Consolidate DHCP v4 and V6 implementation. No functional change intended

The DHCP proxy and VSS information maintained by VPP is the same for v4 and v6, so we can manage this state using the same code.
Packet handling is cleary different, so this is kept separate.

Change-Id: I10f10cc1f7f19debcd4c4b099c6de64e56bb0c69
Signed-off-by: Neale Ranns <nranns@cisco.com>

1 files changed, 1065 insertions, 0 deletions

diff --git a/src/vnet/dhcp/dhcp6_proxy_node.c b/src/vnet/dhcp/dhcp6_proxy_node.c
new file mode 100644
index 00000000000..ed44977d76b
--- /dev/null
+++ b/src/vnet/dhcp/dhcp6_proxy_node.c
@@ -0,0 +1,1065 @@
+/*
+ * dhcp6_proxy_node.c: dhcpv6 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 <vnet/dhcp/dhcp_proxy.h>
+#include <vnet/dhcp/dhcp6_packet.h>
+#include <vnet/fib/ip6_fib.h>
+#include <vnet/mfib/mfib_table.h>
+#include <vnet/mfib/ip6_mfib.h>
+
+static char * dhcpv6_proxy_error_strings[] = {
+#define dhcpv6_proxy_error(n,s) s,
+#include <vnet/dhcp/dhcp6_proxy_error.def>
+#undef dhcpv6_proxy_error
+};
+
+#define foreach_dhcpv6_proxy_to_server_input_next \
+  _ (DROP, "error-drop")			\
+  _ (LOOKUP, "ip6-lookup")                      \
+  _ (SEND_TO_CLIENT, "dhcpv6-proxy-to-client")
+
+
+typedef enum {
+#define _(s,n) DHCPV6_PROXY_TO_SERVER_INPUT_NEXT_##s,
+  foreach_dhcpv6_proxy_to_server_input_next
+#undef _
+  DHCPV6_PROXY_TO_SERVER_INPUT_N_NEXT,
+} dhcpv6_proxy_to_server_input_next_t;
+
+typedef struct {
+  /* 0 => to server, 1 => to client */
+  int which;
+  u8 packet_data[64];
+  u32 error;
+  u32 sw_if_index;
+  u32 original_sw_if_index;
+} dhcpv6_proxy_trace_t;
+
+static vlib_node_registration_t dhcpv6_proxy_to_server_node;
+static vlib_node_registration_t dhcpv6_proxy_to_client_node;
+
+/* all DHCP servers address */
+static ip6_address_t all_dhcpv6_server_address;
+static ip6_address_t all_dhcpv6_server_relay_agent_address;
+
+static u8 *
+format_dhcpv6_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 *);
+  dhcpv6_proxy_trace_t * t = va_arg (*args, dhcpv6_proxy_trace_t *);
+
+  if (t->which == 0)
+    s = format (s, "DHCPV6 proxy: sent to server %U",
+                format_ip6_address, &t->packet_data, sizeof (ip6_address_t));
+  else
+    s = format (s, "DHCPV6 proxy: sent to client from %U",
+                format_ip6_address, &t->packet_data, sizeof (ip6_address_t));
+  if (t->error != (u32)~0)
+    s = format (s, " error: %s\n", dhcpv6_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_dhcpv6_proxy_header_with_length (u8 * s, va_list * args)
+{
+  dhcpv6_header_t * h = va_arg (*args, dhcpv6_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, "dhcpv6 header truncated");
+
+  s = format (s, "DHCPV6 Proxy");
+
+  return s;
+}
+/* get first interface address */
+static ip6_address_t *
+ip6_interface_first_global_or_site_address (ip6_main_t * im, u32 sw_if_index)
+{
+  ip_lookup_main_t * lm = &im->lookup_main;
+  ip_interface_address_t * ia = 0;
+  ip6_address_t * result = 0;
+
+  foreach_ip_interface_address (lm, ia, sw_if_index,
+                                1 /* honor unnumbered */,
+  ({
+    ip6_address_t * a = ip_interface_address_get_address (lm, ia);
+    if ((a->as_u8[0] & 0xe0) == 0x20 ||
+        (a->as_u8[0] & 0xfe) == 0xfc)  {
+        result = a;
+        break;
+    }
+  }));
+  return result;
+}
+
+static inline void copy_ip6_address (ip6_address_t *dst,
+                                     ip6_address_t *src) 
+{
+  dst->as_u64[0] = src->as_u64[0];
+  dst->as_u64[1] = src->as_u64[1];
+} 
+
+static uword
+dhcpv6_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, pkts_no_exceeding_max_hop=0;
+  u32 pkts_no_src_address=0;
+  u32 pkts_wrong_msg_type=0;
+  u32 pkts_too_big=0;
+  ip6_main_t * im = &ip6_main;
+  ip6_address_t * src;
+  int bogus_length;
+  dhcp_server_t * server;
+  u32  rx_fib_idx = 0, server_fib_idx = 0;
+
+  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)
+	{
+          vnet_main_t *vnm = vnet_get_main();
+          u32 sw_if_index = 0;
+          u32 rx_sw_if_index = 0;
+          vnet_sw_interface_t *swif;
+ 	  u32 bi0;
+	  vlib_buffer_t * b0;
+          udp_header_t * u0, *u1;
+	  dhcpv6_header_t * h0;  // client msg hdr
+          ip6_header_t * ip0, *ip1;
+          ip6_address_t _ia0, *ia0=&_ia0;
+	  u32 next0;
+          u32 error0 = (u32) ~0;
+          dhcpv6_option_t *fwd_opt;
+          dhcpv6_relay_hdr_t *r1;
+          u16 len;
+          dhcpv6_int_id_t *id1;
+          dhcpv6_vss_t *vss1;
+          dhcpv6_client_mac_t *cmac; // client mac
+          ethernet_header_t * e_h0;
+          u8 client_src_mac[6];
+          vlib_buffer_free_list_t *fl;
+          dhcp_vss_t *vss;
+
+	  bi0 = from[0];
+	  to_next[0] = bi0;
+	  from += 1;
+	  to_next += 1;
+	  n_left_from -= 1;
+	  n_left_to_next -= 1;
+
+	  b0 = vlib_get_buffer (vm, bi0);
+
+          h0 = vlib_buffer_get_current (b0);
+
+          /*
+           * udp_local hands us the DHCPV6 header.
+           */
+          u0 = (void *)h0 -(sizeof(*u0));
+          ip0 = (void *)u0 -(sizeof(*ip0));
+          e_h0 = (void *)ip0 - ethernet_buffer_header_size(b0);
+
+          clib_memcpy(client_src_mac, e_h0->src_address, 6);
+
+          switch (h0->u.msg_type) {
+            case DHCPV6_MSG_SOLICIT:
+            case DHCPV6_MSG_REQUEST:
+            case DHCPV6_MSG_CONFIRM:
+            case DHCPV6_MSG_RENEW:
+            case DHCPV6_MSG_REBIND:
+            case DHCPV6_MSG_RELEASE:
+            case DHCPV6_MSG_DECLINE:
+            case DHCPV6_MSG_INFORMATION_REQUEST:
+            case DHCPV6_MSG_RELAY_FORW:
+                /* send to server */
+                break;
+            case DHCPV6_MSG_RELAY_REPL:
+                /* send to client */
+                next0 = DHCPV6_PROXY_TO_SERVER_INPUT_NEXT_SEND_TO_CLIENT;
+                error0 = 0;
+                pkts_to_client++;
+                goto do_enqueue;
+            default:
+                /* drop the packet */
+                pkts_wrong_msg_type++;
+                error0 = DHCPV6_PROXY_ERROR_WRONG_MESSAGE_TYPE;
+                next0 = DHCPV6_PROXY_TO_SERVER_INPUT_NEXT_DROP;
+                goto do_trace;
+
+          }
+
+          /* Send to DHCPV6 server via the configured FIB */
+          rx_sw_if_index = sw_if_index =  vnet_buffer(b0)->sw_if_index[VLIB_RX];
+          rx_fib_idx = im->fib_index_by_sw_if_index [rx_sw_if_index];
+          server = dhcp_get_server(dpm, rx_fib_idx, FIB_PROTOCOL_IP6);
+
+          if (PREDICT_FALSE (NULL == server))
+          {
+              error0 = DHCPV6_PROXY_ERROR_NO_SERVER;
+              next0 = DHCPV6_PROXY_TO_SERVER_INPUT_NEXT_DROP;
+              pkts_no_server++;
+              goto do_trace;
+          }
+
+          server_fib_idx = server->server_fib_index;
+          vnet_buffer(b0)->sw_if_index[VLIB_TX] = server_fib_idx;
+
+
+          /* relay-option header pointer */
+          vlib_buffer_advance(b0, -(sizeof(*fwd_opt)));
+          fwd_opt = vlib_buffer_get_current(b0);
+          /* relay message header pointer */
+          vlib_buffer_advance(b0, -(sizeof(*r1)));
+          r1 = vlib_buffer_get_current(b0);
+
+          vlib_buffer_advance(b0, -(sizeof(*u1)));
+          u1 = vlib_buffer_get_current(b0);
+
+          vlib_buffer_advance(b0, -(sizeof(*ip1)));
+          ip1 = vlib_buffer_get_current(b0);
+
+          /* fill in all that rubbish... */
+          len = clib_net_to_host_u16(u0->length) - sizeof(udp_header_t);
+          copy_ip6_address(&r1->peer_addr, &ip0->src_address);
+
+          r1->msg_type = DHCPV6_MSG_RELAY_FORW;
+          fwd_opt->length = clib_host_to_net_u16(len);
+          fwd_opt->option = clib_host_to_net_u16(DHCPV6_OPTION_RELAY_MSG);
+
+          r1->hop_count++;
+          r1->hop_count = (h0->u.msg_type != DHCPV6_MSG_RELAY_FORW) ? 0 : r1->hop_count;
+
+          if (PREDICT_FALSE(r1->hop_count >= HOP_COUNT_LIMIT))
+            {
+              error0 =  DHCPV6_RELAY_PKT_DROP_MAX_HOPS;
+              next0 = DHCPV6_PROXY_TO_SERVER_INPUT_NEXT_DROP;
+              pkts_no_exceeding_max_hop++;
+              goto do_trace;
+            }
+
+
+          /* If relay-fwd and src address is site or global unicast address  */
+          if (h0->u.msg_type == DHCPV6_MSG_RELAY_FORW &&
+              ((ip0->src_address.as_u8[0] & 0xe0) == 0x20 ||
+               (ip0->src_address.as_u8[0] & 0xfe) == 0xfc))
+            {
+              /* Set link address to zero */
+              r1->link_addr.as_u64[0] = 0;
+              r1->link_addr.as_u64[1] = 0;
+              goto link_address_set;
+            }
+
+          /* if receiving interface is unnumbered, use receiving interface
+           * IP address as link address, otherwise use the loopback interface
+           * IP address as link address.
+           */
+
+          swif = vnet_get_sw_interface (vnm, rx_sw_if_index);
+          if (swif->flags & VNET_SW_INTERFACE_FLAG_UNNUMBERED)
+              sw_if_index = swif->unnumbered_sw_if_index;
+
+          ia0 = ip6_interface_first_global_or_site_address(&ip6_main, sw_if_index);
+          if (ia0 == 0)
+            {
+              error0 = DHCPV6_PROXY_ERROR_NO_INTERFACE_ADDRESS;
+              next0 = DHCPV6_PROXY_TO_SERVER_INPUT_NEXT_DROP;
+              pkts_no_interface_address++;
+              goto do_trace;
+            }
+
+          copy_ip6_address(&r1->link_addr, ia0);
+
+        link_address_set:
+          fl = vlib_buffer_get_free_list (vm, b0->free_list_index);
+
+          if ((b0->current_length+sizeof(*id1)+sizeof(*vss1)+sizeof(*cmac))
+              > fl->n_data_bytes)
+            {
+              error0 = DHCPV6_PROXY_ERROR_PKT_TOO_BIG;
+              next0 = DHCPV6_PROXY_TO_SERVER_INPUT_NEXT_DROP;
+              pkts_too_big++;
+              goto do_trace;
+            }
+
+          id1 = (dhcpv6_int_id_t *) (((uword) ip1) + b0->current_length);
+          b0->current_length += (sizeof (*id1));
+
+          id1->opt.option = clib_host_to_net_u16(DHCPV6_OPTION_INTERFACE_ID);
+          id1->opt.length = clib_host_to_net_u16(sizeof(rx_sw_if_index));
+          id1->int_idx = clib_host_to_net_u32(rx_sw_if_index);
+
+          u1->length =0;
+          if (h0->u.msg_type != DHCPV6_MSG_RELAY_FORW)
+            {
+               cmac = (dhcpv6_client_mac_t *) (((uword) ip1) + b0->current_length);
+               b0->current_length += (sizeof (*cmac));
+               cmac->opt.length =clib_host_to_net_u16(sizeof(*cmac) -
+                                                      sizeof(cmac->opt));
+               cmac->opt.option = clib_host_to_net_u16(DHCPV6_OPTION_CLIENT_LINK_LAYER_ADDRESS);
+               cmac->link_type = clib_host_to_net_u16(1); // ethernet
+               clib_memcpy(cmac->data, client_src_mac, 6);
+               u1->length += sizeof(*cmac);
+            }
+
+          vss = dhcp_get_vss_info(dpm, rx_fib_idx, FIB_PROTOCOL_IP6);
+
+          if (NULL != vss) {
+              vss1 = (dhcpv6_vss_t *) (((uword) ip1) + b0->current_length);
+              b0->current_length += (sizeof (*vss1));
+              vss1->opt.length =clib_host_to_net_u16(sizeof(*vss1) -
+						     sizeof(vss1->opt));
+              vss1->opt.option = clib_host_to_net_u16(DHCPV6_OPTION_VSS);
+              vss1->data[0] = 1;   // type
+              vss1->data[1] = vss->oui >>16 & 0xff;
+              vss1->data[2] = vss->oui >>8  & 0xff;
+              vss1->data[3] = vss->oui & 0xff;
+              vss1->data[4] = vss->fib_id >> 24 & 0xff;
+              vss1->data[5] = vss->fib_id >> 16 & 0xff;
+              vss1->data[6] = vss->fib_id >> 8 & 0xff;
+              vss1->data[7] = vss->fib_id & 0xff;
+              u1->length += sizeof(*vss1);
+          }
+
+          pkts_to_server++;
+          u1->checksum = 0;
+          u1->src_port = clib_host_to_net_u16(UDP_DST_PORT_dhcpv6_to_client);
+          u1->dst_port = clib_host_to_net_u16(UDP_DST_PORT_dhcpv6_to_server);
+
+          u1->length =
+              clib_host_to_net_u16( clib_net_to_host_u16(fwd_opt->length) +
+                                    sizeof(*r1) + sizeof(*fwd_opt) +
+                                    sizeof(*u1) + sizeof(*id1) + u1->length);
+
+          memset(ip1, 0, sizeof(*ip1));
+          ip1->ip_version_traffic_class_and_flow_label = 0x60;
+          ip1->payload_length =  u1->length;
+          ip1->protocol = PROTO_UDP;
+          ip1->hop_limit = HOP_COUNT_LIMIT;
+	      src = (server->dhcp_server.ip6.as_u64[0] ||
+                     server->dhcp_server.ip6.as_u64[1]) ?
+	        &server->dhcp_server.ip6 : &all_dhcpv6_server_address;
+          copy_ip6_address(&ip1->dst_address, src);
+
+
+          ia0 = ip6_interface_first_global_or_site_address
+              (&ip6_main, vnet_buffer(b0)->sw_if_index[VLIB_RX]);
+
+	      src = (server->dhcp_src_address.ip6.as_u64[0] ||
+                     server->dhcp_src_address.ip6.as_u64[1]) ?
+	        &server->dhcp_src_address.ip6 : ia0;
+          if (ia0 == 0)
+            {
+              error0 = DHCPV6_PROXY_ERROR_NO_SRC_ADDRESS;
+              next0 = DHCPV6_PROXY_TO_SERVER_INPUT_NEXT_DROP;
+              pkts_no_src_address++;
+              goto do_trace;
+            }
+
+	  copy_ip6_address (&ip1->src_address, src);
+
+
+          u1->checksum = ip6_tcp_udp_icmp_compute_checksum(vm, b0, ip1,
+                                                           &bogus_length);
+          ASSERT(bogus_length == 0);
+
+          next0 = DHCPV6_PROXY_TO_SERVER_INPUT_NEXT_LOOKUP;
+
+        do_trace:
+          if (PREDICT_FALSE(b0->flags & VLIB_BUFFER_IS_TRACED))
+            {
+               dhcpv6_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 = rx_sw_if_index;
+               tr->sw_if_index = sw_if_index;
+               if (DHCPV6_PROXY_TO_SERVER_INPUT_NEXT_LOOKUP == next0)
+                 copy_ip6_address((ip6_address_t *)&tr->packet_data[0], &server->dhcp_server.ip6);
+            }
+
+        do_enqueue:
+	  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, dhcpv6_proxy_to_server_node.index,
+                               DHCPV6_PROXY_ERROR_RELAY_TO_CLIENT,
+                               pkts_to_client);
+  vlib_node_increment_counter (vm, dhcpv6_proxy_to_server_node.index,
+                               DHCPV6_PROXY_ERROR_RELAY_TO_SERVER,
+                               pkts_to_server);
+  vlib_node_increment_counter (vm, dhcpv6_proxy_to_server_node.index,
+                               DHCPV6_PROXY_ERROR_NO_INTERFACE_ADDRESS,
+                               pkts_no_interface_address);
+  vlib_node_increment_counter (vm, dhcpv6_proxy_to_server_node.index,
+                               DHCPV6_PROXY_ERROR_WRONG_MESSAGE_TYPE,
+                               pkts_wrong_msg_type);
+  vlib_node_increment_counter (vm, dhcpv6_proxy_to_server_node.index,
+                               DHCPV6_PROXY_ERROR_NO_SRC_ADDRESS,
+                               pkts_no_src_address);
+  vlib_node_increment_counter (vm, dhcpv6_proxy_to_server_node.index,
+                               DHCPV6_PROXY_ERROR_PKT_TOO_BIG,
+                               pkts_too_big);
+  return from_frame->n_vectors;
+}
+
+VLIB_REGISTER_NODE (dhcpv6_proxy_to_server_node, static) = {
+  .function = dhcpv6_proxy_to_server_input,
+  .name = "dhcpv6-proxy-to-server",
+  /* Takes a vector of packets. */
+  .vector_size = sizeof (u32),
+
+  .n_errors = DHCPV6_PROXY_N_ERROR,
+  .error_strings = dhcpv6_proxy_error_strings,
+
+  .n_next_nodes = DHCPV6_PROXY_TO_SERVER_INPUT_N_NEXT,
+  .next_nodes = {
+#define _(s,n) [DHCPV6_PROXY_TO_SERVER_INPUT_NEXT_##s] = n,
+    foreach_dhcpv6_proxy_to_server_input_next
+#undef _
+  },
+
+  .format_buffer = format_dhcpv6_proxy_header_with_length,
+  .format_trace = format_dhcpv6_proxy_trace,
+#if 0
+  .unformat_buffer = unformat_dhcpv6_proxy_header,
+#endif
+};
+
+static uword
+dhcpv6_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 = ethernet_get_main (vm);
+  dhcp_proxy_main_t * dm = &dhcp_proxy_main;
+  dhcp_server_t * server;
+  vnet_main_t * vnm = vnet_get_main();
+  int bogus_length;
+
+  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, *u1=0;
+      dhcpv6_relay_hdr_t * h0;
+      ip6_header_t * ip1 = 0, *ip0;
+      ip6_address_t _ia0, * ia0 = &_ia0;
+      ip6_address_t client_address;
+      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;
+      u32 original_sw_if_index = ~0;
+      vnet_sw_interface_t *si0;
+      u32 error0 = (u32)~0;
+      vnet_sw_interface_t *swif;
+      dhcpv6_option_t *r0 = 0, *o;
+      u16 len = 0;
+      u8 interface_opt_flag = 0;
+      u8 relay_msg_opt_flag = 0;
+      ip6_main_t * im = &ip6_main;
+      u32 server_fib_idx, client_fib_idx;
+
+      bi0 = from[0];
+      from += 1;
+      n_left_from -= 1;
+
+      b0 = vlib_get_buffer (vm, bi0);
+      h0 = vlib_buffer_get_current (b0);
+
+      if (DHCPV6_MSG_RELAY_REPL != h0->msg_type)
+        {
+          error0 =  DHCPV6_PROXY_ERROR_WRONG_MESSAGE_TYPE;
+
+        drop_packet:
+          vlib_node_increment_counter (vm, dhcpv6_proxy_to_client_node.index,
+                                       error0, 1);
+
+          f0 = vlib_get_frame_to_node (vm, dm->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, dm->error_drop_node_index, f0);
+          goto do_trace;
+        }
+      /* hop count seems not need to be checked */
+      if (HOP_COUNT_LIMIT < h0->hop_count)
+        {
+          error0 =  DHCPV6_RELAY_PKT_DROP_MAX_HOPS;
+          goto drop_packet;
+        }
+      u0 = (void *)h0 -(sizeof(*u0));
+      ip0 = (void *)u0 -(sizeof(*ip0));
+
+      vlib_buffer_advance (b0, sizeof(*h0));
+      o = vlib_buffer_get_current (b0);
+
+      /* Parse through TLVs looking for option 18 (DHCPV6_OPTION_INTERFACE_ID)
+         _and_ option 9 (DHCPV6_OPTION_RELAY_MSG) option which must be there.
+         Currently assuming no other options need to be processed
+         The interface-ID is the FIB number we need
+         to track down the client-facing interface */
+
+      while ((u8 *) o < (b0->data + b0->current_data + b0->current_length))
+        {
+           if (DHCPV6_OPTION_INTERFACE_ID == clib_net_to_host_u16(o->option))
+             {
+                interface_opt_flag = 1;
+                if (clib_net_to_host_u16(o->length) == sizeof(sw_if_index))
+                    sw_if_index = clib_net_to_host_u32(((dhcpv6_int_id_t*)o)->int_idx);
+                if (sw_if_index >= vec_len (im->fib_index_by_sw_if_index))
+                  {
+                    error0 = DHCPV6_PROXY_ERROR_WRONG_INTERFACE_ID_OPTION;
+                    goto drop_packet;
+                  }
+             }
+           if (DHCPV6_OPTION_RELAY_MSG == clib_net_to_host_u16(o->option))
+             {
+                relay_msg_opt_flag = 1;
+                r0 = vlib_buffer_get_current (b0);
+             }
+           if ((relay_msg_opt_flag == 1) && (interface_opt_flag == 1))
+             break;
+           vlib_buffer_advance (b0, sizeof(*o) + clib_net_to_host_u16(o->length));
+           o = (dhcpv6_option_t *) (((uword) o) + clib_net_to_host_u16(o->length) + sizeof(*o));
+        }
+
+      if ((relay_msg_opt_flag == 0) || (r0 == 0))
+        {
+    	  error0 = DHCPV6_PROXY_ERROR_NO_RELAY_MESSAGE_OPTION;
+    	  goto drop_packet;
+        }
+
+      if ((u32)~0 == sw_if_index)
+        {
+          error0 = DHCPV6_PROXY_ERROR_NO_CIRCUIT_ID_OPTION;
+          goto drop_packet;
+        }
+
+      //Advance buffer to start of encapsulated DHCPv6 message
+      vlib_buffer_advance (b0, sizeof(*r0));
+
+      client_fib_idx = im->fib_index_by_sw_if_index[sw_if_index];
+      server = dhcp_get_server(dm, client_fib_idx, FIB_PROTOCOL_IP6);
+
+      if (NULL == server)
+      {
+    	  error0 = DHCPV6_PROXY_ERROR_NO_SERVER;
+          goto drop_packet;
+      }
+
+      server_fib_idx = im->fib_index_by_sw_if_index
+          [vnet_buffer(b0)->sw_if_index[VLIB_RX]];
+
+      if (server_fib_idx != server->server_fib_index ||
+          ip0->src_address.as_u64[0] != server->dhcp_server.ip6.as_u64[0] ||
+          ip0->src_address.as_u64[1] != server->dhcp_server.ip6.as_u64[1])
+        {
+          //drop packet if not from server with configured address or FIB
+          error0 = DHCPV6_PROXY_ERROR_BAD_SVR_FIB_OR_ADDRESS;
+          goto drop_packet;
+        }
+
+      vnet_buffer (b0)->sw_if_index[VLIB_TX] = original_sw_if_index
+          = sw_if_index;
+
+      swif = vnet_get_sw_interface (vnm, original_sw_if_index);
+      if (swif->flags & VNET_SW_INTERFACE_FLAG_UNNUMBERED)
+          sw_if_index = swif->unnumbered_sw_if_index;
+
+
+      /*
+       * udp_local hands us the DHCPV6 header, need udp hdr,
+       * ip hdr to relay to client
+       */
+      vlib_buffer_advance (b0, -(sizeof(*u1)));
+      u1 = vlib_buffer_get_current (b0);
+
+      vlib_buffer_advance (b0, -(sizeof(*ip1)));
+      ip1 = vlib_buffer_get_current (b0);
+
+      copy_ip6_address(&client_address, &h0->peer_addr);
+
+      ia0 = ip6_interface_first_address (&ip6_main, sw_if_index);
+      if (ia0 == 0)
+        {
+          error0 = DHCPV6_PROXY_ERROR_NO_INTERFACE_ADDRESS;
+          goto drop_packet;
+        }
+
+      len =  clib_net_to_host_u16(r0->length);
+      memset(ip1, 0, sizeof(*ip1));
+      copy_ip6_address(&ip1->dst_address, &client_address);
+      u1->checksum = 0;
+      u1->src_port = clib_net_to_host_u16 (UDP_DST_PORT_dhcpv6_to_server);
+      u1->dst_port = clib_net_to_host_u16 (UDP_DST_PORT_dhcpv6_to_client);
+      u1->length = clib_host_to_net_u16 (len + sizeof(udp_header_t));
+
+      ip1->ip_version_traffic_class_and_flow_label =
+          ip0->ip_version_traffic_class_and_flow_label &
+          0x00000fff;
+      ip1->payload_length =  u1->length;
+      ip1->protocol = PROTO_UDP;
+      ip1->hop_limit = HOP_COUNT_LIMIT;
+      copy_ip6_address(&ip1->src_address, ia0);
+
+      u1->checksum = ip6_tcp_udp_icmp_compute_checksum(vm, b0, ip1,
+                                                       &bogus_length);
+      ASSERT(bogus_length == 0);
+
+      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));
+      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 (0x86dd);
+
+      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);
+	}
+
+      /* $$$ consider adding a dynamic next to the graph node, for performance */
+      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))
+        {
+          dhcpv6_proxy_trace_t *tr = vlib_add_trace (vm, node,
+                                                     b0, sizeof (*tr));
+          tr->which = 1; /* to client */
+          if (ia0)
+              copy_ip6_address((ip6_address_t*)tr->packet_data, ia0);
+          tr->error = error0;
+          tr->original_sw_if_index = original_sw_if_index;
+          tr->sw_if_index = sw_if_index;
+        }
+    }
+  return from_frame->n_vectors;
+
+}
+
+VLIB_REGISTER_NODE (dhcpv6_proxy_to_client_node, static) = {
+  .function = dhcpv6_proxy_to_client_input,
+  .name = "dhcpv6-proxy-to-client",
+  /* Takes a vector of packets. */
+  .vector_size = sizeof (u32),
+
+  .n_errors = DHCPV6_PROXY_N_ERROR,
+  .error_strings = dhcpv6_proxy_error_strings,
+  .format_buffer = format_dhcpv6_proxy_header_with_length,
+  .format_trace = format_dhcpv6_proxy_trace,
+#if 0
+  .unformat_buffer = unformat_dhcpv6_proxy_header,
+#endif
+};
+
+static clib_error_t *
+dhcp6_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;
+
+  /* RFC says this is the dhcpv6 server address  */
+  all_dhcpv6_server_address.as_u64[0] = clib_host_to_net_u64 (0xFF05000000000000);
+  all_dhcpv6_server_address.as_u64[1] = clib_host_to_net_u64 (0x00010003);
+
+  /* RFC says this is the server and agent address */
+  all_dhcpv6_server_relay_agent_address.as_u64[0] = clib_host_to_net_u64 (0xFF02000000000000);
+  all_dhcpv6_server_relay_agent_address.as_u64[1] = clib_host_to_net_u64 (0x00010002);
+
+  udp_register_dst_port (vm, UDP_DST_PORT_dhcpv6_to_client,
+                         dhcpv6_proxy_to_client_node.index, 0 /* is_ip6 */);
+
+  udp_register_dst_port (vm, UDP_DST_PORT_dhcpv6_to_server,
+                         dhcpv6_proxy_to_server_node.index, 0 /* is_ip6 */);
+
+  return 0;
+}
+
+VLIB_INIT_FUNCTION (dhcp6_proxy_init);
+
+int
+dhcp6_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 mfib_prefix_t all_dhcp_servers = {
+      .fp_len = 128,
+      .fp_proto = FIB_PROTOCOL_IP6,
+      .fp_grp_addr = {
+          .ip6 = all_dhcpv6_server_relay_agent_address,
+      }
+  };
+
+  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;
+
+  rx_fib_index = mfib_table_find_or_create_and_lock(FIB_PROTOCOL_IP6,
+                                                    rx_table_id);
+
+  if (is_del)
+    {
+      rc = dhcp_proxy_server_del (FIB_PROTOCOL_IP6, rx_fib_index);
+
+      if (0 == rc)
+      {
+          mfib_table_entry_delete(rx_fib_index,
+                                  &all_dhcp_servers,
+                                  MFIB_SOURCE_DHCP);
+          mfib_table_unlock(rx_fib_index, FIB_PROTOCOL_IP6);
+      }
+    }
+  else
+    {
+     const fib_route_path_t path_for_us = {
+          .frp_proto = FIB_PROTOCOL_IP6,
+          .frp_addr = zero_addr,
+          .frp_sw_if_index = 0xffffffff,
+          .frp_fib_index = ~0,
+          .frp_weight = 0,
+          .frp_flags = FIB_ROUTE_PATH_LOCAL,
+      };
+     if (dhcp_proxy_server_add (FIB_PROTOCOL_IP6, addr, src_addr,
+                                rx_fib_index, server_table_id))
+     {
+         mfib_table_entry_path_update(rx_fib_index,
+                                      &all_dhcp_servers,
+                                      MFIB_SOURCE_DHCP,
+                                      &path_for_us,
+                                      MFIB_ITF_FLAG_FORWARD);
+         /*
+          * Each interface that is enabled in this table, needs to be added
+          * as an accepting interface, but this is not easily doable in VPP.
+          * So we cheat. Add a flag to the entry that indicates accept form
+          * any interface.
+          * We will still only accept on v6 enabled interfaces, since the
+          * input feature ensures this.
+          */
+         mfib_table_entry_update(rx_fib_index,
+                                 &all_dhcp_servers,
+                                 MFIB_SOURCE_DHCP,
+                                 MFIB_ENTRY_FLAG_ACCEPT_ALL_ITF);
+         mfib_table_lock(rx_fib_index, FIB_PROTOCOL_IP6);
+     }
+    }
+
+  mfib_table_unlock(rx_fib_index, FIB_PROTOCOL_IP6);
+
+  return (rc);
+}
+
+static clib_error_t *
+dhcpv6_proxy_set_command_fn (vlib_main_t * vm,
+                           unformat_input_t * input,
+                           vlib_cli_command_t * cmd)
+{
+  ip46_address_t addr, src_addr;
+  int set_server = 0, set_src_address = 0;
+  u32 rx_table_id = 0, server_table_id = 0;
+  int is_del = 0;
+
+  while (unformat_check_input(input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (input, "server %U",
+                    unformat_ip6_address, &addr.ip6))
+	 set_server = 1;
+      else if (unformat(input, "src-address %U",
+			unformat_ip6_address, &src_addr.ip6))
+	  set_src_address =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, "delete") ||
+                unformat (input, "del"))
+           is_del = 1;
+      else
+        break;
+    }
+
+  if (is_del || (set_server && set_src_address))
+  {
+      int rv;
+
+      rv = dhcp6_proxy_set_server (&addr, &src_addr, rx_table_id,
+                                   server_table_id, is_del);
+
+      //TODO: Complete the errors
+      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);
+}
+
+VLIB_CLI_COMMAND (dhcpv6_proxy_set_command, static) = {
+  .path = "set dhcpv6 proxy",
+  .short_help = "set dhcpv6 proxy [del] server <ipv6-addr> src-address <ipv6-addr> "
+		  "[server-fib-id <fib-id>] [rx-fib-id <fib-id>] ",
+  .function = dhcpv6_proxy_set_command_fn,
+};
+
+static u8 *
+format_dhcp6_proxy_server (u8 * s, va_list * args)
+{
+  dhcp_server_t * server = va_arg (*args, dhcp_server_t *);
+  ip6_fib_t * rx_fib, * server_fib;
+
+  if (NULL == server)
+    {
+      s = format (s, "%=40s%=40s%=14s%=14s", "Server Address", "Source Address",
+                  "Server FIB", "RX FIB");
+      return s;
+    }
+
+  server_fib = ip6_fib_get(server->server_fib_index);
+  rx_fib = ip6_fib_get(server->rx_fib_index);
+
+
+  s = format (s, "%=40U%=40U%=14u%=14u",
+              format_ip46_address, &server->dhcp_server, IP46_TYPE_ANY,
+              format_ip46_address, &server->dhcp_src_address, IP46_TYPE_ANY,
+              server_fib->table_id, rx_fib->table_id);
+  return s;
+}
+
+static int
+dhcp6_proxy_show_walk (dhcp_server_t *server,
+                       void *ctx)
+{
+    vlib_main_t * vm = ctx;
+
+    vlib_cli_output (vm, "%U", format_dhcp6_proxy_server, server);
+
+    return (1);
+}
+
+static clib_error_t *
+dhcpv6_proxy_show_command_fn (vlib_main_t * vm,
+                            unformat_input_t * input,
+                            vlib_cli_command_t * cmd)
+{
+  vlib_cli_output (vm, "%U", format_dhcp6_proxy_server, NULL /* header line */);
+
+  dhcp_proxy_walk(FIB_PROTOCOL_IP6, dhcp6_proxy_show_walk, vm);
+
+  return (NULL);
+}
+
+VLIB_CLI_COMMAND (dhcpv6_proxy_show_command, static) = {
+  .path = "show dhcpv6 proxy",
+  .short_help = "Display dhcpv6 proxy info",
+  .function = dhcpv6_proxy_show_command_fn,
+};
+
+static clib_error_t *
+dhcpv6_vss_command_fn (vlib_main_t * vm,
+                       unformat_input_t * input,
+                       vlib_cli_command_t * cmd)
+{
+  int is_del = 0, got_new_vss=0;
+  u32 oui=0;
+  u32 fib_id=0, tbl_id=~0;
+
+  while (unformat_check_input(input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (input, "oui %d", &oui))
+          got_new_vss = 1;
+      else if (unformat (input, "vpn-id %d", &fib_id))
+          got_new_vss = 1;
+      else if (unformat (input, "table %d", &tbl_id))
+          got_new_vss = 1;
+      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.");
+
+  if (is_del || got_new_vss)
+    {
+      int rv;
+
+      rv = dhcp_proxy_set_vss(FIB_PROTOCOL_IP6, tbl_id, oui, fib_id, is_del);
+      switch (rv)
+        {
+        case 0:
+          return 0;
+
+        case VNET_API_ERROR_NO_SUCH_FIB:
+            return clib_error_return (0, "vss info (oui:%d, vpn-id:%d)  not found in table %d.",
+                                      oui, fib_id, tbl_id);
+
+        case VNET_API_ERROR_NO_SUCH_ENTRY:
+            return clib_error_return (0, "vss for table %d not found in pool.",
+                                      tbl_id);
+
+        default:
+          return clib_error_return (0, "BUG: rv %d", rv);
+        }
+    }
+  else
+      return clib_error_return (0, "parse error`%U'",
+                                format_unformat_error, input);
+
+}
+
+VLIB_CLI_COMMAND (dhcpv6_proxy_vss_command, static) = {
+  .path = "set dhcpv6 vss",
+  .short_help = "set dhcpv6 vss table <table-id> oui <oui> vpn-idx <vpn-idx>",
+  .function = dhcpv6_vss_command_fn,
+};
+
+static clib_error_t *
+dhcpv6_vss_show_command_fn (vlib_main_t * vm,
+                            unformat_input_t * input,
+                            vlib_cli_command_t * cmd)
+
+{
+  dhcp_vss_walk(FIB_PROTOCOL_IP6, dhcp_vss_show_walk, vm);
+
+  return (NULL);
+}
+
+VLIB_CLI_COMMAND (dhcpv6_proxy_vss_show_command, static) = {
+  .path = "show dhcpv6 vss",
+  .short_help = "show dhcpv6 VSS",
+  .function = dhcpv6_vss_show_command_fn,
+};
+
+static clib_error_t *
+dhcpv6_link_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;
+  ip6_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 = ip6_interface_first_address(&ip6_main, sw_if_index);
+            if (ia0)
+              {
+                  vlib_cli_output (vm, "%=20s%=48s", "interface", "link-address");
+
+                  vlib_cli_output (vm, "%=20U%=48U",
+                                   format_vnet_sw_if_index_name, vnm, sw_if_index0,
+                                   format_ip6_address, ia0);
+              } else
+                vlib_cli_output (vm, "%=34s%=20U", "No IPv6 address configured on",
+                                 format_vnet_sw_if_index_name, vnm, sw_if_index);
+        } else
+          break;
+    }
+
+  return 0;
+}
+
+VLIB_CLI_COMMAND (dhcpv6_proxy_address_show_command, static) = {
+  .path = "show dhcpv6 link-address interface",
+  .short_help = "show dhcpv6 link-address interface <interface>",
+  .function = dhcpv6_link_address_show_command_fn,
+};