acl-plugin: add whitelisted ethertype mode (VPP-1163)

Currently, ACL plugin largely does not care about the
ethertypes other than 0x0800 (IPv4) and 0x86dd (IPv6),
the only exception being 0x0806 (ARP), which is
dealt with by the MACIP ACLs.

The other ethertypes in L2 mode are just let through.

This adds a new API message acl_interface_set_etype_whitelist,
which allows to flip the mode of a given interface
into "ethertype whitelist mode": the caller of this message
must supply the two lists (inbound and outbound) of the ethertypes
that are to be permitted, the rest of the ethertypes are
dropped.

The whitelisting for a given interface and direction takes
effect only when a policy ACL is also applied.

This operates on the same classifier node as the one used for
dispatching the policy ACL, thus, if one wishes for most of the
reasonable IPv4 deployments to continue to operate within
the whitelist mode, they must permit ARP ethertype (0x0806)

The empty list for a given direction resets the processing
to allow the unknown ethertypes. So, if one wants to just
permit the IPv4 and IPv6 and nothing else, one can add
their ethertypes to the whitelist.

Add the "show acl-plugin interface" corresponding outputs
about the whitelists, vat command, and unittests.

Change-Id: I4659978c801f36d554b6615e56e424b77876662c
Signed-off-by: Andrew Yourtchenko <ayourtch@gmail.com>

2 files changed, 103 insertions, 7 deletions

diff --git a/test/test_acl_plugin.py b/test/test_acl_plugin.py
index 361ced14c21..5fcf09c5ee7 100644
--- a/test/test_acl_plugin.py
+++ b/test/test_acl_plugin.py
@@ -247,6 +247,15 @@ class TestACLplugin(VppTestCase):
                                                  acls=[reply.acl_index])
         return
 
+    def etype_whitelist(self, whitelist, n_input):
+        # Apply whitelists on all the interfaces
+        for i in self.pg_interfaces:
+            # checkstyle can't read long names. Help them.
+            fun = self.vapi.acl_interface_set_etype_whitelist
+            fun(sw_if_index=i.sw_if_index, n_input=n_input,
+                whitelist=whitelist)
+        return
+
     def create_upper_layer(self, packet_index, proto, ports=0):
         p = self.proto_map[proto]
         if p == 'UDP':
@@ -268,7 +277,8 @@ class TestACLplugin(VppTestCase):
         return ''
 
     def create_stream(self, src_if, packet_sizes, traffic_type=0, ipv6=0,
-                      proto=-1, ports=0, fragments=False, pkt_raw=True):
+                      proto=-1, ports=0, fragments=False,
+                      pkt_raw=True, etype=-1):
         """
         Create input packet stream for defined interface using hosts or
         deleted_hosts list.
@@ -300,6 +310,10 @@ class TestACLplugin(VppTestCase):
                         pkt_info.proto = proto
                     payload = self.info_to_payload(pkt_info)
                     p = Ether(dst=dst_host.mac, src=src_host.mac)
+                    if etype > 0:
+                        p = Ether(dst=dst_host.mac,
+                                  src=src_host.mac,
+                                  type=etype)
                     if pkt_info.ip:
                         p /= IPv6(dst=dst_host.ip6, src=src_host.ip6)
                         if fragments:
@@ -328,7 +342,8 @@ class TestACLplugin(VppTestCase):
                     pkts.append(p)
         return pkts
 
-    def verify_capture(self, pg_if, capture, traffic_type=0, ip_type=0):
+    def verify_capture(self, pg_if, capture,
+                       traffic_type=0, ip_type=0, etype=-1):
         """
         Verify captured input packet stream for defined interface.
 
@@ -341,6 +356,12 @@ class TestACLplugin(VppTestCase):
             last_info[i.sw_if_index] = None
         dst_sw_if_index = pg_if.sw_if_index
         for packet in capture:
+            if etype > 0:
+                if packet[Ether].type != etype:
+                    self.logger.error(ppp("Unexpected ethertype in packet:",
+                                          packet))
+                else:
+                    continue
             try:
                 # Raw data for ICMPv6 are stored in ICMPv6EchoRequest.data
                 if traffic_type == self.ICMP and ip_type == self.IPV6:
@@ -429,7 +450,7 @@ class TestACLplugin(VppTestCase):
         self.pg_start()
 
     def run_verify_test(self, traffic_type=0, ip_type=0, proto=-1, ports=0,
-                        frags=False, pkt_raw=True):
+                        frags=False, pkt_raw=True, etype=-1):
         # Test
         # Create incoming packet streams for packet-generator interfaces
         pkts_cnt = 0
@@ -437,7 +458,7 @@ class TestACLplugin(VppTestCase):
             if self.flows.__contains__(i):
                 pkts = self.create_stream(i, self.pg_if_packet_sizes,
                                           traffic_type, ip_type, proto, ports,
-                                          frags, pkt_raw)
+                                          frags, pkt_raw, etype)
                 if len(pkts) > 0:
                     i.add_stream(pkts)
                     pkts_cnt += len(pkts)
@@ -454,17 +475,18 @@ class TestACLplugin(VppTestCase):
                     capture = dst_if.get_capture(pkts_cnt)
                     self.logger.info("Verifying capture on interface %s" %
                                      dst_if.name)
-                    self.verify_capture(dst_if, capture, traffic_type, ip_type)
+                    self.verify_capture(dst_if, capture,
+                                        traffic_type, ip_type, etype)
 
     def run_verify_negat_test(self, traffic_type=0, ip_type=0, proto=-1,
-                              ports=0, frags=False):
+                              ports=0, frags=False, etype=-1):
         # Test
         self.reset_packet_infos()
         for i in self.pg_interfaces:
             if self.flows.__contains__(i):
                 pkts = self.create_stream(i, self.pg_if_packet_sizes,
                                           traffic_type, ip_type, proto, ports,
-                                          frags)
+                                          frags, True, etype)
                 if len(pkts) > 0:
                     i.add_stream(pkts)
 
@@ -1306,6 +1328,70 @@ class TestACLplugin(VppTestCase):
 
         self.logger.info("ACLP_TEST_FINISH_0113")
 
+    def test_0300_tcp_permit_v4_etype_aaaa(self):
+        """ permit TCPv4, send 0xAAAA etype
+        """
+        self.logger.info("ACLP_TEST_START_0300")
+
+        # Add an ACL
+        rules = []
+        rules.append(self.create_rule(self.IPV4, self.DENY, self.PORTS_RANGE_2,
+                     self.proto[self.IP][self.TCP]))
+        rules.append(self.create_rule(self.IPV4, self.PERMIT, self.PORTS_RANGE,
+                     self.proto[self.IP][self.TCP]))
+        # deny ip any any in the end
+        rules.append(self.create_rule(self.IPV4, self.DENY, self.PORTS_ALL, 0))
+
+        # Apply rules
+        self.apply_rules(rules, "permit ipv4 tcp")
+
+        # Traffic should still pass
+        self.run_verify_test(self.IP, self.IPV4, self.proto[self.IP][self.TCP])
+
+        # Traffic should still pass also for an odd ethertype
+        self.run_verify_test(self.IP, self.IPV4, self.proto[self.IP][self.TCP],
+                             0, False, True, 0xaaaa)
+
+        self.logger.info("ACLP_TEST_FINISH_0300")
+
+    def test_0305_tcp_permit_v4_etype_blacklist_aaaa(self):
+        """ permit TCPv4, whitelist 0x0BBB ethertype, send 0xAAAA, 0x0BBB
+        """
+        self.logger.info("ACLP_TEST_START_0305")
+
+        # Add an ACL
+        rules = []
+        rules.append(self.create_rule(self.IPV4, self.DENY, self.PORTS_RANGE_2,
+                     self.proto[self.IP][self.TCP]))
+        rules.append(self.create_rule(self.IPV4, self.PERMIT, self.PORTS_RANGE,
+                     self.proto[self.IP][self.TCP]))
+        # deny ip any any in the end
+        rules.append(self.create_rule(self.IPV4, self.DENY, self.PORTS_ALL, 0))
+
+        # Apply rules
+        self.apply_rules(rules, "permit ipv4 tcp")
+
+        # whitelist the 0xbbbb etype - so the 0xaaaa should be blocked
+        self.etype_whitelist([0xbbb], 1)
+
+        # The IPv4 traffic should still pass
+        self.run_verify_test(self.IP, self.IPV4, self.proto[self.IP][self.TCP])
+
+        # The oddball ethertype should be blocked
+        self.run_verify_negat_test(self.IP, self.IPV4,
+                                   self.proto[self.IP][self.TCP],
+                                   0, False, 0xaaaa)
+
+        # The whitelisted traffic, on the other hand, should pass
+        self.run_verify_test(self.IP, self.IPV4, self.proto[self.IP][self.TCP],
+                             0, False, True, 0x0bbb)
+
+        # remove the whitelist, the previously blocked 0xAAAA should pass now
+        self.etype_whitelist([], 0)
+        self.run_verify_test(self.IP, self.IPV4, self.proto[self.IP][self.TCP],
+                             0, False, True, 0xaaaa)
+
+        self.logger.info("ACLP_TEST_FINISH_0305")
 
 if __name__ == '__main__':
     unittest.main(testRunner=VppTestRunner)
diff --git a/test/vpp_papi_provider.py b/test/vpp_papi_provider.py
index 0e56af1ca9e..a10b777a13a 100644
--- a/test/vpp_papi_provider.py
+++ b/test/vpp_papi_provider.py
@@ -2680,6 +2680,16 @@ class VppPapiProvider(object):
                          'acls': acls},
                         expected_retval=expected_retval)
 
+    def acl_interface_set_etype_whitelist(self, sw_if_index,
+                                          n_input, whitelist,
+                                          expected_retval=0):
+        return self.api(self.papi.acl_interface_set_etype_whitelist,
+                        {'sw_if_index': sw_if_index,
+                         'count': len(whitelist),
+                         'n_input': n_input,
+                         'whitelist': whitelist},
+                        expected_retval=expected_retval)
+
     def acl_interface_add_del(self,
                               sw_if_index,
                               acl_index,