dhcp: Move to plugin

Type: feature

Change-Id: I3fe27a8ef577741d9a5c4f090ec91cf68fb44fe3
Signed-off-by: Neale Ranns <nranns@cisco.com>

1 files changed, 1090 insertions, 0 deletions

diff --git a/src/plugins/dhcp/dhcp4_proxy_node.c b/src/plugins/dhcp/dhcp4_proxy_node.c
new file mode 100644
index 00000000000..10963c7ff47
--- /dev/null
+++ b/src/plugins/dhcp/dhcp4_proxy_node.c
@@ -0,0 +1,1090 @@
+/*
+ * proxy_node.c: dhcp proxy node processing
+ *
+ * Copyright (c) 2013 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <vlib/vlib.h>
+#include <vnet/pg/pg.h>
+#include <dhcp/dhcp_proxy.h>
+#include <dhcp/client.h>
+#include <vnet/fib/ip4_fib.h>
+
+static char *dhcp_proxy_error_strings[] = {
+#define dhcp_proxy_error(n,s) s,
+#include <dhcp/dhcp4_proxy_error.def>
+#undef dhcp_proxy_error
+};
+
+#define foreach_dhcp_proxy_to_server_input_next \
+  _ (DROP, "error-drop")			\
+  _ (LOOKUP, "ip4-lookup")			\
+  _ (SEND_TO_CLIENT, "dhcp-proxy-to-client")
+
+typedef enum
+{
+#define _(s,n) DHCP_PROXY_TO_SERVER_INPUT_NEXT_##s,
+  foreach_dhcp_proxy_to_server_input_next
+#undef _
+    DHCP_PROXY_TO_SERVER_INPUT_N_NEXT,
+} dhcp_proxy_to_server_input_next_t;
+
+typedef struct
+{
+  /* 0 => to server, 1 => to client */
+  int which;
+  ip4_address_t trace_ip4_address;
+  u32 error;
+  u32 sw_if_index;
+  u32 original_sw_if_index;
+} dhcp_proxy_trace_t;
+
+#define VPP_DHCP_OPTION82_SUB1_SIZE   6
+#define VPP_DHCP_OPTION82_SUB5_SIZE   6
+#define VPP_DHCP_OPTION82_VSS_SIZE    12
+#define VPP_DHCP_OPTION82_SIZE (VPP_DHCP_OPTION82_SUB1_SIZE + \
+                                VPP_DHCP_OPTION82_SUB5_SIZE + \
+                                VPP_DHCP_OPTION82_VSS_SIZE +3)
+
+static vlib_node_registration_t dhcp_proxy_to_server_node;
+static vlib_node_registration_t dhcp_proxy_to_client_node;
+
+static u8 *
+format_dhcp_proxy_trace (u8 * s, va_list * args)
+{
+  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
+  CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
+  dhcp_proxy_trace_t *t = va_arg (*args, dhcp_proxy_trace_t *);
+
+  if (t->which == 0)
+    s = format (s, "DHCP proxy: sent to server %U\n",
+		format_ip4_address, &t->trace_ip4_address, t->error);
+  else
+    s = format (s, "DHCP proxy: broadcast to client from %U\n",
+		format_ip4_address, &t->trace_ip4_address);
+
+  if (t->error != (u32) ~ 0)
+    s = format (s, "  error: %s\n", dhcp_proxy_error_strings[t->error]);
+
+  s = format (s, "  original_sw_if_index: %d, sw_if_index: %d\n",
+	      t->original_sw_if_index, t->sw_if_index);
+
+  return s;
+}
+
+static u8 *
+format_dhcp_proxy_header_with_length (u8 * s, va_list * args)
+{
+  dhcp_header_t *h = va_arg (*args, dhcp_header_t *);
+  u32 max_header_bytes = va_arg (*args, u32);
+  u32 header_bytes;
+
+  header_bytes = sizeof (h[0]);
+  if (max_header_bytes != 0 && header_bytes > max_header_bytes)
+    return format (s, "dhcp header truncated");
+
+  s = format (s, "DHCP Proxy");
+
+  return s;
+}
+
+static uword
+dhcp_proxy_to_server_input (vlib_main_t * vm,
+			    vlib_node_runtime_t * node,
+			    vlib_frame_t * from_frame)
+{
+  u32 n_left_from, next_index, *from, *to_next;
+  dhcp_proxy_main_t *dpm = &dhcp_proxy_main;
+  from = vlib_frame_vector_args (from_frame);
+  n_left_from = from_frame->n_vectors;
+  u32 pkts_to_server = 0, pkts_to_client = 0, pkts_no_server = 0;
+  u32 pkts_no_interface_address = 0;
+  u32 pkts_too_big = 0;
+  ip4_main_t *im = &ip4_main;
+
+  next_index = node->cached_next_index;
+
+  while (n_left_from > 0)
+    {
+      u32 n_left_to_next;
+
+      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
+
+      while (n_left_from > 0 && n_left_to_next > 0)
+	{
+	  u32 bi0;
+	  vlib_buffer_t *b0;
+	  udp_header_t *u0;
+	  dhcp_header_t *h0;
+	  ip4_header_t *ip0;
+	  u32 next0;
+	  u32 old0, new0;
+	  ip_csum_t sum0;
+	  u32 error0 = (u32) ~ 0;
+	  u32 sw_if_index = 0;
+	  u32 original_sw_if_index = 0;
+	  u32 fib_index;
+	  dhcp_proxy_t *proxy;
+	  dhcp_server_t *server;
+	  u32 rx_sw_if_index;
+	  dhcp_option_t *o, *end;
+	  u32 len = 0;
+	  u8 is_discover = 0;
+	  int space_left;
+
+	  bi0 = from[0];
+	  from += 1;
+	  n_left_from -= 1;
+
+	  b0 = vlib_get_buffer (vm, bi0);
+
+	  h0 = vlib_buffer_get_current (b0);
+
+	  /*
+	   * udp_local hands us the DHCP header, need udp hdr,
+	   * ip hdr to relay to server
+	   */
+	  vlib_buffer_advance (b0, -(sizeof (*u0)));
+	  u0 = vlib_buffer_get_current (b0);
+
+	  /* This blows. Return traffic has src_port = 67, dst_port = 67 */
+	  if (u0->src_port ==
+	      clib_net_to_host_u16 (UDP_DST_PORT_dhcp_to_server))
+	    {
+	      vlib_buffer_advance (b0, sizeof (*u0));
+	      next0 = DHCP_PROXY_TO_SERVER_INPUT_NEXT_SEND_TO_CLIENT;
+	      error0 = 0;
+	      pkts_to_client++;
+	      goto do_enqueue;
+	    }
+
+	  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];
+	  proxy = dhcp_get_proxy (dpm, fib_index, FIB_PROTOCOL_IP4);
+
+	  if (PREDICT_FALSE (NULL == proxy))
+	    {
+	      error0 = DHCP_PROXY_ERROR_NO_SERVER;
+	      next0 = DHCP_PROXY_TO_SERVER_INPUT_NEXT_DROP;
+	      pkts_no_server++;
+	      goto do_trace;
+	    }
+
+	  if (!vlib_buffer_chain_linearize (vm, b0))
+	    {
+	      error0 = DHCP_PROXY_ERROR_PKT_TOO_BIG;
+	      next0 = DHCP_PROXY_TO_SERVER_INPUT_NEXT_DROP;
+	      pkts_too_big++;
+	      goto do_trace;
+	    }
+	  space_left = vlib_buffer_space_left_at_end (vm, b0);
+	  /* cant parse chains...
+	   * and we need some space for option 82*/
+	  if ((b0->flags & VLIB_BUFFER_NEXT_PRESENT) != 0 ||
+	      space_left < VPP_DHCP_OPTION82_SIZE)
+	    {
+	      error0 = DHCP_PROXY_ERROR_PKT_TOO_BIG;
+	      next0 = DHCP_PROXY_TO_SERVER_INPUT_NEXT_DROP;
+	      pkts_too_big++;
+	      goto do_trace;
+	    }
+
+	  server = &proxy->dhcp_servers[0];
+	  vlib_buffer_advance (b0, -(sizeof (*ip0)));
+	  ip0 = vlib_buffer_get_current (b0);
+
+	  /* disable UDP checksum */
+	  u0->checksum = 0;
+	  sum0 = ip0->checksum;
+	  old0 = ip0->dst_address.as_u32;
+	  new0 = server->dhcp_server.ip4.as_u32;
+	  ip0->dst_address.as_u32 = server->dhcp_server.ip4.as_u32;
+	  sum0 = ip_csum_update (sum0, old0, new0,
+				 ip4_header_t /* structure */ ,
+				 dst_address /* changed member */ );
+	  ip0->checksum = ip_csum_fold (sum0);
+
+	  sum0 = ip0->checksum;
+	  old0 = ip0->src_address.as_u32;
+	  new0 = proxy->dhcp_src_address.ip4.as_u32;
+	  ip0->src_address.as_u32 = new0;
+	  sum0 = ip_csum_update (sum0, old0, new0,
+				 ip4_header_t /* structure */ ,
+				 src_address /* changed member */ );
+	  ip0->checksum = ip_csum_fold (sum0);
+
+	  /* Send to DHCP server via the configured FIB */
+	  vnet_buffer (b0)->sw_if_index[VLIB_TX] = server->server_fib_index;
+
+	  h0->gateway_ip_address = proxy->dhcp_src_address.ip4;
+	  pkts_to_server++;
+
+	  o = h0->options;
+	  end = (void *) vlib_buffer_get_tail (b0);
+
+	  /* TLVs are not performance-friendly... */
+	  while (o->option != DHCP_PACKET_OPTION_END && o < end)
+	    {
+	      if (DHCP_PACKET_OPTION_MSG_TYPE == o->option)
+		{
+		  if (DHCP_PACKET_DISCOVER == o->data[0])
+		    {
+		      is_discover = 1;
+		    }
+		}
+	      o = (dhcp_option_t *) (o->data + o->length);
+	    }
+
+	  if (o->option == DHCP_PACKET_OPTION_END && o <= end)
+	    {
+	      vnet_main_t *vnm = vnet_get_main ();
+	      u16 old_l0, new_l0;
+	      ip4_address_t _ia0, *ia0 = &_ia0;
+	      dhcp_vss_t *vss;
+	      vnet_sw_interface_t *swif;
+
+	      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;
+
+	      /*
+	       * 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 */
+	      u32 *o_ifid = (u32 *) & o->data[2];
+	      *o_ifid = clib_host_to_net_u32 (original_sw_if_index);
+	      o->data[6] = 5;	/* suboption 5 (client RX intfc address) */
+	      o->data[7] = 4;	/* length 4 */
+	      u32 *o_addr = (u32 *) & o->data[8];
+	      *o_addr = ia0->as_u32;
+	      o->data[12] = DHCP_PACKET_OPTION_END;
+
+	      vss = dhcp_get_vss_info (dpm, fib_index, FIB_PROTOCOL_IP4);
+	      if (vss)
+		{
+		  u32 id_len;	/* length of VPN ID */
+
+		  if (vss->vss_type == VSS_TYPE_VPN_ID)
+		    {
+		      id_len = sizeof (vss->vpn_id);	/* vpn_id is 7 bytes */
+		      memcpy (&o->data[15], vss->vpn_id, id_len);
+		    }
+		  else if (vss->vss_type == VSS_TYPE_ASCII)
+		    {
+		      id_len = vec_len (vss->vpn_ascii_id);
+		      memcpy (&o->data[15], vss->vpn_ascii_id, id_len);
+		    }
+		  else		/* must be VSS_TYPE_DEFAULT, no VPN ID */
+		    id_len = 0;
+
+		  o->data[12] = 151;	/* vss suboption */
+		  o->data[13] = id_len + 1;	/* length: vss_type + id_len */
+		  o->data[14] = vss->vss_type;	/* vss option type */
+		  o->data[15 + id_len] = 152;	/* vss control suboption */
+		  o->data[16 + id_len] = 0;	/* length */
+		  o->data[17 + id_len] = DHCP_PACKET_OPTION_END;	/* "end-of-options" (0xFF) */
+		  /* 5 bytes for suboption headers 151+len, 152+len and 0xFF */
+		  o->length += id_len + 5;
+		}
+
+	      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;
+
+	  /*
+	   * If we have multiple servers configured and this is the
+	   * client's discover message, then send copies to each of
+	   * those servers
+	   */
+	  if (is_discover && vec_len (proxy->dhcp_servers) > 1)
+	    {
+	      u32 ii;
+
+	      for (ii = 1; ii < vec_len (proxy->dhcp_servers); ii++)
+		{
+		  vlib_buffer_t *c0;
+		  u32 ci0;
+
+		  c0 = vlib_buffer_copy (vm, b0);
+		  VLIB_BUFFER_TRACE_TRAJECTORY_INIT (c0);
+		  ci0 = vlib_get_buffer_index (vm, c0);
+		  server = &proxy->dhcp_servers[ii];
+
+		  ip0 = vlib_buffer_get_current (c0);
+
+		  sum0 = ip0->checksum;
+		  old0 = ip0->dst_address.as_u32;
+		  new0 = server->dhcp_server.ip4.as_u32;
+		  ip0->dst_address.as_u32 = server->dhcp_server.ip4.as_u32;
+		  sum0 = ip_csum_update (sum0, old0, new0,
+					 ip4_header_t /* structure */ ,
+					 dst_address /* changed member */ );
+		  ip0->checksum = ip_csum_fold (sum0);
+
+		  to_next[0] = ci0;
+		  to_next += 1;
+		  n_left_to_next -= 1;
+
+		  vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
+						   to_next, n_left_to_next,
+						   ci0, next0);
+
+		  if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
+		    {
+		      dhcp_proxy_trace_t *tr;
+
+		      tr = vlib_add_trace (vm, node, c0, sizeof (*tr));
+		      tr->which = 0;	/* to server */
+		      tr->error = error0;
+		      tr->original_sw_if_index = original_sw_if_index;
+		      tr->sw_if_index = sw_if_index;
+		      if (next0 == DHCP_PROXY_TO_SERVER_INPUT_NEXT_LOOKUP)
+			tr->trace_ip4_address.as_u32 =
+			  server->dhcp_server.ip4.as_u32;
+		    }
+
+		  if (PREDICT_FALSE (0 == n_left_to_next))
+		    {
+		      vlib_put_next_frame (vm, node, next_index,
+					   n_left_to_next);
+		      vlib_get_next_frame (vm, node, next_index,
+					   to_next, n_left_to_next);
+		    }
+		}
+	    }
+	do_trace:
+	  if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
+	    {
+	      dhcp_proxy_trace_t *tr = vlib_add_trace (vm, node,
+						       b0, sizeof (*tr));
+	      tr->which = 0;	/* to server */
+	      tr->error = error0;
+	      tr->original_sw_if_index = original_sw_if_index;
+	      tr->sw_if_index = sw_if_index;
+	      if (next0 == DHCP_PROXY_TO_SERVER_INPUT_NEXT_LOOKUP)
+		tr->trace_ip4_address.as_u32 =
+		  proxy->dhcp_servers[0].dhcp_server.ip4.as_u32;
+	    }
+
+	do_enqueue:
+	  to_next[0] = bi0;
+	  to_next += 1;
+	  n_left_to_next -= 1;
+
+	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
+					   to_next, n_left_to_next,
+					   bi0, next0);
+	}
+
+      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+    }
+  vlib_node_increment_counter (vm, dhcp_proxy_to_server_node.index,
+			       DHCP_PROXY_ERROR_RELAY_TO_CLIENT,
+			       pkts_to_client);
+  vlib_node_increment_counter (vm, dhcp_proxy_to_server_node.index,
+			       DHCP_PROXY_ERROR_RELAY_TO_SERVER,
+			       pkts_to_server);
+  vlib_node_increment_counter (vm, dhcp_proxy_to_server_node.index,
+			       DHCP_PROXY_ERROR_NO_SERVER, pkts_no_server);
+  vlib_node_increment_counter (vm, dhcp_proxy_to_server_node.index,
+			       DHCP_PROXY_ERROR_NO_INTERFACE_ADDRESS,
+			       pkts_no_interface_address);
+  vlib_node_increment_counter (vm, dhcp_proxy_to_server_node.index,
+			       DHCP_PROXY_ERROR_PKT_TOO_BIG, pkts_too_big);
+  return from_frame->n_vectors;
+}
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (dhcp_proxy_to_server_node, static) = {
+  .function = dhcp_proxy_to_server_input,
+  .name = "dhcp-proxy-to-server",
+  /* Takes a vector of packets. */
+  .vector_size = sizeof (u32),
+
+  .n_errors = DHCP_PROXY_N_ERROR,
+  .error_strings = dhcp_proxy_error_strings,
+
+  .n_next_nodes = DHCP_PROXY_TO_SERVER_INPUT_N_NEXT,
+  .next_nodes = {
+#define _(s,n) [DHCP_PROXY_TO_SERVER_INPUT_NEXT_##s] = n,
+    foreach_dhcp_proxy_to_server_input_next
+#undef _
+  },
+
+  .format_buffer = format_dhcp_proxy_header_with_length,
+  .format_trace = format_dhcp_proxy_trace,
+#if 0
+  .unformat_buffer = unformat_dhcp_proxy_header,
+#endif
+};
+/* *INDENT-ON* */
+
+static uword
+dhcp_proxy_to_client_input (vlib_main_t * vm,
+			    vlib_node_runtime_t * node,
+			    vlib_frame_t * from_frame)
+{
+  u32 n_left_from, *from;
+  ethernet_main_t *em = vnet_get_ethernet_main ();
+  dhcp_proxy_main_t *dpm = &dhcp_proxy_main;
+  vnet_main_t *vnm = vnet_get_main ();
+  ip4_main_t *im = &ip4_main;
+
+  from = vlib_frame_vector_args (from_frame);
+  n_left_from = from_frame->n_vectors;
+
+  while (n_left_from > 0)
+    {
+      u32 bi0;
+      vlib_buffer_t *b0;
+      udp_header_t *u0;
+      dhcp_header_t *h0;
+      ip4_header_t *ip0 = 0;
+      ip4_address_t *ia0 = 0;
+      u32 old0, new0;
+      ip_csum_t sum0;
+      ethernet_interface_t *ei0;
+      ethernet_header_t *mac0;
+      vnet_hw_interface_t *hi0;
+      vlib_frame_t *f0;
+      u32 *to_next0;
+      u32 sw_if_index = ~0;
+      vnet_sw_interface_t *si0;
+      u32 error0 = (u32) ~ 0;
+      vnet_sw_interface_t *swif;
+      u32 fib_index;
+      dhcp_proxy_t *proxy;
+      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;
+
+      b0 = vlib_get_buffer (vm, bi0);
+      h0 = vlib_buffer_get_current (b0);
+
+      /*
+       * udp_local hands us the DHCP header, need udp hdr,
+       * ip hdr to relay to client
+       */
+      vlib_buffer_advance (b0, -(sizeof (*u0)));
+      u0 = vlib_buffer_get_current (b0);
+
+      vlib_buffer_advance (b0, -(sizeof (*ip0)));
+      ip0 = vlib_buffer_get_current (b0);
+
+      /* Consumed by dhcp client code? */
+      if (dhcp_client_for_us (bi0, b0, ip0, u0, h0))
+	continue;
+
+      if (1 /* dpm->insert_option_82 */ )
+	{
+	  /* linearize needed to "unclone" and scan options */
+	  int rv = vlib_buffer_chain_linearize (vm, b0);
+	  if ((b0->flags & VLIB_BUFFER_NEXT_PRESENT) != 0 || !rv)
+	    {
+	      error0 = DHCP_PROXY_ERROR_PKT_TOO_BIG;
+	      goto drop_packet;
+	    }
+
+	  dhcp_option_t *o = h0->options, *end =
+	    (void *) vlib_buffer_get_tail (b0);
+
+	  /* Parse through TLVs looking for option 82.
+	     The circuit-ID is the FIB number we need
+	     to track down the client-facing interface */
+
+	  while (o->option != DHCP_PACKET_OPTION_END && o < end)
+	    {
+	      if (o->option == 82)
+		{
+		  u32 vss_exist = 0;
+		  u32 vss_ctrl = 0;
+		  dhcp_option_t *sub = (dhcp_option_t *) & o->data[0];
+		  dhcp_option_t *subend =
+		    (dhcp_option_t *) (o->data + o->length);
+		  while (sub->option != DHCP_PACKET_OPTION_END
+			 && sub < subend)
+		    {
+		      /* If this is one of ours, it will have
+		         total length 12, circuit-id suboption type,
+		         and the sw_if_index */
+		      if (sub->option == 1 && sub->length == 4)
+			{
+			  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;
+		      sub = (dhcp_option_t *) (sub->data + sub->length);
+		    }
+		  if (vss_ctrl && vss_exist)
+		    vlib_node_increment_counter
+		      (vm, dhcp_proxy_to_client_node.index,
+		       DHCP_PROXY_ERROR_OPTION_82_VSS_NOT_PROCESSED, 1);
+
+		}
+	      o = (dhcp_option_t *) (o->data + o->length);
+	    }
+	}
+
+      if (sw_if_index == (u32) ~ 0)
+	{
+	  error0 = DHCP_PROXY_ERROR_NO_OPTION_82;
+
+	drop_packet:
+	  vlib_node_increment_counter (vm, dhcp_proxy_to_client_node.index,
+				       error0, 1);
+	  f0 = vlib_get_frame_to_node (vm, dpm->error_drop_node_index);
+	  to_next0 = vlib_frame_vector_args (f0);
+	  to_next0[0] = bi0;
+	  f0->n_vectors = 1;
+	  vlib_put_frame_to_node (vm, dpm->error_drop_node_index, f0);
+	  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_ITF;
+	  goto drop_packet;
+	}
+
+      fib_index = im->fib_index_by_sw_if_index[sw_if_index];
+      proxy = dhcp_get_proxy (dpm, fib_index, FIB_PROTOCOL_IP4);
+
+      if (PREDICT_FALSE (NULL == proxy))
+	{
+	  error0 = DHCP_PROXY_ERROR_NO_SERVER;
+	  goto drop_packet;
+	}
+
+      vec_foreach (server, proxy->dhcp_servers)
+      {
+	if (ip0->src_address.as_u32 == server->dhcp_server.ip4.as_u32)
+	  {
+	    goto server_found;
+	  }
+      }
+
+      error0 = DHCP_PROXY_ERROR_BAD_SVR_FIB_OR_ADDRESS;
+      goto drop_packet;
+
+    server_found:
+      vnet_buffer (b0)->sw_if_index[VLIB_TX] = sw_if_index;
+
+      swif = vnet_get_sw_interface (vnm, sw_if_index);
+      original_sw_if_index = sw_if_index;
+      if (swif->flags & VNET_SW_INTERFACE_FLAG_UNNUMBERED)
+	sw_if_index = swif->unnumbered_sw_if_index;
+
+      ia0 = ip4_interface_first_address (&ip4_main, sw_if_index, 0);
+      if (ia0 == 0)
+	{
+	  error0 = DHCP_PROXY_ERROR_NO_INTERFACE_ADDRESS;
+	  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;
+      old0 = ip0->dst_address.as_u32;
+      new0 = 0xFFFFFFFF;
+      ip0->dst_address.as_u32 = new0;
+      sum0 = ip_csum_update (sum0, old0, new0, ip4_header_t /* structure */ ,
+			     dst_address /* offset of changed member */ );
+      ip0->checksum = ip_csum_fold (sum0);
+
+      sum0 = ip0->checksum;
+      old0 = ip0->src_address.as_u32;
+      new0 = ia0->as_u32;
+      ip0->src_address.as_u32 = new0;
+      sum0 = ip_csum_update (sum0, old0, new0, ip4_header_t /* structure */ ,
+			     src_address /* offset of changed member */ );
+      ip0->checksum = ip_csum_fold (sum0);
+
+      vlib_buffer_advance (b0, -(sizeof (ethernet_header_t)));
+      si0 = vnet_get_sw_interface (vnm, original_sw_if_index);
+      if (si0->type == VNET_SW_INTERFACE_TYPE_SUB)
+	vlib_buffer_advance (b0, -4 /* space for VLAN tag */ );
+
+      mac0 = vlib_buffer_get_current (b0);
+
+      hi0 = vnet_get_sup_hw_interface (vnm, original_sw_if_index);
+      ei0 = pool_elt_at_index (em->interfaces, hi0->hw_instance);
+      clib_memcpy (mac0->src_address, ei0->address, sizeof (ei0->address));
+      clib_memset (mac0->dst_address, 0xff, sizeof (mac0->dst_address));
+      mac0->type = (si0->type == VNET_SW_INTERFACE_TYPE_SUB) ?
+	clib_net_to_host_u16 (0x8100) : clib_net_to_host_u16 (0x0800);
+
+      if (si0->type == VNET_SW_INTERFACE_TYPE_SUB)
+	{
+	  u32 *vlan_tag = (u32 *) (mac0 + 1);
+	  u32 tmp;
+	  tmp = (si0->sub.id << 16) | 0x0800;
+	  *vlan_tag = clib_host_to_net_u32 (tmp);
+	}
+
+      /* $$$ This needs to be rewritten, for sure */
+      f0 = vlib_get_frame_to_node (vm, hi0->output_node_index);
+      to_next0 = vlib_frame_vector_args (f0);
+      to_next0[0] = bi0;
+      f0->n_vectors = 1;
+      vlib_put_frame_to_node (vm, hi0->output_node_index, f0);
+
+    do_trace:
+      if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
+	{
+	  dhcp_proxy_trace_t *tr = vlib_add_trace (vm, node,
+						   b0, sizeof (*tr));
+	  tr->which = 1;	/* to client */
+	  tr->trace_ip4_address.as_u32 = ia0 ? ia0->as_u32 : 0;
+	  tr->error = error0;
+	  tr->original_sw_if_index = original_sw_if_index;
+	  tr->sw_if_index = sw_if_index;
+	}
+    }
+
+  return from_frame->n_vectors;
+}
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (dhcp_proxy_to_client_node, static) = {
+  .function = dhcp_proxy_to_client_input,
+  .name = "dhcp-proxy-to-client",
+  /* Takes a vector of packets. */
+  .vector_size = sizeof (u32),
+
+  .n_errors = DHCP_PROXY_N_ERROR,
+  .error_strings = dhcp_proxy_error_strings,
+  .format_buffer = format_dhcp_proxy_header_with_length,
+  .format_trace = format_dhcp_proxy_trace,
+#if 0
+  .unformat_buffer = unformat_dhcp_proxy_header,
+#endif
+};
+/* *INDENT-ON* */
+
+void
+dhcp_maybe_register_udp_ports (dhcp_port_reg_flags_t ports)
+{
+  dhcp_proxy_main_t *dm = &dhcp_proxy_main;
+  vlib_main_t *vm = dm->vlib_main;
+  int port_regs_diff = dm->udp_ports_registered ^ ports;
+
+  if (!port_regs_diff)
+    return;
+
+  if ((port_regs_diff & DHCP_PORT_REG_CLIENT) & ports)
+    udp_register_dst_port (vm, UDP_DST_PORT_dhcp_to_client,
+			   dhcp_proxy_to_client_node.index, 1 /* is_ip4 */ );
+
+  if ((port_regs_diff & DHCP_PORT_REG_SERVER) & ports)
+    udp_register_dst_port (vm, UDP_DST_PORT_dhcp_to_server,
+			   dhcp_proxy_to_server_node.index, 1 /* is_ip4 */ );
+
+  dm->udp_ports_registered |= ports;
+}
+
+static clib_error_t *
+dhcp4_proxy_init (vlib_main_t * vm)
+{
+  dhcp_proxy_main_t *dm = &dhcp_proxy_main;
+  vlib_node_t *error_drop_node;
+
+  error_drop_node = vlib_get_node_by_name (vm, (u8 *) "error-drop");
+  dm->error_drop_node_index = error_drop_node->index;
+  dm->vlib_main = vm;
+
+  return 0;
+}
+
+
+VLIB_INIT_FUNCTION (dhcp4_proxy_init);
+
+int
+dhcp4_proxy_set_server (ip46_address_t * addr,
+			ip46_address_t * src_addr,
+			u32 rx_table_id, u32 server_table_id, int is_del)
+{
+  u32 rx_fib_index = 0;
+  int rc = 0;
+
+  const fib_prefix_t all_1s = {
+    .fp_len = 32,
+    .fp_addr.ip4.as_u32 = 0xffffffff,
+    .fp_proto = FIB_PROTOCOL_IP4,
+  };
+
+  if (ip46_address_is_zero (addr))
+    return VNET_API_ERROR_INVALID_DST_ADDRESS;
+
+  if (ip46_address_is_zero (src_addr))
+    return VNET_API_ERROR_INVALID_SRC_ADDRESS;
+
+  dhcp_maybe_register_udp_ports (DHCP_PORT_REG_CLIENT | DHCP_PORT_REG_SERVER);
+
+  rx_fib_index = fib_table_find_or_create_and_lock (FIB_PROTOCOL_IP4,
+						    rx_table_id,
+						    FIB_SOURCE_DHCP);
+
+  if (is_del)
+    {
+      if (dhcp_proxy_server_del (FIB_PROTOCOL_IP4, rx_fib_index,
+				 addr, server_table_id))
+	{
+	  fib_table_entry_special_remove (rx_fib_index,
+					  &all_1s, FIB_SOURCE_DHCP);
+	  fib_table_unlock (rx_fib_index, FIB_PROTOCOL_IP4, FIB_SOURCE_DHCP);
+	}
+    }
+  else
+    {
+      if (dhcp_proxy_server_add (FIB_PROTOCOL_IP4,
+				 addr, src_addr,
+				 rx_fib_index, server_table_id))
+	{
+	  fib_table_entry_special_add (rx_fib_index,
+				       &all_1s,
+				       FIB_SOURCE_DHCP, FIB_ENTRY_FLAG_LOCAL);
+	  fib_table_lock (rx_fib_index, FIB_PROTOCOL_IP4, FIB_SOURCE_DHCP);
+	}
+    }
+  fib_table_unlock (rx_fib_index, FIB_PROTOCOL_IP4, FIB_SOURCE_DHCP);
+
+  return (rc);
+}
+
+static clib_error_t *
+dhcp4_proxy_set_command_fn (vlib_main_t * vm,
+			    unformat_input_t * input,
+			    vlib_cli_command_t * cmd)
+{
+  ip46_address_t server_addr, src_addr;
+  u32 server_table_id = 0, rx_table_id = 0;
+  int is_del = 0;
+  int set_src = 0, set_server = 0;
+
+  clib_memset (&server_addr, 0, sizeof (server_addr));
+  clib_memset (&src_addr, 0, sizeof (src_addr));
+
+  while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (input, "server %U",
+		    unformat_ip4_address, &server_addr.ip4))
+	set_server = 1;
+      else if (unformat (input, "server-fib-id %d", &server_table_id))
+	;
+      else if (unformat (input, "rx-fib-id %d", &rx_table_id))
+	;
+      else if (unformat (input, "src-address %U",
+			 unformat_ip4_address, &src_addr.ip4))
+	set_src = 1;
+      else if (unformat (input, "delete") || unformat (input, "del"))
+	is_del = 1;
+      else
+	break;
+    }
+
+  if (is_del || (set_server && set_src))
+    {
+      int rv;
+
+      rv = dhcp4_proxy_set_server (&server_addr, &src_addr, rx_table_id,
+				   server_table_id, is_del);
+      switch (rv)
+	{
+	case 0:
+	  return 0;
+
+	case VNET_API_ERROR_INVALID_DST_ADDRESS:
+	  return clib_error_return (0, "Invalid server address");
+
+	case VNET_API_ERROR_INVALID_SRC_ADDRESS:
+	  return clib_error_return (0, "Invalid src address");
+
+	case VNET_API_ERROR_NO_SUCH_ENTRY:
+	  return clib_error_return
+	    (0, "Fib id %d: no per-fib DHCP server configured", rx_table_id);
+
+	default:
+	  return clib_error_return (0, "BUG: rv %d", rv);
+	}
+    }
+  else
+    return clib_error_return (0, "parse error`%U'",
+			      format_unformat_error, input);
+}
+
+/* *INDENT-OFF* */
+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> [server-fib-id <n>] [rx-fib-id <n>]",
+  .function = dhcp4_proxy_set_command_fn,
+};
+/* *INDENT-ON* */
+
+static u8 *
+format_dhcp4_proxy_server (u8 * s, va_list * args)
+{
+  dhcp_proxy_t *proxy = va_arg (*args, dhcp_proxy_t *);
+  ip4_fib_t *rx_fib, *server_fib;
+  dhcp_server_t *server;
+
+  if (proxy == 0)
+    {
+      s = format (s, "%=14s%=16s%s", "RX FIB", "Src Address",
+		  "Servers FIB,Address");
+      return s;
+    }
+
+  rx_fib = ip4_fib_get (proxy->rx_fib_index);
+
+  s = format (s, "%=14u%=16U",
+	      rx_fib->table_id,
+	      format_ip46_address, &proxy->dhcp_src_address, IP46_TYPE_ANY);
+
+  vec_foreach (server, proxy->dhcp_servers)
+  {
+    server_fib = ip4_fib_get (server->server_fib_index);
+    s = format (s, "%u,%U  ",
+		server_fib->table_id,
+		format_ip46_address, &server->dhcp_server, IP46_TYPE_ANY);
+  }
+  return s;
+}
+
+static int
+dhcp4_proxy_show_walk (dhcp_proxy_t * server, void *ctx)
+{
+  vlib_main_t *vm = ctx;
+
+  vlib_cli_output (vm, "%U", format_dhcp4_proxy_server, server);
+
+  return (1);
+}
+
+static clib_error_t *
+dhcp4_proxy_show_command_fn (vlib_main_t * vm,
+			     unformat_input_t * input,
+			     vlib_cli_command_t * cmd)
+{
+  vlib_cli_output (vm, "%U", format_dhcp4_proxy_server,
+		   NULL /* header line */ );
+
+  dhcp_proxy_walk (FIB_PROTOCOL_IP4, dhcp4_proxy_show_walk, vm);
+
+  return (NULL);
+}
+
+/* *INDENT-OFF* */
+VLIB_CLI_COMMAND (dhcp_proxy_show_command, static) = {
+  .path = "show dhcp proxy",
+  .short_help = "Display dhcp proxy server info",
+  .function = dhcp4_proxy_show_command_fn,
+};
+/* *INDENT-ON* */
+
+static clib_error_t *
+dhcp_option_82_vss_fn (vlib_main_t * vm,
+		       unformat_input_t * input, vlib_cli_command_t * cmd)
+{
+  u8 is_del = 0, vss_type = VSS_TYPE_DEFAULT;
+  u32 oui = 0, fib_id = 0, tbl_id = ~0;
+  u8 *vpn_ascii_id = 0;
+
+  while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (input, "table %d", &tbl_id))
+	;
+      else if (unformat (input, "oui %d", &oui))
+	vss_type = VSS_TYPE_VPN_ID;
+      else if (unformat (input, "vpn-id %d", &fib_id))
+	vss_type = VSS_TYPE_VPN_ID;
+      else if (unformat (input, "vpn-ascii-id %s", &vpn_ascii_id))
+	vss_type = VSS_TYPE_ASCII;
+      else if (unformat (input, "delete") || unformat (input, "del"))
+	is_del = 1;
+      else
+	break;
+    }
+
+  if (tbl_id == ~0)
+    return clib_error_return (0, "no table ID specified.");
+
+  int rv = dhcp_proxy_set_vss (FIB_PROTOCOL_IP4, tbl_id, vss_type,
+			       vpn_ascii_id, oui, fib_id, is_del);
+  switch (rv)
+    {
+    case 0:
+      return 0;
+    case VNET_API_ERROR_NO_SUCH_ENTRY:
+      return clib_error_return (0,
+				"option 82 vss for table %d not found in in pool.",
+				tbl_id);
+    default:
+      return clib_error_return (0, "BUG: rv %d", rv);
+
+    }
+}
+
+/* *INDENT-OFF* */
+VLIB_CLI_COMMAND (dhcp_proxy_vss_command,static) = {
+  .path = "set dhcp option-82 vss",
+  .short_help = "set dhcp option-82 vss [del] table <table id> [oui <n> vpn-id <n> | vpn-ascii-id <text>]",
+  .function = dhcp_option_82_vss_fn,
+};
+/* *INDENT-ON* */
+
+static clib_error_t *
+dhcp_vss_show_command_fn (vlib_main_t * vm,
+			  unformat_input_t * input, vlib_cli_command_t * cmd)
+{
+  dhcp_vss_walk (FIB_PROTOCOL_IP4, dhcp_vss_show_walk, vm);
+
+  return (NULL);
+}
+
+/* *INDENT-OFF* */
+VLIB_CLI_COMMAND (dhcp_proxy_vss_show_command, static) = {
+  .path = "show dhcp vss",
+  .short_help = "show dhcp VSS",
+  .function = dhcp_vss_show_command_fn,
+};
+/* *INDENT-ON* */
+
+static clib_error_t *
+dhcp_option_82_address_show_command_fn (vlib_main_t * vm,
+					unformat_input_t * input,
+					vlib_cli_command_t * cmd)
+{
+  vnet_main_t *vnm = vnet_get_main ();
+  u32 sw_if_index0 = 0, sw_if_index;
+  vnet_sw_interface_t *swif;
+  ip4_address_t *ia0;
+
+  while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
+    {
+
+      if (unformat (input, "%U",
+		    unformat_vnet_sw_interface, vnm, &sw_if_index0))
+	{
+	  swif = vnet_get_sw_interface (vnm, sw_if_index0);
+	  sw_if_index = (swif->flags & VNET_SW_INTERFACE_FLAG_UNNUMBERED) ?
+	    swif->unnumbered_sw_if_index : sw_if_index0;
+	  ia0 = ip4_interface_first_address (&ip4_main, sw_if_index, 0);
+	  if (ia0)
+	    {
+	      vlib_cli_output (vm, "%=20s%=20s", "interface",
+			       "source IP address");
+
+	      vlib_cli_output (vm, "%=20U%=20U",
+			       format_vnet_sw_if_index_name,
+			       vnm, sw_if_index0, format_ip4_address, ia0);
+	    }
+	  else
+	    vlib_cli_output (vm, "%=34s %=20U",
+			     "No IPv4 address configured on",
+			     format_vnet_sw_if_index_name, vnm, sw_if_index);
+	}
+      else
+	break;
+    }
+
+  return 0;
+}
+
+/* *INDENT-OFF* */
+VLIB_CLI_COMMAND (dhcp_proxy_address_show_command,static) = {
+  .path = "show dhcp option-82-address interface",
+  .short_help = "show dhcp option-82-address interface <interface>",
+  .function = dhcp_option_82_address_show_command_fn,
+};
+/* *INDENT-ON* */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */