dhcp: multiple additions

DHCP additions:
1) DHCPv4 will only relay a message back to the client, if the Option82 information is present. So make this the default.
2) It is no longer possible to select via the API to "insert circuit ID" - since this is now default
3) Remove the version 2 API since it's now the same as version 1.
4) Adding the VSS option is now conditional only on the presence of VSS config (not the 'insert' option in the set API)
5) DHCP proxy dump via API

Change-Id: Ia7271ba8c1d4dbf34a02c401d268ccfbb1b74f17
Signed-off-by: Neale Ranns <nranns@cisco.com>

1 files changed, 363 insertions, 313 deletions

diff --git a/src/vnet/dhcp/proxy_node.c b/src/vnet/dhcp/proxy_node.c
index 6a58fcdb..ab6819fe 100644
--- a/src/vnet/dhcp/proxy_node.c
+++ b/src/vnet/dhcp/proxy_node.c
@@ -18,6 +18,7 @@
 #include <vlib/vlib.h>
 #include <vnet/pg/pg.h>
 #include <vnet/dhcp/proxy.h>
+#include <vnet/dhcp/client.h>
 #include <vnet/fib/ip4_fib.h>
 
 static char * dhcp_proxy_error_strings[] = {
@@ -57,6 +58,8 @@ typedef struct {
 vlib_node_registration_t dhcp_proxy_to_server_node;
 vlib_node_registration_t dhcp_proxy_to_client_node;
 
+dhcp_proxy_main_t dhcp_proxy_main;
+
 u8 * format_dhcp_proxy_trace (u8 * s, va_list * args)
 {
   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
@@ -94,6 +97,42 @@ u8 * format_dhcp_proxy_header_with_length (u8 * s, va_list * args)
   return s;
 }
 
+static inline vss_info *
+dhcp_get_vss_info (dhcp_proxy_main_t *dm,
+                   u32 rx_fib_index)
+{
+  vss_info *v;
+
+  if (vec_len(dm->vss_index_by_rx_fib_index) <= rx_fib_index ||
+      dm->vss_index_by_rx_fib_index[rx_fib_index] == ~0)
+  {
+      v = NULL;
+  }
+  else
+  {
+      v = pool_elt_at_index (dm->vss,
+                             dm->vss_index_by_rx_fib_index[rx_fib_index]);
+  }
+
+  return (v);
+}
+
+static inline dhcp_server_t *
+dhcp_get_server (dhcp_proxy_main_t *dm,
+                 u32 rx_fib_index)
+{
+  dhcp_server_t *s = NULL;
+
+  if (vec_len(dm->dhcp_server_index_by_rx_fib_index) > rx_fib_index &&
+      dm->dhcp_server_index_by_rx_fib_index[rx_fib_index] != ~0)
+  {
+      s = pool_elt_at_index (dm->dhcp_servers,
+                             dm->dhcp_server_index_by_rx_fib_index[rx_fib_index]);
+  }
+
+  return (s);
+}
+
 static uword
 dhcp_proxy_to_server_input (vlib_main_t * vm,
                             vlib_node_runtime_t * node,
@@ -131,9 +170,12 @@ dhcp_proxy_to_server_input (vlib_main_t * vm,
           u32 sw_if_index = 0;
           u32 original_sw_if_index = 0;
           u8  *end = NULL;
-          u32 fib_index, server_index;
+          u32 fib_index;
           dhcp_server_t * server;
           u32 rx_sw_if_index;
+          dhcp_option_t *o;
+          u32 len = 0;
+          vlib_buffer_free_list_t *fl;
 
 	  bi0 = from[0];
 	  to_next[0] = bi0;
@@ -166,26 +208,16 @@ dhcp_proxy_to_server_input (vlib_main_t * vm,
           rx_sw_if_index = vnet_buffer(b0)->sw_if_index[VLIB_RX];
 
           fib_index = im->fib_index_by_sw_if_index [rx_sw_if_index];
-
-          if (fib_index < vec_len(dpm->dhcp_server_index_by_rx_fib_index))
-            server_index = dpm->dhcp_server_index_by_rx_fib_index[fib_index];
-          else
-            server_index = 0;
+          server = dhcp_get_server(dpm, fib_index);
           
-          if (PREDICT_FALSE (pool_is_free_index (dpm->dhcp_servers, 
-                                                 server_index)))
+          if (PREDICT_FALSE (NULL == server))
             {
-            no_server:
               error0 = DHCP_PROXY_ERROR_NO_SERVER;
               next0 = DHCP_PROXY_TO_SERVER_INPUT_NEXT_DROP;
               pkts_no_server++;
               goto do_trace;
             }
           
-          server = pool_elt_at_index (dpm->dhcp_servers, server_index);
-          if (server->valid == 0)
-            goto no_server;
-
           vlib_buffer_advance (b0, -(sizeof(*ip0)));
           ip0 = vlib_buffer_get_current (b0);
 
@@ -216,142 +248,131 @@ dhcp_proxy_to_server_input (vlib_main_t * vm,
           h0->gateway_ip_address.as_u32 = server->dhcp_src_address.as_u32;
           pkts_to_server++;
 
-          if (server->insert_option_82) 
-            {
-              u32 fib_index, fib_id, opt82_fib_id=0, opt82_oui=0;
-	      ip4_fib_t * fib;
-              dhcp_option_t *o = (dhcp_option_t *) h0->options;
-              u32 len = 0;
-              vlib_buffer_free_list_t *fl;
+          o = (dhcp_option_t *) h0->options;
               
-              fib_index = im->fib_index_by_sw_if_index 
-                [vnet_buffer(b0)->sw_if_index[VLIB_RX]];
-	      fib = ip4_fib_get (fib_index);
-	      fib_id = fib->table_id;
-
-              end = b0->data + b0->current_data + b0->current_length;
-              /* TLVs are not performance-friendly... */
-              while  (o->option != 0xFF /* end of options */ && (u8 *)o < end) 
-                  o = (dhcp_option_t *) (((uword) o) + (o->length + 2));
-
-              fl = vlib_buffer_get_free_list (vm, b0->free_list_index);
-              // start write at (option*)o, some packets have padding
-              if (((u8 *)o - (u8 *)b0->data + VPP_DHCP_OPTION82_SIZE) > fl->n_data_bytes)
-                {
-                  next0 = DHCP_PROXY_TO_SERVER_INPUT_NEXT_DROP;
-                  pkts_too_big++;
-                  goto do_trace;
-                }
+          fib_index = im->fib_index_by_sw_if_index 
+              [vnet_buffer(b0)->sw_if_index[VLIB_RX]];
+
+          end = b0->data + b0->current_data + b0->current_length;
+          /* TLVs are not performance-friendly... */
+          while  (o->option != 0xFF /* end of options */ && (u8 *)o < end) 
+              o = (dhcp_option_t *) (((uword) o) + (o->length + 2));
 
-              if ((o->option == 0xFF)  && ((u8 *)o <= end))
-                {  
-                  vnet_main_t *vnm = vnet_get_main();   
-                  u16 old_l0, new_l0;
-                  ip4_address_t _ia0, * ia0 = &_ia0;
-                  uword  *p_vss;
-                  vss_info *vss;
-                  vnet_sw_interface_t *swif;
-                  sw_if_index = 0;
-                  original_sw_if_index = 0;
+          fl = vlib_buffer_get_free_list (vm, b0->free_list_index);
+          // start write at (option*)o, some packets have padding
+          if (((u8 *)o - (u8 *)b0->data + VPP_DHCP_OPTION82_SIZE) > fl->n_data_bytes)
+          {
+              next0 = DHCP_PROXY_TO_SERVER_INPUT_NEXT_DROP;
+              pkts_too_big++;
+              goto do_trace;
+          }
+
+          if ((o->option == 0xFF)  && ((u8 *)o <= end))
+          {  
+              vnet_main_t *vnm = vnet_get_main();   
+              u16 old_l0, new_l0;
+              ip4_address_t _ia0, * ia0 = &_ia0;
+              vss_info *vss;
+              vnet_sw_interface_t *swif;
+              sw_if_index = 0;
+              original_sw_if_index = 0;
                   
-                  original_sw_if_index = sw_if_index = 
-                      vnet_buffer(b0)->sw_if_index[VLIB_RX];
-                  swif = vnet_get_sw_interface (vnm, sw_if_index);
-                  if (swif->flags & VNET_SW_INTERFACE_FLAG_UNNUMBERED)
-                      sw_if_index = swif->unnumbered_sw_if_index;
+              original_sw_if_index = sw_if_index = 
+                  vnet_buffer(b0)->sw_if_index[VLIB_RX];
+              swif = vnet_get_sw_interface (vnm, sw_if_index);
+              if (swif->flags & VNET_SW_INTERFACE_FLAG_UNNUMBERED)
+                  sw_if_index = swif->unnumbered_sw_if_index;
                   
-                  p_vss = hash_get (dpm->opt82vss_index_by_vrf_id,
-                                    fib_id);
-                  if (p_vss) 
-                    {
-                      vss = pool_elt_at_index (dpm->opt82vss, p_vss[0]);
-                      opt82_oui =  vss->vpn_id.oui;
-                      opt82_fib_id =  vss->vpn_id.fib_id;
-                    }
-                  /* 
-                   * Get the first ip4 address on the [client-side] 
-                   * RX interface, if not unnumbered. otherwise use
-                   * the loopback interface's ip address.
-                   */
-                  ia0 = ip4_interface_first_address(&ip4_main, sw_if_index, 0);
+              /* 
+               * Get the first ip4 address on the [client-side] 
+               * RX interface, if not unnumbered. otherwise use
+               * the loopback interface's ip address.
+               */
+              ia0 = ip4_interface_first_address(&ip4_main, sw_if_index, 0);
                   
-                  if (ia0 == 0)
-                    {
-                      error0 = DHCP_PROXY_ERROR_NO_INTERFACE_ADDRESS;
-                      next0 = DHCP_PROXY_TO_SERVER_INPUT_NEXT_DROP;
-                      pkts_no_interface_address++;
-                      goto do_trace;
-                    }
-
-                  /* Add option 82 */
-                  o->option = 82;   /* option 82 */
-                  o->length = 12;   /* 12 octets to follow */
-                  o->data[0] = 1;   /* suboption 1, circuit ID (=FIB id) */
-                  o->data[1] = 4;   /* length of suboption */
-                  o->data[2] = (original_sw_if_index >> 24) & 0xFF;
-                  o->data[3] = (original_sw_if_index >> 16) & 0xFF;
-                  o->data[4] = (original_sw_if_index >> 8)  & 0xFF;
-                  o->data[5] = (original_sw_if_index >> 0)  & 0xFF;
-		  o->data[6] = 5; /* suboption 5 (client RX intfc address) */
-		  o->data[7] = 4; /* length 4 */
-		  o->data[8] = ia0->as_u8[0];
-		  o->data[9] = ia0->as_u8[1];
-		  o->data[10] = ia0->as_u8[2];
-		  o->data[11] = ia0->as_u8[3];
-                  o->data[12] = 0xFF;
-                  if (opt82_oui !=0 || opt82_fib_id != 0)
-                    {
-                      o->data[12] = 151; /* vss suboption */
-                      if (255 == opt82_fib_id) {
-                          o->data[13] = 1;   /* length */
-                          o->data[14] = 255;   /* vss option type */
-                          o->data[15] = 152; /* vss control suboption */
-                          o->data[16] = 0;   /* length */
-                          /* and a new "end-of-options" option (0xff) */
-                          o->data[17] = 0xFF;
-                          o->length += 5;
-                      } else {
-                          o->data[13] = 8;   /* length */
-                          o->data[14] = 1;   /* vss option type */
-                          o->data[15] = (opt82_oui >> 16) & 0xff;
-                          o->data[16] = (opt82_oui >> 8) & 0xff;
-                          o->data[17] = (opt82_oui ) & 0xff;
-                          o->data[18] = (opt82_fib_id >> 24) & 0xff;
-                          o->data[19] = (opt82_fib_id >> 16) & 0xff;
-                          o->data[20] = (opt82_fib_id >> 8) & 0xff;
-                          o->data[21] = (opt82_fib_id) & 0xff;
-                          o->data[22] = 152; /* vss control suboption */
-                          o->data[23] = 0;   /* length */
+              if (ia0 == 0)
+              {
+                  error0 = DHCP_PROXY_ERROR_NO_INTERFACE_ADDRESS;
+                  next0 = DHCP_PROXY_TO_SERVER_INPUT_NEXT_DROP;
+                  pkts_no_interface_address++;
+                  goto do_trace;
+              }
+
+              /* Add option 82 */
+              o->option = 82;   /* option 82 */
+              o->length = 12;   /* 12 octets to follow */
+              o->data[0] = 1;   /* suboption 1, circuit ID (=FIB id) */
+              o->data[1] = 4;   /* length of suboption */
+              o->data[2] = (original_sw_if_index >> 24) & 0xFF;
+              o->data[3] = (original_sw_if_index >> 16) & 0xFF;
+              o->data[4] = (original_sw_if_index >> 8)  & 0xFF;
+              o->data[5] = (original_sw_if_index >> 0)  & 0xFF;
+              o->data[6] = 5; /* suboption 5 (client RX intfc address) */
+              o->data[7] = 4; /* length 4 */
+              o->data[8] = ia0->as_u8[0];
+              o->data[9] = ia0->as_u8[1];
+              o->data[10] = ia0->as_u8[2];
+              o->data[11] = ia0->as_u8[3];
+              o->data[12] = 0xFF;
+
+              vss = dhcp_get_vss_info (dpm, fib_index);
+              if (NULL != vss)
+              {
+                  u32 opt82_fib_id=0, opt82_oui=0;
+
+                  opt82_oui =  vss->vpn_id.oui;
+                  opt82_fib_id =  vss->vpn_id.fib_id;
+
+                  o->data[12] = 151; /* vss suboption */
+                  if (255 == opt82_fib_id) {
+                      o->data[13] = 1;   /* length */
+                      o->data[14] = 255;   /* vss option type */
+                      o->data[15] = 152; /* vss control suboption */
+                      o->data[16] = 0;   /* length */
+                      /* and a new "end-of-options" option (0xff) */
+                      o->data[17] = 0xFF;
+                      o->length += 5;
+                  } else {
+                      o->data[13] = 8;   /* length */
+                      o->data[14] = 1;   /* vss option type */
+                      o->data[15] = (opt82_oui >> 16) & 0xff;
+                      o->data[16] = (opt82_oui >> 8) & 0xff;
+                      o->data[17] = (opt82_oui ) & 0xff;
+                      o->data[18] = (opt82_fib_id >> 24) & 0xff;
+                      o->data[19] = (opt82_fib_id >> 16) & 0xff;
+                      o->data[20] = (opt82_fib_id >> 8) & 0xff;
+                      o->data[21] = (opt82_fib_id) & 0xff;
+                      o->data[22] = 152; /* vss control suboption */
+                      o->data[23] = 0;   /* length */
                           
-                          /* and a new "end-of-options" option (0xff) */
-                          o->data[24] = 0xFF;
-                          o->length += 12;
-                      }
+                      /* and a new "end-of-options" option (0xff) */
+                      o->data[24] = 0xFF;
+                      o->length += 12;
                   }
-
-                  len = o->length + 3;
-                  b0->current_length += len;
-                  /* Fix IP header length and checksum */
-                  old_l0 = ip0->length;
-                  new_l0 = clib_net_to_host_u16 (old_l0);
-                  new_l0 += len;
-                  new_l0 = clib_host_to_net_u16 (new_l0);
-                  ip0->length = new_l0;
-                  sum0 = ip0->checksum;
-                  sum0 = ip_csum_update (sum0, old_l0, new_l0, ip4_header_t,
-                                         length /* changed member */);
-                  ip0->checksum = ip_csum_fold (sum0);
-
-                  /* Fix UDP length */
-                  new_l0 = clib_net_to_host_u16 (u0->length);
-                  new_l0 += len;
-                  u0->length = clib_host_to_net_u16 (new_l0);
-                } else {
-                  vlib_node_increment_counter 
-                      (vm, dhcp_proxy_to_server_node.index,
-                       DHCP_PROXY_ERROR_OPTION_82_ERROR, 1);
-                }
-            }
+              }
+
+              len = o->length + 3;
+              b0->current_length += len;
+              /* Fix IP header length and checksum */
+              old_l0 = ip0->length;
+              new_l0 = clib_net_to_host_u16 (old_l0);
+              new_l0 += len;
+              new_l0 = clib_host_to_net_u16 (new_l0);
+              ip0->length = new_l0;
+              sum0 = ip0->checksum;
+              sum0 = ip_csum_update (sum0, old_l0, new_l0, ip4_header_t,
+                                     length /* changed member */);
+              ip0->checksum = ip_csum_fold (sum0);
+
+              /* Fix UDP length */
+              new_l0 = clib_net_to_host_u16 (u0->length);
+              new_l0 += len;
+              u0->length = clib_host_to_net_u16 (new_l0);
+          } else {
+              vlib_node_increment_counter 
+                  (vm, dhcp_proxy_to_server_node.index,
+                   DHCP_PROXY_ERROR_OPTION_82_ERROR, 1);
+          }
           
           next0 = DHCP_PROXY_TO_SERVER_INPUT_NEXT_LOOKUP;
 
@@ -451,11 +472,13 @@ dhcp_proxy_to_client_input (vlib_main_t * vm,
       vnet_sw_interface_t *si0;
       u32 error0 = (u32)~0;
       vnet_sw_interface_t *swif;
-      u32 server_index;
       u32 fib_index;
       dhcp_server_t * server;
       u32 original_sw_if_index = (u32) ~0;
-          
+      ip4_address_t relay_addr = {
+          .as_u32 = 0,
+      };
+
       bi0 = from[0];
       from += 1;
       n_left_from -= 1;
@@ -501,13 +524,21 @@ dhcp_proxy_to_client_input (vlib_main_t * vm,
                            and the sw_if_index */
                         if (sub->option == 1 && sub->length == 4)
                           {
-                            sw_if_index = (o->data[2] << 24)
-                                | (o->data[3] << 16)
-                                | (o->data[4] << 8)
-                                | (o->data[5]);
-                          } else if (sub->option == 151 &&
-                                     sub->length == 7 &&
-                                     sub->data[0] == 1)
+                            sw_if_index = ((sub->data[0] << 24) |
+                                           (sub->data[1] << 16) |
+                                           (sub->data[2] << 8)  |
+                                           (sub->data[3]));
+                          }
+                        else if (sub->option == 5 && sub->length == 4)
+                          {
+                              relay_addr.as_u8[0] = sub->data[0];
+                              relay_addr.as_u8[1] = sub->data[1];
+                              relay_addr.as_u8[2] = sub->data[2];
+                              relay_addr.as_u8[3] = sub->data[3];
+                          }
+                        else if (sub->option == 151 &&
+                                 sub->length == 7 &&
+                                 sub->data[0] == 1)
                             vss_exist = 1;
                         else if (sub->option == 152 && sub->length == 0)
                             vss_ctrl = 1;
@@ -539,34 +570,27 @@ dhcp_proxy_to_client_input (vlib_main_t * vm,
           goto do_trace;
         }
       
+      if (relay_addr.as_u32 == 0)
+        {
+          error0 = DHCP_PROXY_ERROR_BAD_OPTION_82_ADDR;
+          goto drop_packet;
+        }
 
       if (sw_if_index >= vec_len (im->fib_index_by_sw_if_index))
         {
-          error0 = DHCP_PROXY_ERROR_BAD_OPTION_82;
+          error0 = DHCP_PROXY_ERROR_BAD_OPTION_82_ITF;
           goto drop_packet;
         }
 
       fib_index = im->fib_index_by_sw_if_index [sw_if_index];
+      server = dhcp_get_server(dpm, fib_index);
 
-      if (fib_index < vec_len(dpm->dhcp_server_index_by_rx_fib_index))
-        server_index = dpm->dhcp_server_index_by_rx_fib_index[fib_index];
-      else
-        server_index = 0;
-
-      if (PREDICT_FALSE (pool_is_free_index (dpm->dhcp_servers, 
-                                             server_index)))
-        {
-          error0 = DHCP_PROXY_ERROR_BAD_OPTION_82;
-          goto drop_packet;
-        }
-      
-      server = pool_elt_at_index (dpm->dhcp_servers, server_index);
-      if (server->valid == 0)
+      if (PREDICT_FALSE (NULL == server))
         {
           error0 = DHCP_PROXY_ERROR_NO_SERVER;
           goto drop_packet;
         }
-
+      
       if (ip0->src_address.as_u32 != server->dhcp_server.as_u32)
         {             
           error0 = DHCP_PROXY_ERROR_BAD_SVR_FIB_OR_ADDRESS;
@@ -587,6 +611,12 @@ dhcp_proxy_to_client_input (vlib_main_t * vm,
           goto drop_packet;
         }
 
+      if (relay_addr.as_u32 != ia0->as_u32)
+        {             
+          error0 = DHCP_PROXY_ERROR_BAD_YIADDR;
+          goto drop_packet;
+        }
+
       u0->checksum = 0;
       u0->dst_port = clib_net_to_host_u16 (UDP_DST_PORT_dhcp_to_client);
       sum0 = ip0->checksum;
@@ -677,7 +707,7 @@ clib_error_t * dhcp_proxy_init (vlib_main_t * vm)
   error_drop_node = vlib_get_node_by_name (vm, (u8 *) "error-drop");
   dm->error_drop_node_index = error_drop_node->index;
 
-  dm->opt82vss_index_by_vrf_id = hash_create (0, sizeof (uword));
+  dm->vss_index_by_rx_fib_index = NULL;
 
   udp_register_dst_port (vm, UDP_DST_PORT_dhcp_to_client, 
                          dhcp_proxy_to_client_node.index, 1 /* is_ip4 */);
@@ -694,15 +724,17 @@ clib_error_t * dhcp_proxy_init (vlib_main_t * vm)
 
 VLIB_INIT_FUNCTION (dhcp_proxy_init);
 
-int dhcp_proxy_set_server_2 (ip4_address_t *addr, ip4_address_t *src_address,
-                             u32 rx_fib_id,
-                             u32 server_fib_id, 
-                             int insert_option_82, int is_del)
+int dhcp_proxy_set_server (ip4_address_t *addr,
+                           ip4_address_t *src_address,
+                           u32 rx_fib_id,
+                           u32 server_fib_id, 
+                           int is_del)
 {
   dhcp_proxy_main_t * dpm = &dhcp_proxy_main;
   dhcp_server_t * server = 0;
   u32 server_index = 0;
   u32 rx_fib_index = 0;
+
   const fib_prefix_t all_1s =
   {
       .fp_len = 32,
@@ -719,97 +751,68 @@ int dhcp_proxy_set_server_2 (ip4_address_t *addr, ip4_address_t *src_address,
   rx_fib_index = fib_table_find_or_create_and_lock(FIB_PROTOCOL_IP4,
                                                    rx_fib_id);
 
-  if (rx_fib_id == 0)
-    {
-      server = pool_elt_at_index (dpm->dhcp_servers, 0);
-      
-      if (is_del)
-        {
-          memset (server, 0, sizeof (*server));
-          fib_table_entry_special_remove(rx_fib_index,
-                                         &all_1s,
-                                         FIB_SOURCE_DHCP);
-         return 0;
-        }
-      if (!server->valid)
-          fib_table_entry_special_add(rx_fib_index,
-                                      &all_1s,
-                                      FIB_SOURCE_DHCP,
-                                      FIB_ENTRY_FLAG_LOCAL,
-                                      ADJ_INDEX_INVALID);
-
-      goto initialize_it;
-    }
-
   if (is_del)
     {
       if (rx_fib_index >= vec_len(dpm->dhcp_server_index_by_rx_fib_index))
         return VNET_API_ERROR_NO_SUCH_ENTRY;
       
       server_index = dpm->dhcp_server_index_by_rx_fib_index[rx_fib_index];
-      ASSERT(server_index > 0);
+
+      if (server_index == ~0)
+        return VNET_API_ERROR_NO_SUCH_ENTRY;
 
       /* Use the default server again.  */
-      dpm->dhcp_server_index_by_rx_fib_index[rx_fib_index] = 0;
+      dpm->dhcp_server_index_by_rx_fib_index[rx_fib_index] = ~0;
       server = pool_elt_at_index (dpm->dhcp_servers, server_index);
-      memset (server, 0, sizeof (*server));
-      pool_put (dpm->dhcp_servers, server);
 
       fib_table_entry_special_remove(rx_fib_index,
                                      &all_1s,
                                      FIB_SOURCE_DHCP);
+      fib_table_unlock (rx_fib_index,
+                        FIB_PROTOCOL_IP4);
+      fib_table_unlock (server->server_fib_index,
+                        FIB_PROTOCOL_IP4);
 
+      memset (server, 0, sizeof (*server));
+      pool_put (dpm->dhcp_servers, server);
       return 0;
     }
-
-  if (rx_fib_index < vec_len(dpm->dhcp_server_index_by_rx_fib_index))
-    {
-      server_index = dpm->dhcp_server_index_by_rx_fib_index[rx_fib_index];
-      if (server_index != 0)
-        {
-          server = pool_elt_at_index (dpm->dhcp_servers, server_index);
-          goto initialize_it;
-        }
-    }
-
-  pool_get (dpm->dhcp_servers, server);
-
-  fib_table_entry_special_add(rx_fib_index,
-                              &all_1s,
-                              FIB_SOURCE_DHCP,
-                              FIB_ENTRY_FLAG_LOCAL,
-                              ADJ_INDEX_INVALID);
-  
- initialize_it:
-
-
-  server->dhcp_server.as_u32 = addr->as_u32;
-  server->server_fib_index = 
-      fib_table_find_or_create_and_lock(FIB_PROTOCOL_IP4,
-	  				server_fib_id);
-  server->dhcp_src_address.as_u32 = src_address->as_u32;
-  server->insert_option_82 = insert_option_82;
-  server->valid = 1;
-  if (rx_fib_index)
-    {
-      vec_validate (dpm->dhcp_server_index_by_rx_fib_index, rx_fib_index);
+  else
+  {
+      vec_validate_init_empty(dpm->dhcp_server_index_by_rx_fib_index,
+                              rx_fib_index,
+                              ~0);
+
+      pool_get (dpm->dhcp_servers, server);
+
+      server->dhcp_server.as_u32 = addr->as_u32;
+      server->dhcp_src_address.as_u32 = src_address->as_u32;
+
+      fib_table_entry_special_add(rx_fib_index,
+                                  &all_1s,
+                                  FIB_SOURCE_DHCP,
+                                  FIB_ENTRY_FLAG_LOCAL,
+                                  ADJ_INDEX_INVALID);
+      fib_table_lock (rx_fib_index,
+                      FIB_PROTOCOL_IP4);
+
+      server->server_fib_index = 
+          fib_table_find_or_create_and_lock(FIB_PROTOCOL_IP4,
+                                            server_fib_id);
+
+      vec_validate_init_empty (dpm->dhcp_server_index_by_rx_fib_index,
+                               rx_fib_index,
+                               ~0);
       dpm->dhcp_server_index_by_rx_fib_index[rx_fib_index] = 
-        server - dpm->dhcp_servers;
-    }
+          server - dpm->dhcp_servers;
+  }
 
-  return 0;
-}
+  fib_table_unlock (rx_fib_index,
+                    FIB_PROTOCOL_IP4);
 
-/* Old API, manipulates the default server (only) */
-int dhcp_proxy_set_server (ip4_address_t *addr, ip4_address_t *src_address,
-                           u32 fib_id, int insert_option_82, int is_del)
-{
-  return dhcp_proxy_set_server_2 (addr, src_address, 0 /* rx_fib_id */,
-                                  fib_id /* server_fib_id */, 
-                                  insert_option_82, is_del);
+  return 0;
 }
 
-
 static clib_error_t *
 dhcp_proxy_set_command_fn (vlib_main_t * vm,
                            unformat_input_t * input,
@@ -818,7 +821,6 @@ dhcp_proxy_set_command_fn (vlib_main_t * vm,
   ip4_address_t server_addr, src_addr;
   u32 server_fib_id = 0, rx_fib_id = 0;
   int is_del = 0;
-  int add_option_82 = 0;
   int set_src = 0, set_server = 0;
   
   while (unformat_check_input(input) != UNFORMAT_END_OF_INPUT) 
@@ -833,9 +835,6 @@ dhcp_proxy_set_command_fn (vlib_main_t * vm,
       else if (unformat(input, "src-address %U", 
 			unformat_ip4_address, &src_addr))
         set_src = 1;
-      else if (unformat (input, "add-option-82")
-               || unformat (input, "insert-option-82"))
-        add_option_82 = 1;
       else if (unformat (input, "delete") ||
                unformat (input, "del"))
         is_del = 1;
@@ -847,8 +846,8 @@ dhcp_proxy_set_command_fn (vlib_main_t * vm,
     {
       int rv;
 
-      rv = dhcp_proxy_set_server_2 (&server_addr, &src_addr, rx_fib_id, 
-                                    server_fib_id, add_option_82, is_del);
+      rv = dhcp_proxy_set_server (&server_addr, &src_addr, rx_fib_id, 
+                                  server_fib_id, is_del);
       switch (rv)
         {
         case 0:
@@ -882,7 +881,7 @@ dhcp_proxy_set_command_fn (vlib_main_t * vm,
 
 VLIB_CLI_COMMAND (dhcp_proxy_set_command, static) = {
   .path = "set dhcp proxy",
-  .short_help = "set dhcp proxy [del] server <ip-addr> src-address <ip-addr> [add-option-82] [server-fib-id <n>] [rx-fib-id <n>]",
+  .short_help = "set dhcp proxy [del] server <ip-addr> src-address <ip-addr> [server-fib-id <n>] [rx-fib-id <n>]",
   .function = dhcp_proxy_set_command_fn,
 };
 
@@ -896,8 +895,8 @@ u8 * format_dhcp_proxy_server (u8 * s, va_list * args)
 
   if (dm == 0)
     {
-      s = format (s, "%=16s%=16s%=14s%=14s%=20s", "Server", "Src Address", 
-                  "Server FIB", "RX FIB", "Insert Option 82");
+      s = format (s, "%=16s%=16s%=14s%=14s", "Server", "Src Address", 
+                  "Server FIB", "RX FIB");
       return s;
     }
 
@@ -911,11 +910,10 @@ u8 * format_dhcp_proxy_server (u8 * s, va_list * args)
   if (rx_fib)
     rx_fib_id = rx_fib->table_id;
 
-  s = format (s, "%=16U%=16U%=14u%=14u%=20s",
+  s = format (s, "%=16U%=16U%=14u%=14u",
               format_ip4_address, &server->dhcp_server,
               format_ip4_address, &server->dhcp_src_address,
-              server_fib_id, rx_fib_id,
-              server->insert_option_82 ? "yes" : "no");
+              server_fib_id, rx_fib_id);
   return s;
 }
 
@@ -925,24 +923,22 @@ dhcp_proxy_show_command_fn (vlib_main_t * vm,
                             vlib_cli_command_t * cmd)
 {
   dhcp_proxy_main_t * dpm = &dhcp_proxy_main;
-  ip4_main_t * im = &ip4_main;
   dhcp_server_t * server;
-  u32 server_index;
-  int i;
+  u32 server_index, i;
 
   vlib_cli_output (vm, "%U", format_dhcp_proxy_server, 0 /* header line */,
                    0, 0);
 
-  for (i = 0; i < vec_len (im->fibs); i++)
-    {
-      if (i < vec_len(dpm->dhcp_server_index_by_rx_fib_index))
-        server_index = dpm->dhcp_server_index_by_rx_fib_index[i];
-      else
-        server_index = 0;
+  vec_foreach_index (i, dpm->dhcp_server_index_by_rx_fib_index)
+  {
+      server_index = dpm->dhcp_server_index_by_rx_fib_index[i];
+      if (~0 == server_index)
+          continue;
+
       server = pool_elt_at_index (dpm->dhcp_servers, server_index);
-      if (server->valid)
-        vlib_cli_output (vm, "%U", format_dhcp_proxy_server, dpm, 
-                         server, i);
+
+      vlib_cli_output (vm, "%U", format_dhcp_proxy_server, dpm, 
+                       server, i);
     }
 
   return 0;
@@ -954,50 +950,104 @@ VLIB_CLI_COMMAND (dhcp_proxy_show_command, static) = {
   .function = dhcp_proxy_show_command_fn,
 };
 
+void
+dhcp_proxy_dump (void *opaque,
+                 u32 context)
+{
+  dhcp_proxy_main_t * dpm = &dhcp_proxy_main;
+  ip4_fib_t *s_fib, *r_fib;
+  dhcp_server_t * server;
+  u32 server_index, i;
+  vss_info *v;
+
+  vec_foreach_index (i, dpm->dhcp_server_index_by_rx_fib_index)
+  {
+      server_index = dpm->dhcp_server_index_by_rx_fib_index[i];
+      if (~0 == server_index)
+          continue;
+
+      server = pool_elt_at_index (dpm->dhcp_servers, server_index);
+      v = dhcp_get_vss_info(dpm, i);
+
+      ip46_address_t src_addr = {
+          .ip4 = server->dhcp_src_address,
+      };
+      ip46_address_t server_addr = {
+          .ip4 = server->dhcp_server,
+      };
+
+      s_fib = ip4_fib_get(server->server_fib_index);
+      r_fib = ip4_fib_get(i);
+
+      dhcp_send_details(opaque,
+                        context,
+                        &server_addr,
+                        &src_addr,
+                        s_fib->table_id,
+                        r_fib->table_id,
+                        (v ? v->vpn_id.fib_id : 0),
+                        (v ? v->vpn_id.oui : 0));
+  }
+}
 
-int dhcp_proxy_set_option82_vss(  u32 vrf_id,
-                                  u32 oui,
-                                  u32 fib_id, 
-                                  int is_del)
+int dhcp_proxy_set_option82_vss(u32 tbl_id,
+                                u32 oui,
+                                u32 fib_id, 
+                                int is_del)
 {
   dhcp_proxy_main_t *dm = &dhcp_proxy_main;
-  uword *p;
-  vss_info *a;
-  u32 old_oui=0, old_fib_id=0;
+  vss_info *v = NULL;
+  u32  rx_fib_index;
+  int rc = 0;
   
-  p = hash_get (dm->opt82vss_index_by_vrf_id, vrf_id);
+  rx_fib_index = ip4_fib_table_find_or_create_and_lock(tbl_id);
+  v = dhcp_get_vss_info(dm, rx_fib_index);
 
-  if (p) 
-    {
-      a = pool_elt_at_index (dm->opt82vss, p[0]);
-      if (!a) 
-        return VNET_API_ERROR_NO_SUCH_FIB;
-      old_oui = a->vpn_id.oui;
-      old_fib_id = a->vpn_id.fib_id;
-          
+  if (NULL != v)
+  {
       if (is_del)
-        {
-          if (old_oui == oui &&
-              old_fib_id == fib_id)
-            {
-              pool_put(dm->opt82vss, a);
-              hash_unset (dm->opt82vss_index_by_vrf_id, vrf_id);
-              return 0;
-            }
-          else
-            return VNET_API_ERROR_NO_SUCH_ENTRY;
-        }
-      pool_put(dm->opt82vss, a);
-      hash_unset (dm->opt82vss_index_by_vrf_id, vrf_id);
-  } else if (is_del)
-    return VNET_API_ERROR_NO_SUCH_ENTRY;
-  pool_get (dm->opt82vss, a);
-  memset (a, ~0, sizeof (a[0]));
-  a->vpn_id.oui = oui;
-  a->vpn_id.fib_id = fib_id;
-  hash_set (dm->opt82vss_index_by_vrf_id, vrf_id, a - dm->opt82vss);
+      {
+          /* release the lock held on the table when the VSS
+           * info was created */
+          fib_table_unlock (rx_fib_index,
+                            FIB_PROTOCOL_IP4);
+
+          pool_put (dm->vss, v);
+          dm->vss_index_by_rx_fib_index[rx_fib_index] = ~0;
+      }
+      else
+      {
+          /* this is a modify */
+          v->vpn_id.fib_id = fib_id;
+          v->vpn_id.oui = oui;
+      }
+  }
+  else
+  {
+      if (is_del)
+          rc = VNET_API_ERROR_NO_SUCH_ENTRY;
+      else
+      {
+          /* create a new entry */
+          vec_validate_init_empty(dm->vss_index_by_rx_fib_index,
+                                  rx_fib_index, ~0);
+
+          /* hold a lock on the table whilst the VSS info exist */
+          fib_table_lock (rx_fib_index,
+                          FIB_PROTOCOL_IP4);
+
+          pool_get (dm->vss, v);
+          v->vpn_id.fib_id = fib_id;
+          v->vpn_id.oui = oui;
+          dm->vss_index_by_rx_fib_index[rx_fib_index] = v - dm->vss;
+      }
+  }
+
+  /* Release the lock taken during the create_or_lock at the start */
+  fib_table_unlock (rx_fib_index,
+                    FIB_PROTOCOL_IP4);
   
-  return 0;
+  return (rc);
 }
 
 static clib_error_t *
@@ -1065,20 +1115,20 @@ dhcp_vss_show_command_fn (vlib_main_t * vm,
   
 {
   dhcp_proxy_main_t * dm = &dhcp_proxy_main;
+  ip4_fib_t *fib;
+  u32 *fib_index;
   vss_info *v;
-  u32 oui;
-  u32 fib_id;
-  u32 tbl_id;
-  uword index;
   
   vlib_cli_output (vm, "%=9s%=11s%=12s","Table", "OUI", "VPN-ID");
-  hash_foreach (tbl_id, index, dm->opt82vss_index_by_vrf_id,
+  pool_foreach (fib_index, dm->vss_index_by_rx_fib_index,
   ({
-     v = pool_elt_at_index (dm->opt82vss, index);
-     oui = v->vpn_id.oui;
-     fib_id = v->vpn_id.fib_id;
-     vlib_cli_output (vm, "%=9d 0x%08x%=12d",
-                      tbl_id, oui, fib_id);
+      fib = ip4_fib_get (*fib_index);
+      v = pool_elt_at_index (dm->vss, *fib_index);
+
+      vlib_cli_output (vm, "%=6d%=6d%=12d",
+                       fib->table_id,
+                       v->vpn_id.oui,
+                       v->vpn_id.fib_id);
   }));
   
   return 0;