From c6e97a945ea813c7d9bae43377035ba4980b8a11 Mon Sep 17 00:00:00 2001
From: Thomas Bachman <tbachman@yahoo.com>
Date: Thu, 8 Mar 2018 17:24:21 +0000
Subject: [PATCH] Add DHCP agent MAC address to gbp_details

The MAC address and IP list of the ports belonging to the
DHCP agent responsible for a given port are added to the
get_gbp_details RPC. This allows the agent to support proxying
ARPs for the DHCP agent's IP, using the appropriate MAC.

Change-Id: Ia125dbc3207731a753d4fa1cafa50d4a4a928b89
---
 .../drivers/cisco/apic/aim_mapping.py         | 34 ++++++++++++-------
 1 file changed, 22 insertions(+), 12 deletions(-)

diff --git a/gbpservice/neutron/services/grouppolicy/drivers/cisco/apic/aim_mapping.py b/gbpservice/neutron/services/grouppolicy/drivers/cisco/apic/aim_mapping.py
index f94d12141..bef8b8e43 100644
--- a/gbpservice/neutron/services/grouppolicy/drivers/cisco/apic/aim_mapping.py
+++ b/gbpservice/neutron/services/grouppolicy/drivers/cisco/apic/aim_mapping.py
@@ -1959,18 +1959,21 @@ class AIMMappingDriver(nrd.CommonNeutronBase, aim_rpc.AIMMappingRPCMixin):
             plugin_context,
             filters={'id': [ip['subnet_id'] for ip in port['fixed_ips']]})
         for subnet in subnets:
-            dhcp_ips = set()
-            for port in self._get_ports(
+            dhcp_ports = {}
+            subnet_dhcp_ips = set()
+            for dhcp_port in self._get_ports(
                     plugin_context,
                     filters={
                         'network_id': [subnet['network_id']],
                         'device_owner': [n_constants.DEVICE_OWNER_DHCP]}):
-                dhcp_ips |= set([x['ip_address'] for x in port['fixed_ips']
-                                 if x['subnet_id'] == subnet['id']])
-            dhcp_ips = list(dhcp_ips)
+                dhcp_ips = set([x['ip_address'] for x in dhcp_port['fixed_ips']
+                                if x['subnet_id'] == subnet['id']])
+                dhcp_ports.setdefault(dhcp_port['mac_address'], list(dhcp_ips))
+                subnet_dhcp_ips |= dhcp_ips
+            subnet_dhcp_ips = list(subnet_dhcp_ips)
             if not subnet['dns_nameservers']:
                 # Use DHCP namespace port IP
-                subnet['dns_nameservers'] = dhcp_ips
+                subnet['dns_nameservers'] = subnet_dhcp_ips
             # Set Default & Metadata routes if needed
             default_route = metadata_route = {}
             if subnet['ip_version'] == 4:
@@ -1996,12 +1999,19 @@ class AIMMappingDriver(nrd.CommonNeutronBase, aim_rpc.AIMMappingRPCMixin):
                              'nexthop': subnet['gateway_ip']})
                     optimized = self._is_metadata_optimized(plugin_context,
                                                             port)
-                    if not metadata_route and dhcp_ips and (not optimized or
-                            (optimized and not default_route)):
-                        subnet['host_routes'].append(
-                            {'destination': dhcp.METADATA_DEFAULT_CIDR,
-                             'nexthop': dhcp_ips[0]})
-            subnet['dhcp_server_ips'] = dhcp_ips
+                    # REVISIT: We need to decide if we should provide
+                    # host-routes for all of the DHCP agents. For now
+                    # use the first DHCP agent in our list for the
+                    # metadata host-route next-hop IPs
+                    if not metadata_route and dhcp_ports and (
+                        not optimized or (optimized and not default_route)):
+                        for ip in dhcp_ports[dhcp_ports.keys()[0]]:
+                            subnet['host_routes'].append(
+                                {'destination': dhcp.METADATA_DEFAULT_CIDR,
+                                 'nexthop': ip})
+            subnet['dhcp_server_ips'] = subnet_dhcp_ips
+            if dhcp_ports:
+                subnet['dhcp_server_ports'] = dhcp_ports
         return subnets
 
     def _send_port_update_notification(self, plugin_context, port):