DHCP Multiple Servers (VPP-602, VPP-605)

Multiple DHCP (4 and/or 6) servers can be added and removed through multiple calls to the 'set dhcp server' API.
All 4/6/ discover/solicit messages will then be replicated to all servers in the list. The expectation is that the servers/system is configured in such a way that this is viable.
If VSS information is providied for the clinet VRF which also has multiple servers configured, then the same VSS information is sent to each server. Likewise the source address of packets sent to from VPP to each server is the same.

Change-Id: I3287cb084c84b3f612b78bc69cfcb5b9c1f8934d
Signed-off-by: Neale Ranns <nranns@cisco.com>

1 files changed, 312 insertions, 44 deletions

diff --git a/test/test_dhcp.py b/test/test_dhcp.py
index a09c9bdb0b4..89667d3d1fc 100644
--- a/test/test_dhcp.py
+++ b/test/test_dhcp.py
@@ -2,8 +2,10 @@
 
 import unittest
 import socket
+import struct
 
 from framework import VppTestCase, VppTestRunner
+from vpp_neighbor import VppNeighbor
 
 from scapy.layers.l2 import Ether, getmacbyip
 from scapy.layers.inet import IP, UDP, ICMP
@@ -11,7 +13,7 @@ from scapy.layers.inet6 import IPv6, in6_getnsmac, in6_mactoifaceid
 from scapy.layers.dhcp import DHCP, BOOTP, DHCPTypes
 from scapy.layers.dhcp6 import DHCP6, DHCP6_Solicit, DHCP6_RelayForward, \
     DHCP6_RelayReply, DHCP6_Advertise, DHCP6OptRelayMsg, DHCP6OptIfaceId, \
-    DHCP6OptStatusCode, DHCP6OptVSS, DHCP6OptClientLinkLayerAddr
+    DHCP6OptStatusCode, DHCP6OptVSS, DHCP6OptClientLinkLayerAddr, DHCP6_Request
 from socket import AF_INET, AF_INET6
 from scapy.utils import inet_pton, inet_ntop
 from scapy.utils6 import in6_ptop
@@ -140,7 +142,7 @@ class TestDHCP(VppTestCase):
 
         return data
 
-    def verify_dhcp_offer(self, pkt, intf):
+    def verify_dhcp_offer(self, pkt, intf, fib_id=0, oui=0):
         ether = pkt[Ether]
         self.assertEqual(ether.dst, "ff:ff:ff:ff:ff:ff")
         self.assertEqual(ether.src, intf.local_mac)
@@ -162,15 +164,22 @@ class TestDHCP(VppTestCase):
                     is_offer = True
         self.assertTrue(is_offer)
 
-        data = self.validate_relay_options(pkt, intf, intf.local_ip4, 0, 0)
+        data = self.validate_relay_options(pkt, intf, intf.local_ip4,
+                                           fib_id, oui)
+
+    def verify_dhcp_discover(self, pkt, intf, src_intf=None, fib_id=0, oui=0,
+                             dst_mac=None, dst_ip=None):
+        if not dst_mac:
+            dst_mac = intf.remote_mac
+        if not dst_ip:
+            dst_ip = intf.remote_ip4
 
-    def verify_dhcp_discover(self, pkt, intf, src_intf=None, fib_id=0, oui=0):
         ether = pkt[Ether]
-        self.assertEqual(ether.dst, intf.remote_mac)
+        self.assertEqual(ether.dst, dst_mac)
         self.assertEqual(ether.src, intf.local_mac)
 
         ip = pkt[IP]
-        self.assertEqual(ip.dst, intf.remote_ip4)
+        self.assertEqual(ip.dst, dst_ip)
         self.assertEqual(ip.src, intf.local_ip4)
 
         udp = pkt[UDP]
@@ -195,13 +204,20 @@ class TestDHCP(VppTestCase):
     def verify_dhcp6_solicit(self, pkt, intf,
                              peer_ip, peer_mac,
                              fib_id=0,
-                             oui=0):
+                             oui=0,
+                             dst_mac=None,
+                             dst_ip=None):
+        if not dst_mac:
+            dst_mac = intf.remote_mac
+        if not dst_ip:
+            dst_ip = in6_ptop(intf.remote_ip6)
+
         ether = pkt[Ether]
-        self.assertEqual(ether.dst, intf.remote_mac)
+        self.assertEqual(ether.dst, dst_mac)
         self.assertEqual(ether.src, intf.local_mac)
 
         ip = pkt[IPv6]
-        self.assertEqual(in6_ptop(ip.dst), in6_ptop(intf.remote_ip6))
+        self.assertEqual(in6_ptop(ip.dst), dst_ip)
         self.assertEqual(in6_ptop(ip.src), in6_ptop(intf.local_ip6))
 
         udp = pkt[UDP]
@@ -453,6 +469,128 @@ class TestDHCP(VppTestCase):
                                   fib_id=1, oui=4)
 
         #
+        # Add a second DHCP server in VRF 1
+        #  expect clients messages to be relay to both configured servers
+        #
+        self.pg1.generate_remote_hosts(2)
+        server_addr2 = socket.inet_pton(AF_INET, self.pg1.remote_hosts[1].ip4)
+
+        self.vapi.dhcp_proxy_config(server_addr2,
+                                    src_addr,
+                                    rx_table_id=1,
+                                    server_table_id=1,
+                                    is_add=1)
+
+        #
+        # We'll need an ARP entry for the server to send it packets
+        #
+        arp_entry = VppNeighbor(self,
+                                self.pg1.sw_if_index,
+                                self.pg1.remote_hosts[1].mac,
+                                self.pg1.remote_hosts[1].ip4)
+        arp_entry.add_vpp_config()
+
+        #
+        # Send a discover from the client. expect two relayed messages
+        # The frist packet is sent to the second server
+        # We're not enforcing that here, it's just the way it is.
+        #
+        self.pg3.add_stream(pkts_disc_vrf1)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+
+        rx = self.pg1.get_capture(2)
+
+        option_82 = self.verify_dhcp_discover(
+            rx[0], self.pg1,
+            src_intf=self.pg3,
+            dst_mac=self.pg1.remote_hosts[1].mac,
+            dst_ip=self.pg1.remote_hosts[1].ip4,
+            fib_id=1, oui=4)
+        self.verify_dhcp_discover(rx[1], self.pg1, src_intf=self.pg3,
+                                  fib_id=1, oui=4)
+
+        #
+        # Send both packets back. Client gets both.
+        #
+        p1 = (Ether(dst=self.pg1.local_mac, src=self.pg1.remote_mac) /
+              IP(src=self.pg1.remote_ip4, dst=self.pg1.local_ip4) /
+              UDP(sport=DHCP4_SERVER_PORT, dport=DHCP4_SERVER_PORT) /
+              BOOTP(op=1) /
+              DHCP(options=[('message-type', 'offer'),
+                            ('relay_agent_Information', option_82),
+                            ('end')]))
+        p2 = (Ether(dst=self.pg1.local_mac, src=self.pg1.remote_mac) /
+              IP(src=self.pg1.remote_hosts[1].ip4, dst=self.pg1.local_ip4) /
+              UDP(sport=DHCP4_SERVER_PORT, dport=DHCP4_SERVER_PORT) /
+              BOOTP(op=1) /
+              DHCP(options=[('message-type', 'offer'),
+                            ('relay_agent_Information', option_82),
+                            ('end')]))
+        pkts = [p1, p2]
+
+        self.pg1.add_stream(pkts)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+
+        rx = self.pg3.get_capture(2)
+
+        self.verify_dhcp_offer(rx[0], self.pg3, fib_id=1, oui=4)
+        self.verify_dhcp_offer(rx[1], self.pg3, fib_id=1, oui=4)
+
+        #
+        # Ensure offers from non-servers are dropeed
+        #
+        p2 = (Ether(dst=self.pg1.local_mac, src=self.pg1.remote_mac) /
+              IP(src="8.8.8.8", dst=self.pg1.local_ip4) /
+              UDP(sport=DHCP4_SERVER_PORT, dport=DHCP4_SERVER_PORT) /
+              BOOTP(op=1) /
+              DHCP(options=[('message-type', 'offer'),
+                            ('relay_agent_Information', option_82),
+                            ('end')]))
+        self.send_and_assert_no_replies(self.pg1, p2,
+                                        "DHCP offer from non-server")
+
+        #
+        # Ensure only the discover is sent to multiple servers
+        #
+        p_req_vrf1 = (Ether(dst="ff:ff:ff:ff:ff:ff",
+                            src=self.pg3.remote_mac) /
+                      IP(src="0.0.0.0", dst="255.255.255.255") /
+                      UDP(sport=DHCP4_CLIENT_PORT,
+                          dport=DHCP4_SERVER_PORT) /
+                      BOOTP(op=1) /
+                      DHCP(options=[('message-type', 'request'),
+                                    ('end')]))
+
+        self.pg3.add_stream(p_req_vrf1)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+
+        rx = self.pg1.get_capture(1)
+
+        #
+        # Remove the second DHCP server
+        #
+        self.vapi.dhcp_proxy_config(server_addr2,
+                                    src_addr,
+                                    rx_table_id=1,
+                                    server_table_id=1,
+                                    is_add=0)
+
+        #
+        # Test we can still relay with the first
+        #
+        self.pg3.add_stream(pkts_disc_vrf1)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+
+        rx = self.pg1.get_capture(1)
+        rx = rx[0]
+        self.verify_dhcp_discover(rx, self.pg1, src_intf=self.pg3,
+                                  fib_id=1, oui=4)
+
+        #
         # Remove the VSS config
         #  relayed DHCP has default vlaues in the option.
         #
@@ -472,7 +610,7 @@ class TestDHCP(VppTestCase):
         self.vapi.dhcp_proxy_config(server_addr,
                                     src_addr,
                                     rx_table_id=1,
-                                    server_table_id=11,
+                                    server_table_id=1,
                                     is_add=0)
 
         self.send_and_assert_no_replies(self.pg2, pkts_disc_vrf0,
@@ -500,18 +638,16 @@ class TestDHCP(VppTestCase):
                           UDP(sport=DHCP6_SERVER_PORT,
                               dport=DHCP6_CLIENT_PORT) /
                           DHCP6_Solicit())
-        pkts_solicit_vrf0 = [p_solicit_vrf0]
         p_solicit_vrf1 = (Ether(dst=dmac, src=self.pg3.remote_mac) /
                           IPv6(src=dhcp_solicit_src_vrf1,
                                dst=dhcp_solicit_dst) /
                           UDP(sport=DHCP6_SERVER_PORT,
                               dport=DHCP6_CLIENT_PORT) /
                           DHCP6_Solicit())
-        pkts_solicit_vrf1 = [p_solicit_vrf1]
 
-        self.send_and_assert_no_replies(self.pg2, pkts_solicit_vrf0,
+        self.send_and_assert_no_replies(self.pg2, p_solicit_vrf0,
                                         "DHCP with no configuration")
-        self.send_and_assert_no_replies(self.pg3, pkts_solicit_vrf1,
+        self.send_and_assert_no_replies(self.pg3, p_solicit_vrf1,
                                         "DHCP with no configuration")
 
         #
@@ -525,9 +661,9 @@ class TestDHCP(VppTestCase):
                                     server_table_id=0,
                                     is_ipv6=1)
 
-        self.send_and_assert_no_replies(self.pg2, pkts_solicit_vrf0,
+        self.send_and_assert_no_replies(self.pg2, p_solicit_vrf0,
                                         "DHCP with no configuration")
-        self.send_and_assert_no_replies(self.pg3, pkts_solicit_vrf1,
+        self.send_and_assert_no_replies(self.pg3, p_solicit_vrf1,
                                         "DHCP with no configuration")
 
         #
@@ -538,13 +674,13 @@ class TestDHCP(VppTestCase):
         #
         # Now the DHCP requests are relayed to the server
         #
-        self.pg2.add_stream(pkts_solicit_vrf0)
+        self.pg2.add_stream(p_solicit_vrf0)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
 
         rx = self.pg0.get_capture(1)
-        rx = rx[0]
-        self.verify_dhcp6_solicit(rx, self.pg0,
+
+        self.verify_dhcp6_solicit(rx[0], self.pg0,
                                   dhcp_solicit_src_vrf0,
                                   self.pg2.remote_mac)
 
@@ -557,8 +693,7 @@ class TestDHCP(VppTestCase):
                       IPv6(dst=self.pg0.local_ip6, src=self.pg0.remote_ip6) /
                       UDP(sport=DHCP6_SERVER_PORT, dport=DHCP6_SERVER_PORT) /
                       DHCP6_Advertise())
-        pkts_adv_vrf0 = [p_adv_vrf0]
-        self.send_and_assert_no_replies(self.pg2, pkts_adv_vrf0,
+        self.send_and_assert_no_replies(self.pg2, p_adv_vrf0,
                                         "DHCP6 not a relay reply")
 
         # 2 - no relay message option
@@ -567,8 +702,7 @@ class TestDHCP(VppTestCase):
                       UDP(sport=DHCP6_SERVER_PORT, dport=DHCP6_SERVER_PORT) /
                       DHCP6_RelayReply() /
                       DHCP6_Advertise())
-        pkts_adv_vrf0 = [p_adv_vrf0]
-        self.send_and_assert_no_replies(self.pg2, pkts_adv_vrf0,
+        self.send_and_assert_no_replies(self.pg2, p_adv_vrf0,
                                         "DHCP not a relay message")
 
         # 3 - no circuit ID
@@ -578,8 +712,7 @@ class TestDHCP(VppTestCase):
                       DHCP6_RelayReply() /
                       DHCP6OptRelayMsg(optlen=0) /
                       DHCP6_Advertise())
-        pkts_adv_vrf0 = [p_adv_vrf0]
-        self.send_and_assert_no_replies(self.pg2, pkts_adv_vrf0,
+        self.send_and_assert_no_replies(self.pg2, p_adv_vrf0,
                                         "DHCP6 no circuit ID")
         # 4 - wrong circuit ID
         p_adv_vrf0 = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
@@ -589,8 +722,7 @@ class TestDHCP(VppTestCase):
                       DHCP6OptIfaceId(optlen=4, ifaceid='\x00\x00\x00\x05') /
                       DHCP6OptRelayMsg(optlen=0) /
                       DHCP6_Advertise())
-        pkts_adv_vrf0 = [p_adv_vrf0]
-        self.send_and_assert_no_replies(self.pg2, pkts_adv_vrf0,
+        self.send_and_assert_no_replies(self.pg2, p_adv_vrf0,
                                         "DHCP6 wrong circuit ID")
 
         #
@@ -611,8 +743,8 @@ class TestDHCP(VppTestCase):
         self.pg_start()
 
         rx = self.pg2.get_capture(1)
-        rx = rx[0]
-        self.verify_dhcp6_advert(rx, self.pg2, "::")
+
+        self.verify_dhcp6_advert(rx[0], self.pg2, "::")
 
         #
         # Send the relay response (the advertisement)
@@ -632,8 +764,8 @@ class TestDHCP(VppTestCase):
         self.pg_start()
 
         rx = self.pg2.get_capture(1)
-        rx = rx[0]
-        self.verify_dhcp6_advert(rx, self.pg2, dhcp_solicit_src_vrf0)
+
+        self.verify_dhcp6_advert(rx[0], self.pg2, dhcp_solicit_src_vrf0)
 
         #
         # Add all the config for VRF 1
@@ -648,13 +780,13 @@ class TestDHCP(VppTestCase):
         #
         # VRF 1 solicit
         #
-        self.pg3.add_stream(pkts_solicit_vrf1)
+        self.pg3.add_stream(p_solicit_vrf1)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
 
         rx = self.pg1.get_capture(1)
-        rx = rx[0]
-        self.verify_dhcp6_solicit(rx, self.pg1,
+
+        self.verify_dhcp6_solicit(rx[0], self.pg1,
                                   dhcp_solicit_src_vrf1,
                                   self.pg3.remote_mac)
 
@@ -676,21 +808,21 @@ class TestDHCP(VppTestCase):
         self.pg_start()
 
         rx = self.pg3.get_capture(1)
-        rx = rx[0]
-        self.verify_dhcp6_advert(rx, self.pg3, dhcp_solicit_src_vrf1)
+
+        self.verify_dhcp6_advert(rx[0], self.pg3, dhcp_solicit_src_vrf1)
 
         #
         # Add VSS config
         #  table=1, fib=id=1, oui=4
         self.vapi.dhcp_proxy_set_vss(1, 1, 4, is_ip6=1)
 
-        self.pg3.add_stream(pkts_solicit_vrf1)
+        self.pg3.add_stream(p_solicit_vrf1)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
 
         rx = self.pg1.get_capture(1)
-        rx = rx[0]
-        self.verify_dhcp6_solicit(rx, self.pg1,
+
+        self.verify_dhcp6_solicit(rx[0], self.pg1,
                                   dhcp_solicit_src_vrf1,
                                   self.pg3.remote_mac,
                                   fib_id=1,
@@ -702,27 +834,163 @@ class TestDHCP(VppTestCase):
         #
         self.vapi.dhcp_proxy_set_vss(1, 1, 4, is_ip6=1, is_add=0)
 
-        self.pg3.add_stream(pkts_solicit_vrf1)
+        self.pg3.add_stream(p_solicit_vrf1)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
 
         rx = self.pg1.get_capture(1)
-        rx = rx[0]
-        self.verify_dhcp6_solicit(rx, self.pg1,
+
+        self.verify_dhcp6_solicit(rx[0], self.pg1,
                                   dhcp_solicit_src_vrf1,
                                   self.pg3.remote_mac)
 
         #
-        # Cleanup
+        # Add a second DHCP server in VRF 1
+        #  expect clients messages to be relay to both configured servers
         #
-        self.vapi.dhcp_proxy_config(server_addr_vrf1,
+        self.pg1.generate_remote_hosts(2)
+        server_addr2 = socket.inet_pton(AF_INET6, self.pg1.remote_hosts[1].ip6)
+
+        self.vapi.dhcp_proxy_config(server_addr2,
+                                    src_addr_vrf1,
+                                    rx_table_id=1,
+                                    server_table_id=1,
+                                    is_ipv6=1)
+
+        #
+        # We'll need an ND entry for the server to send it packets
+        #
+        nd_entry = VppNeighbor(self,
+                               self.pg1.sw_if_index,
+                               self.pg1.remote_hosts[1].mac,
+                               self.pg1.remote_hosts[1].ip6,
+                               af=AF_INET6)
+        nd_entry.add_vpp_config()
+
+        #
+        # Send a discover from the client. expect two relayed messages
+        # The frist packet is sent to the second server
+        # We're not enforcing that here, it's just the way it is.
+        #
+        self.pg3.add_stream(p_solicit_vrf1)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+
+        rx = self.pg1.get_capture(2)
+
+        self.verify_dhcp6_solicit(rx[0], self.pg1,
+                                  dhcp_solicit_src_vrf1,
+                                  self.pg3.remote_mac)
+        self.verify_dhcp6_solicit(rx[1], self.pg1,
+                                  dhcp_solicit_src_vrf1,
+                                  self.pg3.remote_mac,
+                                  dst_mac=self.pg1.remote_hosts[1].mac,
+                                  dst_ip=self.pg1.remote_hosts[1].ip6)
+
+        #
+        # Send both packets back. Client gets both.
+        #
+        p1 = (Ether(dst=self.pg1.local_mac, src=self.pg1.remote_mac) /
+              IPv6(dst=self.pg1.local_ip6, src=self.pg1.remote_ip6) /
+              UDP(sport=DHCP6_SERVER_PORT, dport=DHCP6_SERVER_PORT) /
+              DHCP6_RelayReply(peeraddr=dhcp_solicit_src_vrf1) /
+              DHCP6OptIfaceId(optlen=4, ifaceid='\x00\x00\x00\x04') /
+              DHCP6OptRelayMsg(optlen=0) /
+              DHCP6_Advertise(trid=1) /
+              DHCP6OptStatusCode(statuscode=0))
+        p2 = (Ether(dst=self.pg1.local_mac, src=self.pg1.remote_hosts[1].mac) /
+              IPv6(dst=self.pg1.local_ip6, src=self.pg1._remote_hosts[1].ip6) /
+              UDP(sport=DHCP6_SERVER_PORT, dport=DHCP6_SERVER_PORT) /
+              DHCP6_RelayReply(peeraddr=dhcp_solicit_src_vrf1) /
+              DHCP6OptIfaceId(optlen=4, ifaceid='\x00\x00\x00\x04') /
+              DHCP6OptRelayMsg(optlen=0) /
+              DHCP6_Advertise(trid=1) /
+              DHCP6OptStatusCode(statuscode=0))
+
+        pkts = [p1, p2]
+
+        self.pg1.add_stream(pkts)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+
+        rx = self.pg3.get_capture(2)
+
+        self.verify_dhcp6_advert(rx[0], self.pg3, dhcp_solicit_src_vrf1)
+        self.verify_dhcp6_advert(rx[1], self.pg3, dhcp_solicit_src_vrf1)
+
+        #
+        # Ensure only solicit messages are duplicated
+        #
+        p_request_vrf1 = (Ether(dst=dmac, src=self.pg3.remote_mac) /
+                          IPv6(src=dhcp_solicit_src_vrf1,
+                               dst=dhcp_solicit_dst) /
+                          UDP(sport=DHCP6_SERVER_PORT,
+                              dport=DHCP6_CLIENT_PORT) /
+                          DHCP6_Request())
+
+        self.pg3.add_stream(p_request_vrf1)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+
+        rx = self.pg1.get_capture(1)
+
+        #
+        # Test we drop DHCP packets from addresses that are not configured as
+        # DHCP servers
+        #
+        p2 = (Ether(dst=self.pg1.local_mac, src=self.pg1.remote_hosts[1].mac) /
+              IPv6(dst=self.pg1.local_ip6, src="3001::1") /
+              UDP(sport=DHCP6_SERVER_PORT, dport=DHCP6_SERVER_PORT) /
+              DHCP6_RelayReply(peeraddr=dhcp_solicit_src_vrf1) /
+              DHCP6OptIfaceId(optlen=4, ifaceid='\x00\x00\x00\x04') /
+              DHCP6OptRelayMsg(optlen=0) /
+              DHCP6_Advertise(trid=1) /
+              DHCP6OptStatusCode(statuscode=0))
+        self.send_and_assert_no_replies(self.pg1, p2,
+                                        "DHCP6 not from server")
+
+        #
+        # Remove the second DHCP server
+        #
+        self.vapi.dhcp_proxy_config(server_addr2,
                                     src_addr_vrf1,
                                     rx_table_id=1,
                                     server_table_id=1,
                                     is_ipv6=1,
                                     is_add=0)
+
+        #
+        # Test we can still relay with the first
+        #
+        self.pg3.add_stream(p_solicit_vrf1)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+
+        rx = self.pg1.get_capture(1)
+
+        self.verify_dhcp6_solicit(rx[0], self.pg1,
+                                  dhcp_solicit_src_vrf1,
+                                  self.pg3.remote_mac)
+
+        #
+        # Cleanup
+        #
         self.vapi.dhcp_proxy_config(server_addr_vrf1,
                                     src_addr_vrf1,
+                                    rx_table_id=1,
+                                    server_table_id=1,
+                                    is_ipv6=1,
+                                    is_add=0)
+        self.vapi.dhcp_proxy_config(server_addr_vrf0,
+                                    src_addr_vrf0,
+                                    rx_table_id=0,
+                                    server_table_id=0,
+                                    is_ipv6=1,
+                                    is_add=0)
+
+        # duplicate delete
+        self.vapi.dhcp_proxy_config(server_addr_vrf0,
+                                    src_addr_vrf0,
                                     rx_table_id=0,
                                     server_table_id=0,
                                     is_ipv6=1,