cnat: Destination based NAT

Type: feature

Signed-off-by: Neale Ranns <nranns@cisco.com>
Change-Id: I64a99a4fbc674212944247793fd5c1fb701408cb

1 files changed, 596 insertions, 0 deletions

diff --git a/src/plugins/cnat/test/test_cnat.py b/src/plugins/cnat/test/test_cnat.py
new file mode 100644
index 00000000000..18e3baadbed
--- /dev/null
+++ b/src/plugins/cnat/test/test_cnat.py
@@ -0,0 +1,596 @@
+#!/usr/bin/env python3
+
+import unittest
+
+from framework import VppTestCase, VppTestRunner
+from vpp_ip import DpoProto
+
+from scapy.packet import Raw
+from scapy.layers.l2 import Ether
+from scapy.layers.inet import IP, UDP, TCP
+from scapy.layers.inet6 import IPv6
+
+from ipaddress import ip_address, ip_network, \
+    IPv4Address, IPv6Address, IPv4Network, IPv6Network
+
+from vpp_object import VppObject
+from vpp_papi import VppEnum
+
+N_PKTS = 15
+
+
+def find_cnat_translation(test, id):
+    ts = test.vapi.cnat_translation_dump()
+    for t in ts:
+        if id == t.translation.id:
+            return True
+    return False
+
+
+class Ep(object):
+    """ CNat endpoint """
+
+    def __init__(self, ip, port, l4p=TCP):
+        self.ip = ip
+        self.port = port
+        self.l4p = l4p
+
+    def encode(self):
+        return {'addr': self.ip,
+                'port': self.port}
+
+    def __str__(self):
+        return ("%s:%d" % (self.ip, self.port))
+
+
+class EpTuple(object):
+    """ CNat endpoint """
+
+    def __init__(self, src, dst):
+        self.src = src
+        self.dst = dst
+
+    def encode(self):
+        return {'src_ep': self.src.encode(),
+                'dst_ep': self.dst.encode()}
+
+    def __str__(self):
+        return ("%s->%s" % (self.src, self.dst))
+
+
+class VppCNatTranslation(VppObject):
+
+    def __init__(self, test, iproto, vip, paths):
+        self._test = test
+        self.vip = vip
+        self.iproto = iproto
+        self.paths = paths
+        self.encoded_paths = []
+        for path in self.paths:
+            self.encoded_paths.append(path.encode())
+
+    @property
+    def vl4_proto(self):
+        ip_proto = VppEnum.vl_api_ip_proto_t
+        return {
+            UDP: ip_proto.IP_API_PROTO_UDP,
+            TCP: ip_proto.IP_API_PROTO_TCP,
+        }[self.iproto]
+
+    def delete(self):
+        r = self._test.vapi.cnat_translation_del(id=self.id)
+
+    def add_vpp_config(self):
+        r = self._test.vapi.cnat_translation_update(
+            {'vip': self.vip.encode(),
+             'ip_proto': self.vl4_proto,
+             'n_paths': len(self.paths),
+             'paths': self.encoded_paths})
+        self._test.registry.register(self, self._test.logger)
+        self.id = r.id
+
+    def modify_vpp_config(self, paths):
+        self.paths = paths
+        self.encoded_paths = []
+        for path in self.paths:
+            self.encoded_paths.append(path.encode())
+
+        r = self._test.vapi.cnat_translation_update(
+            {'vip': self.vip.encode(),
+             'ip_proto': self.vl4_proto,
+             'n_paths': len(self.paths),
+             'paths': self.encoded_paths})
+        self._test.registry.register(self, self._test.logger)
+
+    def remove_vpp_config(self):
+        self._test.vapi.cnat_translation_del(self.id)
+
+    def query_vpp_config(self):
+        return find_cnat_translation(self._test, self.id)
+
+    def object_id(self):
+        return ("cnat-translation-%s" % (self.vip))
+
+    def get_stats(self):
+        c = self._test.statistics.get_counter("/net/cnat-translation")
+        return c[0][self.id]
+
+
+class VppCNATSourceNat(VppObject):
+
+    def __init__(self, test, address, exclude_subnets=[]):
+        self._test = test
+        self.address = address
+        self.exclude_subnets = exclude_subnets
+
+    def add_vpp_config(self):
+        a = ip_address(self.address)
+        if 4 == a.version:
+            self._test.vapi.cnat_set_snat_addresses(snat_ip4=self.address)
+        else:
+            self._test.vapi.cnat_set_snat_addresses(snat_ip6=self.address)
+        for subnet in self.exclude_subnets:
+            self.cnat_exclude_subnet(subnet, True)
+
+    def cnat_exclude_subnet(self, exclude_subnet, isAdd=True):
+        add = 1 if isAdd else 0
+        self._test.vapi.cnat_add_del_snat_prefix(
+                prefix=exclude_subnet, is_add=add)
+
+    def query_vpp_config(self):
+        return False
+
+    def remove_vpp_config(self):
+        return False
+
+
+class TestCNatTranslation(VppTestCase):
+    """ CNat Translation """
+    extra_vpp_punt_config = ["cnat", "{",
+                             "session-max-age", "1",
+                             "tcp-max-age", "1", "}"]
+
+    @classmethod
+    def setUpClass(cls):
+        super(TestCNatTranslation, cls).setUpClass()
+
+    @classmethod
+    def tearDownClass(cls):
+        super(TestCNatTranslation, cls).tearDownClass()
+
+    def setUp(self):
+        super(TestCNatTranslation, self).setUp()
+
+        self.create_pg_interfaces(range(3))
+
+        for i in self.pg_interfaces:
+            i.admin_up()
+            i.config_ip4()
+            i.resolve_arp()
+            i.config_ip6()
+            i.resolve_ndp()
+
+    def tearDown(self):
+        for i in self.pg_interfaces:
+            i.unconfig_ip4()
+            i.unconfig_ip6()
+            i.admin_down()
+        super(TestCNatTranslation, self).tearDown()
+
+    def cnat_create_translation(self, vip, nbr, isV6=False):
+        ip_v = "ip6" if isV6 else "ip4"
+        dep = Ep(getattr(self.pg1.remote_hosts[nbr], ip_v), 4000 + nbr)
+        sep = Ep("::", 0) if isV6 else Ep("0.0.0.0", 0)
+        t1 = VppCNatTranslation(
+            self, vip.l4p, vip,
+            [EpTuple(sep, dep), EpTuple(sep, dep)])
+        t1.add_vpp_config()
+        return t1
+
+    def cnat_test_translation(self, t1, nbr, sports, isV6=False):
+        ip_v = "ip6" if isV6 else "ip4"
+        ip_class = IPv6 if isV6 else IP
+        vip = t1.vip
+
+        #
+        # Flows
+        #
+        for src in self.pg0.remote_hosts:
+            for sport in sports:
+                # from client to vip
+                p1 = (Ether(dst=self.pg0.local_mac,
+                            src=src.mac) /
+                      ip_class(src=getattr(src, ip_v), dst=vip.ip) /
+                      vip.l4p(sport=sport, dport=vip.port) /
+                      Raw())
+
+                self.vapi.cli("trace add pg-input 1")
+                rxs = self.send_and_expect(self.pg0,
+                                           p1 * N_PKTS,
+                                           self.pg1)
+
+                for rx in rxs:
+                    self.assert_packet_checksums_valid(rx)
+                    self.assertEqual(
+                        rx[ip_class].dst,
+                        getattr(self.pg1.remote_hosts[nbr], ip_v))
+                    self.assertEqual(rx[vip.l4p].dport, 4000 + nbr)
+                    self.assertEqual(
+                        rx[ip_class].src,
+                        getattr(src, ip_v))
+                    self.assertEqual(rx[vip.l4p].sport, sport)
+
+                # from vip to client
+                p1 = (Ether(dst=self.pg1.local_mac,
+                            src=self.pg1.remote_mac) /
+                      ip_class(src=getattr(
+                          self.pg1.remote_hosts[nbr],
+                          ip_v),
+                          dst=getattr(src, ip_v)) /
+                      vip.l4p(sport=4000 + nbr, dport=sport) /
+                      Raw())
+
+                rxs = self.send_and_expect(self.pg1,
+                                           p1 * N_PKTS,
+                                           self.pg0)
+
+                for rx in rxs:
+                    self.assert_packet_checksums_valid(rx)
+                    self.assertEqual(
+                        rx[ip_class].dst,
+                        getattr(src, ip_v))
+                    self.assertEqual(rx[vip.l4p].dport, sport)
+                    self.assertEqual(rx[ip_class].src, vip.ip)
+                    self.assertEqual(rx[vip.l4p].sport, vip.port)
+
+                #
+                # packets to the VIP that do not match a
+                # translation are dropped
+                #
+                p1 = (Ether(dst=self.pg0.local_mac,
+                            src=src.mac) /
+                      ip_class(src=getattr(src, ip_v), dst=vip.ip) /
+                      vip.l4p(sport=sport, dport=6666) /
+                      Raw())
+
+                self.send_and_assert_no_replies(self.pg0,
+                                                p1 * N_PKTS,
+                                                self.pg1)
+
+                #
+                # packets from the VIP that do not match a
+                # session are forwarded
+                #
+                p1 = (Ether(dst=self.pg1.local_mac,
+                            src=self.pg1.remote_mac) /
+                      ip_class(src=getattr(
+                          self.pg1.remote_hosts[nbr],
+                          ip_v),
+                          dst=getattr(src, ip_v)) /
+                      vip.l4p(sport=6666, dport=sport) /
+                      Raw())
+
+                rxs = self.send_and_expect(self.pg1,
+                                           p1 * N_PKTS,
+                                           self.pg0)
+
+        self.assertEqual(t1.get_stats()['packets'],
+                         N_PKTS *
+                         len(sports) *
+                         len(self.pg0.remote_hosts))
+
+    def cnat_test_translation_update(self, t1, sports, isV6=False):
+        ip_v = "ip6" if isV6 else "ip4"
+        ip_class = IPv6 if isV6 else IP
+        vip = t1.vip
+
+        #
+        # modify the translation to use a different backend
+        #
+        dep = Ep(getattr(self.pg2, 'remote_' + ip_v), 5000)
+        sep = Ep("::", 0) if isV6 else Ep("0.0.0.0", 0)
+        t1.modify_vpp_config([EpTuple(sep, dep)])
+
+        #
+        # existing flows follow the old path
+        #
+        for src in self.pg0.remote_hosts:
+            for sport in sports:
+                # from client to vip
+                p1 = (Ether(dst=self.pg0.local_mac,
+                            src=src.mac) /
+                      ip_class(src=getattr(src, ip_v), dst=vip.ip) /
+                      vip.l4p(sport=sport, dport=vip.port) /
+                      Raw())
+
+                rxs = self.send_and_expect(self.pg0,
+                                           p1 * N_PKTS,
+                                           self.pg1)
+
+        #
+        # new flows go to the new backend
+        #
+        for src in self.pg0.remote_hosts:
+            p1 = (Ether(dst=self.pg0.local_mac,
+                        src=src.mac) /
+                  ip_class(src=getattr(src, ip_v), dst=vip.ip) /
+                  vip.l4p(sport=9999, dport=vip.port) /
+                  Raw())
+
+            rxs = self.send_and_expect(self.pg0,
+                                       p1 * N_PKTS,
+                                       self.pg2)
+
+    def cnat_translation(self, vips, isV6=False):
+        """ CNat Translation """
+
+        ip_class = IPv6 if isV6 else IP
+        ip_v = "ip6" if isV6 else "ip4"
+        sports = [1234, 1233]
+
+        #
+        # turn the scanner off whilst testing otherwise sessions
+        # will time out
+        #
+        self.vapi.cli("test cnat scanner off")
+
+        sessions = self.vapi.cnat_session_dump()
+
+        trs = []
+        for nbr, vip in enumerate(vips):
+            trs.append(self.cnat_create_translation(vip, nbr, isV6=isV6))
+
+        self.logger.info(self.vapi.cli("sh cnat client"))
+        self.logger.info(self.vapi.cli("sh cnat translation"))
+
+        #
+        # translations
+        #
+        for nbr, vip in enumerate(vips):
+            self.cnat_test_translation(trs[nbr], nbr, sports, isV6=isV6)
+            self.cnat_test_translation_update(trs[nbr], sports, isV6=isV6)
+            if isV6:
+                self.logger.info(self.vapi.cli(
+                    "sh ip6 fib %s" % self.pg0.remote_ip6))
+            else:
+                self.logger.info(self.vapi.cli(
+                    "sh ip fib %s" % self.pg0.remote_ip4))
+            self.logger.info(self.vapi.cli("sh cnat session verbose"))
+
+        #
+        # turn the scanner back on and wait untill the sessions
+        # all disapper
+        #
+        self.vapi.cli("test cnat scanner on")
+
+        n_tries = 0
+        sessions = self.vapi.cnat_session_dump()
+        while (len(sessions) and n_tries < 100):
+            n_tries += 1
+            sessions = self.vapi.cnat_session_dump()
+            self.sleep(2)
+
+        self.assertTrue(n_tries < 100)
+
+        #
+        # load some flows again and purge
+        #
+        for vip in vips:
+            for src in self.pg0.remote_hosts:
+                for sport in sports:
+                    # from client to vip
+                    p1 = (Ether(dst=self.pg0.local_mac,
+                                src=src.mac) /
+                          ip_class(src=getattr(src, ip_v), dst=vip.ip) /
+                          vip.l4p(sport=sport, dport=vip.port) /
+                          Raw())
+                    self.send_and_expect(self.pg0,
+                                         p1 * N_PKTS,
+                                         self.pg2)
+
+        for tr in trs:
+            tr.delete()
+
+        self.assertTrue(self.vapi.cnat_session_dump())
+        self.vapi.cnat_session_purge()
+        self.assertFalse(self.vapi.cnat_session_dump())
+
+    def test_cnat6(self):
+        # """ CNat Translation ipv6 """
+        vips = [
+            Ep("30::1", 5555),
+            Ep("30::2", 5554),
+            Ep("30::2", 5553, UDP),
+        ]
+
+        self.pg0.generate_remote_hosts(len(vips))
+        self.pg0.configure_ipv6_neighbors()
+        self.pg1.generate_remote_hosts(len(vips))
+        self.pg1.configure_ipv6_neighbors()
+
+        self.cnat_translation(vips, isV6=True)
+
+    def test_cnat4(self):
+        # """ CNat Translation ipv4 """
+
+        vips = [
+            Ep("30.0.0.1", 5555),
+            Ep("30.0.0.2", 5554),
+            Ep("30.0.0.2", 5553, UDP),
+        ]
+
+        self.pg0.generate_remote_hosts(len(vips))
+        self.pg0.configure_ipv4_neighbors()
+        self.pg1.generate_remote_hosts(len(vips))
+        self.pg1.configure_ipv4_neighbors()
+
+        self.cnat_translation(vips)
+
+
+class TestCNatSourceNAT(VppTestCase):
+    """ CNat Source NAT """
+    extra_vpp_punt_config = ["cnat", "{",
+                             "session-max-age", "1",
+                             "tcp-max-age", "1", "}"]
+
+    @classmethod
+    def setUpClass(cls):
+        super(TestCNatSourceNAT, cls).setUpClass()
+
+    @classmethod
+    def tearDownClass(cls):
+        super(TestCNatSourceNAT, cls).tearDownClass()
+
+    def setUp(self):
+        super(TestCNatSourceNAT, self).setUp()
+
+        self.create_pg_interfaces(range(3))
+
+        for i in self.pg_interfaces:
+            i.admin_up()
+            i.config_ip4()
+            i.resolve_arp()
+            i.config_ip6()
+            i.resolve_ndp()
+
+    def tearDown(self):
+        for i in self.pg_interfaces:
+            i.unconfig_ip4()
+            i.unconfig_ip6()
+            i.admin_down()
+        super(TestCNatSourceNAT, self).tearDown()
+
+    def cnat_create_translation(self, srcNatAddr, interface, isV6=False):
+        t1 = VppCNATSourceNat(self, srcNatAddr)
+        t1.add_vpp_config()
+        cnat_arc_name = "ip6-unicast" if isV6 else "ip4-unicast"
+        cnat_feature_name = "ip6-cnat-snat" if isV6 else "ip4-cnat-snat"
+        self.vapi.feature_enable_disable(
+            enable=1,
+            arc_name=cnat_arc_name,
+            feature_name=cnat_feature_name,
+            sw_if_index=interface.sw_if_index)
+
+        return t1
+
+    def cnat_test_sourcenat(self, srcNatAddr, l4p=TCP, isV6=False):
+        ip_v = "ip6" if isV6 else "ip4"
+        ip_class = IPv6 if isV6 else IP
+        sports = [1234, 1235, 1236]
+        dports = [6661, 6662, 6663]
+
+        self.pg0.generate_remote_hosts(1)
+        self.pg0.configure_ipv4_neighbors()
+        self.pg0.configure_ipv6_neighbors()
+        self.pg1.generate_remote_hosts(len(sports))
+        self.pg1.configure_ipv4_neighbors()
+        self.pg1.configure_ipv6_neighbors()
+
+        self.vapi.cli("test cnat scanner on")
+        t1 = self.cnat_create_translation(srcNatAddr, self.pg0)
+
+        for nbr, remote_host in enumerate(self.pg1.remote_hosts):
+            # from pods to outside network
+            p1 = (
+                Ether(
+                    dst=self.pg0.local_mac,
+                    src=self.pg0.remote_hosts[0].mac) /
+                ip_class(
+                    src=getattr(self.pg0.remote_hosts[0], ip_v),
+                    dst=getattr(remote_host, ip_v)) /
+                l4p(sport=sports[nbr], dport=dports[nbr]) /
+                Raw())
+
+            rxs = self.send_and_expect(
+                                self.pg0,
+                                p1 * N_PKTS,
+                                self.pg1)
+            for rx in rxs:
+                self.assert_packet_checksums_valid(rx)
+                self.assertEqual(
+                    rx[ip_class].dst,
+                    getattr(remote_host, ip_v))
+                self.assertEqual(rx[l4p].dport, dports[nbr])
+                self.assertEqual(
+                    rx[ip_class].src,
+                    srcNatAddr)
+                sport = rx[l4p].sport
+
+            # from outside to pods
+            p2 = (
+                Ether(
+                    dst=self.pg1.local_mac,
+                    src=self.pg1.remote_hosts[nbr].mac) /
+                ip_class(src=getattr(remote_host, ip_v), dst=srcNatAddr) /
+                l4p(sport=dports[nbr], dport=sport) /
+                Raw())
+
+            rxs = self.send_and_expect(
+                                    self.pg1,
+                                    p2 * N_PKTS,
+                                    self.pg0)
+
+            for rx in rxs:
+                self.assert_packet_checksums_valid(rx)
+                self.assertEqual(
+                    rx[ip_class].dst,
+                    getattr(self.pg0.remote_hosts[0], ip_v))
+                self.assertEqual(rx[l4p].dport, sports[nbr])
+                self.assertEqual(rx[l4p].sport, dports[nbr])
+                self.assertEqual(
+                    rx[ip_class].src,
+                    getattr(remote_host, ip_v))
+
+            # add remote host to exclude list
+            subnet_mask = 100 if isV6 else 16
+            subnet = getattr(remote_host, ip_v) + "/" + str(subnet_mask)
+            exclude_subnet = ip_network(subnet, strict=False)
+
+            t1.cnat_exclude_subnet(exclude_subnet)
+            self.vapi.cnat_session_purge()
+
+            rxs = self.send_and_expect(
+                                self.pg0,
+                                p1 * N_PKTS,
+                                self.pg1)
+            for rx in rxs:
+                self.assert_packet_checksums_valid(rx)
+                self.assertEqual(
+                    rx[ip_class].dst,
+                    getattr(remote_host, ip_v))
+                self.assertEqual(rx[l4p].dport, dports[nbr])
+                self.assertEqual(
+                    rx[ip_class].src,
+                    getattr(self.pg0.remote_hosts[0], ip_v))
+
+            # remove remote host from exclude list
+            t1.cnat_exclude_subnet(exclude_subnet, isAdd=False)
+            self.vapi.cnat_session_purge()
+
+            rxs = self.send_and_expect(
+                    self.pg0,
+                    p1 * N_PKTS,
+                    self.pg1)
+
+            for rx in rxs:
+                self.assert_packet_checksums_valid(rx)
+                self.assertEqual(
+                    rx[ip_class].dst,
+                    getattr(remote_host, ip_v))
+                self.assertEqual(rx[l4p].dport, dports[nbr])
+                self.assertEqual(
+                    rx[ip_class].src,
+                    srcNatAddr)
+
+    # def test_cnat6_sourcenat(self):
+    #     # """ CNat Source Nat ipv6 """
+    #     self.cnat_test_sourcenat(self.pg2.remote_hosts[0].ip6, TCP, True)
+    #     self.cnat_test_sourcenat(self.pg2.remote_hosts[0].ip6, UDP, True)
+
+    def test_cnat4_sourcenat(self):
+        # """ CNat Source Nat ipv4 """
+        self.cnat_test_sourcenat(self.pg2.remote_hosts[0].ip4, TCP)
+        self.cnat_test_sourcenat(self.pg2.remote_hosts[0].ip4, UDP)
+
+if __name__ == '__main__':
+    unittest.main(testRunner=VppTestRunner)