as_u8[0] == 0xff)
+			  && ((ip6->dst_address.as_u8[1] & 0xc0) == 0x80))
+			{
+			  vnet_buffer (b0)->sw_if_index[VLIB_TX] =
+			    ls_param->local_fib_index;
+			}
+		      else
+			{
+			  vlib_buffer_advance (b0, (word) hdrlen);
+			  vnet_buffer (b0)->sw_if_index[VLIB_TX] =
+			    ls_param->fib6_index;
+			}
+		    }
+		  else
+		    if ((clib_net_to_host_u32
+			 (ip6->ip_version_traffic_class_and_flow_label) >> 28)
+			== 4)
+		    {
+		      vlib_buffer_advance (b0, (word) hdrlen);
+		      next0 = SRV6_END_M_GTP6_DT_NEXT_LOOKUP4;
+		      vnet_buffer (b0)->sw_if_index[VLIB_TX] =
+			ls_param->fib4_index;
+		    }
+		  else
+		    {
+		      next0 = SRV6_END_M_GTP6_DT_NEXT_DROP;
+		      bad_n++;
+		      goto DONE;
+		    }
+		}
+	      else
+		{
+		  next0 = SRV6_END_M_GTP6_DT_NEXT_DROP;
+		  bad_n++;
+		  goto DONE;
+		}
+
+	      good_n++;
+
+	      if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE) &&
+		  PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
+		{
+		  srv6_end_rewrite_trace_t *tr =
+		    vlib_add_trace (vm, node, b0, sizeof (*tr));
+		  clib_memcpy (tr->src.as_u8, src.as_u8,
+			       sizeof (ip6_address_t));
+		  clib_memcpy (tr->dst.as_u8, dst.as_u8,
+			       sizeof (ip6_address_t));
+		  tr->teid = teid;
+		}
+	    }
+
+	DONE:
+	  vlib_increment_combined_counter
+	    (((next0 ==
+	       SRV6_END_M_GTP6_DT_NEXT_DROP) ? &(sm2->sr_ls_invalid_counters)
+	      : &(sm2->sr_ls_valid_counters)), thread_index,
+	     ls0 - sm2->localsids, 1, vlib_buffer_length_in_chain (vm, b0));
+
+	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
+					   n_left_to_next, bi0, next0);
+	}
+
+      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+    }
+
+  vlib_node_increment_counter (vm, sm->end_m_gtp6_dt_node_index,
+			       SRV6_END_ERROR_M_GTP6_DT_BAD_PACKETS, bad_n);
+
+  vlib_node_increment_counter (vm, sm->end_m_gtp6_dt_node_index,
+			       SRV6_END_ERROR_M_GTP6_DT_PACKETS, good_n);
+
+  return frame->n_vectors;
+}
+
+// Function for SRv6 GTP4.DT function
+VLIB_NODE_FN (srv6_t_m_gtp4_dt) (vlib_main_t * vm,
+				 vlib_node_runtime_t * node,
+				 vlib_frame_t * frame)
+{
+  srv6_t_main_v4_dt_t *sm = &srv6_t_main_v4_dt;
+  ip6_sr_main_t *sm2 = &sr_main;
+  u32 n_left_from, next_index, *from, *to_next;
+
+  u32 good_n = 0, bad_n = 0;
+
+  from = vlib_frame_vector_args (frame);
+  n_left_from = frame->n_vectors;
+  next_index = node->cached_next_index;
+
+  while (n_left_from > 0)
+    {
+      u32 n_left_to_next;
+
+      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
+
+      while (n_left_from > 0 && n_left_to_next > 0)
+	{
+	  u32 bi0;
+	  vlib_buffer_t *b0;
+	  srv6_t_gtp4_dt_param_t *ls_param;
+	  ip6_sr_sl_t *ls0;
+
+	  ip4_gtpu_header_t *hdr0 = NULL;
+	  ip4_header_t *ip4 = NULL;
+	  ip6_header_t *ip6 = NULL;
+	  ip6_address_t src, dst;
+	  u32 teid;
+	  u32 hdrlen;
+	  u32 len0;
+
+	  u32 next0 = SRV6_T_M_GTP4_DT_NEXT_DROP;
+
+	  bi0 = from[0];
+	  to_next[0] = bi0;
+	  from += 1;
+	  to_next += 1;
+	  n_left_from -= 1;
+	  n_left_to_next -= 1;
+
+	  b0 = vlib_get_buffer (vm, bi0);
+	  ls0 =
+	    pool_elt_at_index (sm2->sid_lists,
+			       vnet_buffer (b0)->ip.adj_index[VLIB_TX]);
+
+	  ls_param = (srv6_t_gtp4_dt_param_t *) ls0->plugin_mem;
+
+	  hdr0 = vlib_buffer_get_current (b0);
+
+	  hdrlen = sizeof (ip4_gtpu_header_t);
+
+	  len0 = vlib_buffer_length_in_chain (vm, b0);
+
+	  if ((hdr0->ip4.protocol != IP_PROTOCOL_UDP)
+	      || (hdr0->udp.dst_port !=
+		  clib_host_to_net_u16 (SRV6_GTP_UDP_DST_PORT))
+	      || (len0 < sizeof (ip4_gtpu_header_t)))
+	    {
+	      next0 = SRV6_T_M_GTP4_DT_NEXT_DROP;
+
+	      bad_n++;
+	    }
+	  else
+	    {
+	      clib_memcpy_fast (src.as_u8, hdr0->ip4.src_address.as_u8,
+				sizeof (ip4_address_t));
+	      clib_memcpy_fast (dst.as_u8, hdr0->ip4.dst_address.as_u8,
+				sizeof (ip4_address_t));
+
+	      teid = hdr0->gtpu.teid;
+
+	      if (hdr0->gtpu.ver_flags & GTPU_EXTHDR_FLAG)
+		{
+		  hdrlen += sizeof (gtpu_exthdr_t);
+		  if (hdr0->gtpu.ext->nextexthdr == GTPU_EXTHDR_PDU_SESSION)
+		    {
+		      gtpu_pdu_session_t *sess;
+
+		      sess =
+			(gtpu_pdu_session_t *) (((char *) hdr0) +
+						sizeof (ip6_gtpu_header_t) +
+						sizeof (gtpu_exthdr_t));
+
+		      hdrlen += sizeof (gtpu_pdu_session_t);
+		      if (sess->u.val & GTPU_PDU_SESSION_P_BIT_MASK)
+			{
+			  hdrlen += sizeof (gtpu_paging_policy_t);
+			}
+		    }
+		}
+
+	      if (ls_param->type == SRV6_GTP4_DT4)
+		{
+		  vlib_buffer_advance (b0, (word) hdrlen);
+		  ip4 = vlib_buffer_get_current (b0);
+		  if ((ip4->ip_version_and_header_length & 0xf0) != 0x40)
+		    {
+		      next0 = SRV6_T_M_GTP4_DT_NEXT_DROP;
+		      bad_n++;
+		      goto DONE;
+		    }
+
+		  next0 = SRV6_T_M_GTP4_DT_NEXT_LOOKUP4;
+		  vnet_buffer (b0)->sw_if_index[VLIB_TX] =
+		    ls_param->fib4_index;
+		}
+	      else if (ls_param->type == SRV6_GTP4_DT6)
+		{
+		  ip6 = (ip6_header_t *) ((u8 *) hdr0 + hdrlen);
+		  if ((clib_net_to_host_u32
+		       (ip6->ip_version_traffic_class_and_flow_label) >> 28)
+		      != 6)
+		    {
+		      next0 = SRV6_T_M_GTP4_DT_NEXT_DROP;
+		      bad_n++;
+		      goto DONE;
+		    }
+
+		  next0 = SRV6_T_M_GTP4_DT_NEXT_LOOKUP6;
+		  if ((ip6->dst_address.as_u8[0] == 0xff)
+		      && ((ip6->dst_address.as_u8[1] & 0xc0) == 0x80))
+		    {
+		      next0 = SRV6_T_M_GTP4_DT_NEXT_LOOKUP4;
+		      vnet_buffer (b0)->sw_if_index[VLIB_TX] =
+			ls_param->local_fib_index;
+		    }
+		  else
+		    {
+		      vlib_buffer_advance (b0, (word) hdrlen);
+		      vnet_buffer (b0)->sw_if_index[VLIB_TX] =
+			ls_param->fib6_index;
+		    }
+		}
+	      else if (ls_param->type == SRV6_GTP4_DT46)
+		{
+		  ip6 = (ip6_header_t *) ((u8 *) hdr0 + hdrlen);
+		  if ((clib_net_to_host_u32
+		       (ip6->ip_version_traffic_class_and_flow_label) >> 28)
+		      == 6)
+		    {
+		      next0 = SRV6_T_M_GTP4_DT_NEXT_LOOKUP6;
+		      if ((ip6->dst_address.as_u8[0] == 0xff)
+			  && ((ip6->dst_address.as_u8[1] & 0xc0) == 0x80))
+			{
+			  next0 = SRV6_T_M_GTP4_DT_NEXT_LOOKUP4;
+			  vnet_buffer (b0)->sw_if_index[VLIB_TX] =
+			    ls_param->local_fib_index;
+			}
+		      else
+			{
+			  vlib_buffer_advance (b0, (word) hdrlen);
+			  vnet_buffer (b0)->sw_if_index[VLIB_TX] =
+			    ls_param->fib6_index;
+			}
+		    }
+		  else
+		    if ((clib_net_to_host_u32
+			 (ip6->ip_version_traffic_class_and_flow_label) >> 28)
+			== 4)
+		    {
+		      vlib_buffer_advance (b0, (word) hdrlen);
+		      next0 = SRV6_T_M_GTP4_DT_NEXT_LOOKUP4;
+		      vnet_buffer (b0)->sw_if_index[VLIB_TX] =
+			ls_param->fib4_index;
+		    }
+		  else
+		    {
+		      next0 = SRV6_T_M_GTP4_DT_NEXT_DROP;
+		      bad_n++;
+		      goto DONE;
+		    }
+		}
+	      else
+		{
+		  next0 = SRV6_T_M_GTP4_DT_NEXT_DROP;
+		  bad_n++;
+		  goto DONE;
+		}
+
+	      good_n++;
+
+	      if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE) &&
+		  PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
+		{
+		  srv6_end_rewrite_trace_t *tr =
+		    vlib_add_trace (vm, node, b0, sizeof (*tr));
+		  clib_memcpy (tr->src.as_u8, src.as_u8,
+			       sizeof (ip6_address_t));
+		  clib_memcpy (tr->dst.as_u8, dst.as_u8,
+			       sizeof (ip6_address_t));
+		  tr->teid = teid;
+		}
+	    }
+
+	DONE:
+	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
+					   n_left_to_next, bi0, next0);
+	}
+
+      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+    }
+
+  vlib_node_increment_counter (vm, sm->t_m_gtp4_dt_node_index,
+			       SRV6_T_ERROR_M_GTP4_DT_BAD_PACKETS, bad_n);
+
+  vlib_node_increment_counter (vm, sm->t_m_gtp4_dt_node_index,
+			       SRV6_T_ERROR_M_GTP4_DT_PACKETS, good_n);
+
+  return frame->n_vectors;
+}
+
 VLIB_REGISTER_NODE (srv6_end_m_gtp6_e) =
 {
   .name = "srv6-end-m-gtp6-e",.vector_size = sizeof (u32),.format_trace =
@@ -2210,8 +2965,8 @@ VLIB_REGISTER_NODE (srv6_end_m_gtp6_e) =
     srv6_end_error_v6_e_strings,.n_next_nodes =
     SRV6_END_M_GTP6_E_N_NEXT,.next_nodes =
   {
-  [SRV6_END_M_GTP6_E_NEXT_DROP] = "error-drop",
-      [SRV6_END_M_GTP6_E_NEXT_LOOKUP] = "ip6-lookup",}
+  [SRV6_END_M_GTP6_E_NEXT_DROP] =
+      "error-drop",[SRV6_END_M_GTP6_E_NEXT_LOOKUP] = "ip6-lookup",}
 ,};
 
 VLIB_REGISTER_NODE (srv6_end_m_gtp6_d) =
@@ -2222,8 +2977,8 @@ VLIB_REGISTER_NODE (srv6_end_m_gtp6_d) =
     srv6_end_error_v6_d_strings,.n_next_nodes =
     SRV6_END_M_GTP6_D_N_NEXT,.next_nodes =
   {
-  [SRV6_END_M_GTP6_D_NEXT_DROP] = "error-drop",
-      [SRV6_END_M_GTP6_D_NEXT_LOOKUP] = "ip6-lookup",}
+  [SRV6_END_M_GTP6_D_NEXT_DROP] =
+      "error-drop",[SRV6_END_M_GTP6_D_NEXT_LOOKUP] = "ip6-lookup",}
 ,};
 
 VLIB_REGISTER_NODE (srv6_end_m_gtp6_d_di) =
@@ -2238,6 +2993,34 @@ VLIB_REGISTER_NODE (srv6_end_m_gtp6_d_di) =
       [SRV6_END_M_GTP6_D_DI_NEXT_LOOKUP] = "ip6-lookup",}
 ,};
 
+VLIB_REGISTER_NODE (srv6_end_m_gtp6_dt) =
+{
+  .name = "srv6-end-m-gtp6-dt",.vector_size = sizeof (u32),.format_trace =
+    format_srv6_end_rewrite_trace6,.type = VLIB_NODE_TYPE_INTERNAL,.n_errors =
+    ARRAY_LEN (srv6_end_error_v6_dt_strings),.error_strings =
+    srv6_end_error_v6_dt_strings,.n_next_nodes =
+    SRV6_END_M_GTP6_DT_N_NEXT,.next_nodes =
+  {
+  [SRV6_END_M_GTP6_DT_NEXT_DROP] =
+      "error-drop",
+      [SRV6_END_M_GTP6_DT_NEXT_LOOKUP4]
+      = "ip4-lookup",[SRV6_END_M_GTP6_DT_NEXT_LOOKUP6] = "ip6-lookup",}
+,};
+
+VLIB_REGISTER_NODE (srv6_t_m_gtp4_dt) =
+{
+  .name = "srv6-t-m-gtp4-dt",.vector_size = sizeof (u32),.format_trace =
+    format_srv6_end_rewrite_trace6,.type = VLIB_NODE_TYPE_INTERNAL,.n_errors =
+    ARRAY_LEN (srv6_t_error_v4_dt_strings),.error_strings =
+    srv6_t_error_v4_dt_strings,.n_next_nodes =
+    SRV6_T_M_GTP4_DT_N_NEXT,.next_nodes =
+  {
+  [SRV6_T_M_GTP4_DT_NEXT_DROP] =
+      "error-drop",
+      [SRV6_T_M_GTP4_DT_NEXT_LOOKUP4] =
+      "ip4-lookup",[SRV6_T_M_GTP4_DT_NEXT_LOOKUP6] = "ip6-lookup",}
+,};
+
 /*
 * fd.io coding-style-patch-verification: ON
 *
diff --git a/src/plugins/srv6-mobile/test/test_srv6_end.py b/src/plugins/srv6-mobile/test/test_srv6_end.py
deleted file mode 100644
index 9eb62c9ce33..00000000000
--- a/src/plugins/srv6-mobile/test/test_srv6_end.py
+++ /dev/null
@@ -1,160 +0,0 @@
-#!/usr/bin/env python
-
-from framework import VppTestCase
-from ipaddress import IPv4Address
-from ipaddress import IPv6Address
-from scapy.contrib.gtp import *
-from scapy.all import *
-
-
-class TestSRv6EndMGTP4E(VppTestCase):
-    """ SRv6 End.M.GTP4.E (SRv6 -> GTP-U) """
-
-    @classmethod
-    def setUpClass(cls):
-        super(TestSRv6EndMGTP4E, cls).setUpClass()
-        try:
-            cls.create_pg_interfaces(range(2))
-            cls.pg_if_i = cls.pg_interfaces[0]
-            cls.pg_if_o = cls.pg_interfaces[1]
-
-            cls.pg_if_i.config_ip6()
-            cls.pg_if_o.config_ip4()
-
-            cls.ip4_dst = cls.pg_if_o.remote_ip4
-            # cls.ip4_src = cls.pg_if_o.local_ip4
-            cls.ip4_src = "192.168.192.10"
-
-            for pg_if in cls.pg_interfaces:
-                pg_if.admin_up()
-                pg_if.resolve_arp()
-
-        except Exception:
-            super(TestSRv6EndMGTP4E, cls).tearDownClass()
-            raise
-
-    def create_packets(self, inner):
-
-        ip4_dst = IPv4Address(str(self.ip4_dst))
-        # 32bit prefix + 32bit IPv4 DA + 8bit + 32bit TEID + 24bit
-        dst = b'\xaa' * 4 + ip4_dst.packed + \
-            b'\x11' + b'\xbb' * 4 + b'\x11' * 3
-        ip6_dst = IPv6Address(dst)
-
-        ip4_src = IPv4Address(str(self.ip4_src))
-        # 64bit prefix + 32bit IPv4 SA + 16 bit port + 16bit
-        src = b'\xcc' * 8 + ip4_src.packed + \
-            b'\xdd' * 2 + b'\x11' * 2
-        ip6_src = IPv6Address(src)
-
-        self.logger.info("ip4 dst: {}".format(ip4_dst))
-        self.logger.info("ip4 src: {}".format(ip4_src))
-        self.logger.info("ip6 dst (remote srgw): {}".format(ip6_dst))
-        self.logger.info("ip6 src (local  srgw): {}".format(ip6_src))
-
-        pkts = list()
-        for d, s in inner:
-            pkt = (Ether() /
-                   IPv6(dst=str(ip6_dst), src=str(ip6_src)) /
-                   IPv6ExtHdrSegmentRouting() /
-                   IPv6(dst=d, src=s) /
-                   UDP(sport=1000, dport=23))
-            self.logger.info(pkt.show2(dump=True))
-            pkts.append(pkt)
-
-        return pkts
-
-    def test_srv6_end(self):
-        """ test_srv6_end """
-        pkts = self.create_packets([("A::1", "B::1"), ("C::1", "D::1")])
-
-        self.vapi.cli(
-            "sr localsid address {} behavior end.m.gtp4.e v4src_position 64"
-            .format(pkts[0]['IPv6'].dst))
-        self.logger.info(self.vapi.cli("show sr localsids"))
-
-        self.vapi.cli("clear errors")
-
-        self.pg0.add_stream(pkts)
-        self.pg_enable_capture(self.pg_interfaces)
-        self.pg_start()
-
-        self.logger.info(self.vapi.cli("show errors"))
-        self.logger.info(self.vapi.cli("show int address"))
-
-        capture = self.pg1.get_capture(len(pkts))
-
-        for pkt in capture:
-            self.logger.info(pkt.show2(dump=True))
-            self.assertEqual(pkt[IP].dst, self.ip4_dst)
-            self.assertEqual(pkt[IP].src, self.ip4_src)
-            self.assertEqual(pkt[GTP_U_Header].teid, 0xbbbbbbbb)
-
-
-class TestSRv6TMTmap(VppTestCase):
-    """ SRv6 T.M.Tmap (GTP-U -> SRv6) """
-
-    @classmethod
-    def setUpClass(cls):
-        super(TestSRv6TMTmap, cls).setUpClass()
-        try:
-            cls.create_pg_interfaces(range(2))
-            cls.pg_if_i = cls.pg_interfaces[0]
-            cls.pg_if_o = cls.pg_interfaces[1]
-
-            cls.pg_if_i.config_ip4()
-            cls.pg_if_o.config_ip6()
-
-            for pg_if in cls.pg_interfaces:
-                pg_if.admin_up()
-                pg_if.resolve_arp()
-
-        except Exception:
-            super(TestSRv6TMTmap, cls).tearDownClass()
-            raise
-
-
-class TestSRv6EndMGTP6E(VppTestCase):
-    """ SRv6 End.M.GTP6.E """
-
-    @classmethod
-    def setUpClass(cls):
-        super(TestSRv6EndMGTP6E, cls).setUpClass()
-        try:
-            cls.create_pg_interfaces(range(2))
-            cls.pg_if_i = cls.pg_interfaces[0]
-            cls.pg_if_o = cls.pg_interfaces[1]
-
-            cls.pg_if_i.config_ip4()
-            cls.pg_if_o.config_ip6()
-
-            for pg_if in cls.pg_interfaces:
-                pg_if.admin_up()
-                pg_if.resolve_arp()
-
-        except Exception:
-            super(TestSRv6EndMGTP6E, cls).tearDownClass()
-            raise
-
-
-class TestSRv6EndMGTP6D(VppTestCase):
-    """ SRv6 End.M.GTP6.D """
-
-    @classmethod
-    def setUpClass(cls):
-        super(TestSRv6EndMGTP6D, cls).setUpClass()
-        try:
-            cls.create_pg_interfaces(range(2))
-            cls.pg_if_i = cls.pg_interfaces[0]
-            cls.pg_if_o = cls.pg_interfaces[1]
-
-            cls.pg_if_i.config_ip4()
-            cls.pg_if_o.config_ip6()
-
-            for pg_if in cls.pg_interfaces:
-                pg_if.admin_up()
-                pg_if.resolve_arp()
-
-        except Exception:
-            super(TestSRv6EndMGTP6D, cls).tearDownClass()
-            raise
diff --git a/src/plugins/srv6-mobile/test/test_srv6_mobile.py b/src/plugins/srv6-mobile/test/test_srv6_mobile.py
new file mode 100644
index 00000000000..ec94b8b9c03
--- /dev/null
+++ b/src/plugins/srv6-mobile/test/test_srv6_mobile.py
@@ -0,0 +1,340 @@
+#!/usr/bin/env python
+
+from framework import VppTestCase
+from ipaddress import IPv4Address
+from ipaddress import IPv6Address
+from scapy.contrib.gtp import *
+from scapy.all import *
+
+
+class TestSRv6EndMGTP4E(VppTestCase):
+    """ SRv6 End.M.GTP4.E (SRv6 -> GTP-U) """
+
+    @classmethod
+    def setUpClass(cls):
+        super(TestSRv6EndMGTP4E, cls).setUpClass()
+        try:
+            cls.create_pg_interfaces(range(2))
+            cls.pg_if_i = cls.pg_interfaces[0]
+            cls.pg_if_o = cls.pg_interfaces[1]
+
+            cls.pg_if_i.config_ip6()
+            cls.pg_if_o.config_ip4()
+
+            cls.ip4_dst = cls.pg_if_o.remote_ip4
+            # cls.ip4_src = cls.pg_if_o.local_ip4
+            cls.ip4_src = "192.168.192.10"
+
+            for pg_if in cls.pg_interfaces:
+                pg_if.admin_up()
+                pg_if.resolve_arp()
+
+        except Exception:
+            super(TestSRv6EndMGTP4E, cls).tearDownClass()
+            raise
+
+    def create_packets(self, inner):
+
+        ip4_dst = IPv4Address(str(self.ip4_dst))
+        # 32bit prefix + 32bit IPv4 DA + 8bit + 32bit TEID + 24bit
+        dst = b'\xaa' * 4 + ip4_dst.packed + \
+            b'\x11' + b'\xbb' * 4 + b'\x11' * 3
+        ip6_dst = IPv6Address(dst)
+
+        ip4_src = IPv4Address(str(self.ip4_src))
+        # 64bit prefix + 32bit IPv4 SA + 16 bit port + 16bit
+        src = b'\xcc' * 8 + ip4_src.packed + \
+            b'\xdd' * 2 + b'\x11' * 2
+        ip6_src = IPv6Address(src)
+
+        self.logger.info("ip4 dst: {}".format(ip4_dst))
+        self.logger.info("ip4 src: {}".format(ip4_src))
+        self.logger.info("ip6 dst (remote srgw): {}".format(ip6_dst))
+        self.logger.info("ip6 src (local  srgw): {}".format(ip6_src))
+
+        pkts = list()
+        for d, s in inner:
+            pkt = (Ether() /
+                   IPv6(dst=str(ip6_dst), src=str(ip6_src)) /
+                   IPv6ExtHdrSegmentRouting() /
+                   IPv6(dst=d, src=s) /
+                   UDP(sport=1000, dport=23))
+            self.logger.info(pkt.show2(dump=True))
+            pkts.append(pkt)
+
+        return pkts
+
+    def test_srv6_mobile(self):
+        """ test_srv6_mobile """
+        pkts = self.create_packets([("A::1", "B::1"), ("C::1", "D::1")])
+
+        self.vapi.cli(
+            "sr localsid address {} behavior end.m.gtp4.e v4src_position 64"
+            .format(pkts[0]['IPv6'].dst))
+        self.logger.info(self.vapi.cli("show sr localsids"))
+
+        self.vapi.cli("clear errors")
+
+        self.pg0.add_stream(pkts)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+
+        self.logger.info(self.vapi.cli("show errors"))
+        self.logger.info(self.vapi.cli("show int address"))
+
+        capture = self.pg1.get_capture(len(pkts))
+
+        for pkt in capture:
+            self.logger.info(pkt.show2(dump=True))
+            self.assertEqual(pkt[IP].dst, self.ip4_dst)
+            self.assertEqual(pkt[IP].src, self.ip4_src)
+            self.assertEqual(pkt[GTP_U_Header].teid, 0xbbbbbbbb)
+
+
+class TestSRv6TMGTP4D(VppTestCase):
+    """ SRv6 T.M.GTP4.D (GTP-U -> SRv6) """
+
+    @classmethod
+    def setUpClass(cls):
+        super(TestSRv6TMGTP4D, cls).setUpClass()
+        try:
+            cls.create_pg_interfaces(range(2))
+            cls.pg_if_i = cls.pg_interfaces[0]
+            cls.pg_if_o = cls.pg_interfaces[1]
+
+            cls.pg_if_i.config_ip4()
+            cls.pg_if_i.config_ip6()
+            cls.pg_if_o.config_ip4()
+            cls.pg_if_o.config_ip6()
+
+            cls.ip4_dst = "1.1.1.1"
+            cls.ip4_src = "2.2.2.2"
+
+            cls.ip6_dst = cls.pg_if_o.remote_ip6
+
+            for pg_if in cls.pg_interfaces:
+                pg_if.admin_up()
+                pg_if.resolve_arp()
+                pg_if.resolve_ndp(timeout=5)
+
+        except Exception:
+            super(TestSRv6TMGTP4D, cls).tearDownClass()
+            raise
+
+    def create_packets(self, inner):
+
+        ip4_dst = IPv4Address(str(self.ip4_dst))
+
+        ip4_src = IPv4Address(str(self.ip4_src))
+
+        self.logger.info("ip4 dst: {}".format(ip4_dst))
+        self.logger.info("ip4 src: {}".format(ip4_src))
+
+        pkts = list()
+        for d, s in inner:
+            pkt = (Ether() /
+                   IP(dst=str(ip4_dst), src=str(ip4_src)) /
+                   UDP(sport=2152, dport=2152) /
+                   GTP_U_Header(gtp_type="g_pdu", teid=200) /
+                   IPv6(dst=d, src=s) /
+                   UDP(sport=1000, dport=23))
+            self.logger.info(pkt.show2(dump=True))
+            pkts.append(pkt)
+
+        return pkts
+
+    def test_srv6_mobile(self):
+        """ test_srv6_mobile """
+        pkts = self.create_packets([("A::1", "B::1"), ("C::1", "D::1")])
+
+        self.vapi.cli("set sr encaps source addr A1::1")
+        self.vapi.cli("sr policy add bsid D4:: next D2:: next D3::")
+        self.vapi.cli(
+            "sr policy add bsid D5:: behavior t.m.gtp4.d"
+            "D4::/32 v6src_prefix C1::/64 nhtype ipv6")
+        self.vapi.cli("sr steer l3 {}/32 via bsid D5::".format(self.ip4_dst))
+        self.vapi.cli("ip route add D2::/32 via {}".format(self.ip6_dst))
+
+        self.logger.info(self.vapi.cli("show sr steer"))
+        self.logger.info(self.vapi.cli("show sr policies"))
+
+        self.vapi.cli("clear errors")
+
+        self.pg0.add_stream(pkts)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+
+        self.logger.info(self.vapi.cli("show errors"))
+        self.logger.info(self.vapi.cli("show int address"))
+
+        capture = self.pg1.get_capture(len(pkts))
+
+        for pkt in capture:
+            self.logger.info(pkt.show2(dump=True))
+            self.logger.info("GTP4.D Address={}".format(
+                str(pkt[IPv6ExtHdrSegmentRouting].addresses[0])))
+            self.assertEqual(
+                str(pkt[IPv6ExtHdrSegmentRouting].addresses[0]),
+                "d4:0:101:101::c800:0")
+
+
+class TestSRv6EndMGTP6E(VppTestCase):
+    """ SRv6 End.M.GTP6.E """
+
+    @classmethod
+    def setUpClass(cls):
+        super(TestSRv6EndMGTP6E, cls).setUpClass()
+        try:
+            cls.create_pg_interfaces(range(2))
+            cls.pg_if_i = cls.pg_interfaces[0]
+            cls.pg_if_o = cls.pg_interfaces[1]
+
+            cls.pg_if_i.config_ip6()
+            cls.pg_if_o.config_ip6()
+
+            cls.ip6_nhop = cls.pg_if_o.remote_ip6
+
+            for pg_if in cls.pg_interfaces:
+                pg_if.admin_up()
+                pg_if.resolve_ndp(timeout=5)
+
+        except Exception:
+            super(TestSRv6EndMGTP6E, cls).tearDownClass()
+            raise
+
+    def create_packets(self, inner):
+        # 64bit prefix + 32bit TEID + 8bit QFI + 24bit
+        dst = b'\xaa' * 8 + b'\x00' + \
+            b'\xbb' * 4 + b'\x00' * 3
+        ip6_dst = IPv6Address(dst)
+
+        self.ip6_dst = ip6_dst
+
+        src = b'\xcc' * 8 + \
+            b'\xdd' * 4 + b'\x11' * 4
+        ip6_src = IPv6Address(src)
+
+        self.ip6_src = ip6_src
+
+        pkts = list()
+        for d, s in inner:
+            pkt = (Ether() /
+                   IPv6(dst=str(ip6_dst),
+                        src=str(ip6_src)) /
+                   IPv6ExtHdrSegmentRouting(segleft=1,
+                                            lastentry=0,
+                                            tag=0,
+                                            addresses=["a1::1"]) /
+                   IPv6(dst=d, src=s) / UDP(sport=1000, dport=23))
+            self.logger.info(pkt.show2(dump=True))
+            pkts.append(pkt)
+
+        return pkts
+
+    def test_srv6_mobile(self):
+        """ test_srv6_mobile """
+        pkts = self.create_packets([("A::1", "B::1"), ("C::1", "D::1")])
+
+        self.vapi.cli(
+            "sr localsid prefix {}/64 behavior end.m.gtp6.e"
+            .format(pkts[0]['IPv6'].dst))
+        self.vapi.cli(
+            "ip route add a1::/64 via {}".format(self.ip6_nhop))
+        self.logger.info(self.vapi.cli("show sr localsids"))
+
+        self.vapi.cli("clear errors")
+
+        self.pg0.add_stream(pkts)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+
+        self.logger.info(self.vapi.cli("show errors"))
+        self.logger.info(self.vapi.cli("show int address"))
+
+        capture = self.pg1.get_capture(len(pkts))
+
+        for pkt in capture:
+            self.logger.info(pkt.show2(dump=True))
+            self.assertEqual(pkt[IPv6].dst, "a1::1")
+            self.assertEqual(pkt[IPv6].src, str(self.ip6_src))
+            self.assertEqual(pkt[GTP_U_Header].teid, 0xbbbbbbbb)
+
+
+class TestSRv6EndMGTP6D(VppTestCase):
+    """ SRv6 End.M.GTP6.D """
+
+    @classmethod
+    def setUpClass(cls):
+        super(TestSRv6EndMGTP6D, cls).setUpClass()
+        try:
+            cls.create_pg_interfaces(range(2))
+            cls.pg_if_i = cls.pg_interfaces[0]
+            cls.pg_if_o = cls.pg_interfaces[1]
+
+            cls.pg_if_i.config_ip6()
+            cls.pg_if_o.config_ip6()
+
+            cls.ip6_nhop = cls.pg_if_o.remote_ip6
+
+            cls.ip6_dst = "2001::1"
+            cls.ip6_src = "2002::1"
+
+            for pg_if in cls.pg_interfaces:
+                pg_if.admin_up()
+                pg_if.resolve_ndp(timeout=5)
+
+        except Exception:
+            super(TestSRv6EndMGTP6D, cls).tearDownClass()
+            raise
+
+    def create_packets(self, inner):
+
+        ip6_dst = IPv6Address(str(self.ip6_dst))
+
+        ip6_src = IPv6Address(str(self.ip6_src))
+
+        self.logger.info("ip6 dst: {}".format(ip6_dst))
+        self.logger.info("ip6 src: {}".format(ip6_src))
+
+        pkts = list()
+        for d, s in inner:
+            pkt = (Ether() /
+                   IPv6(dst=str(ip6_dst), src=str(ip6_src)) /
+                   UDP(sport=2152, dport=2152) /
+                   GTP_U_Header(gtp_type="g_pdu", teid=200) /
+                   IPv6(dst=d, src=s) /
+                   UDP(sport=1000, dport=23))
+            self.logger.info(pkt.show2(dump=True))
+            pkts.append(pkt)
+
+        return pkts
+
+    def test_srv6_mobile(self):
+        """ test_srv6_mobile """
+        pkts = self.create_packets([("A::1", "B::1"), ("C::1", "D::1")])
+
+        self.vapi.cli("set sr encaps source addr A1::1")
+        self.vapi.cli("sr policy add bsid D4:: next D2:: next D3::")
+        self.vapi.cli(
+            "sr localsid prefix 2001::/64 behavior end.m.gtp6.d D4::/64")
+        self.vapi.cli("ip route add D2::/64 via {}".format(self.ip6_nhop))
+
+        self.logger.info(self.vapi.cli("show sr policies"))
+
+        self.vapi.cli("clear errors")
+
+        self.pg0.add_stream(pkts)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+
+        self.logger.info(self.vapi.cli("show errors"))
+        self.logger.info(self.vapi.cli("show int address"))
+
+        capture = self.pg1.get_capture(len(pkts))
+
+        for pkt in capture:
+            self.logger.info(pkt.show2(dump=True))
+            self.logger.info("GTP6.D Address={}".format(
+                str(pkt[IPv6ExtHdrSegmentRouting].addresses[0])))
+            self.assertEqual(
+                str(pkt[IPv6ExtHdrSegmentRouting].addresses[0]), "d4::c800:0")
diff --git a/src/vnet/srv6/sr_packet.h b/src/vnet/srv6/sr_packet.h
index d2fb0898530..dda776b4037 100755
--- a/src/vnet/srv6/sr_packet.h
+++ b/src/vnet/srv6/sr_packet.h
@@ -149,6 +149,13 @@ typedef struct
   ip6_address_t segments[0];
 } __attribute__ ((packed)) ip6_sr_header_t;
 
+typedef struct
+{
+  u8 type;
+  u8 length;
+  u8 value[0];
+} __attribute__ ((packed)) ip6_sr_tlv_t;
+
 /*
 * fd.io coding-style-patch-verification: ON
 *